Voltage Sensing Battery Isolators

Submitted: Tuesday, Mar 08, 2005 at 01:58

Member - Sand Man (SA)

Voltage Sensing Battery Isolator

I have sought a better understanding of how the modern voltage sensing battery isolator works and obtained some interesting information from Alan Johnson from Piranha off Road Products. I have reproduced the details here, for the reference of anyone who wishes it.

Now I am not specifically “pushing” the Piranha product, or attempting to criticise those who, for one reason or another, choose an alternative, or cheaper solution. But there are certain risks in a basic parallel system that people should be aware of.

I asked three specific questions:-
1. Is the primary battery disconnected while the secondary battery is receiving its charge?
2. Are the two batteries electrically separated?
3. Are they ever connected in parallel?

Reply:-

No, the primary battery is NOT disconnected while the secondary battery is receiving its charge.
Yes, the two batteries are electrically separated. And sometimes?? they are, sort of, connected in parallel.

To understand the concept of voltage sensing battery charging/management systems, we need to discuss a few basic ideas first.

Parallel means the two “tanks” of energy, (batteries) are connected positive to positive, negative to negative.
This creates, electrically, not two separate batteries but one bigger battery. They charge and discharge as one.
In a good parallel system, both batteries should be identical (i.e. same size, age, design and capacity).

In a Voltage Sensing system, the batteries do not parallel, they never discharge together and the charging occurs similar to parallel, but not true to the meaning of the term parallel.

1. The car starts on one battery only. (NOT Parallel)
2. The main battery must achieve a pre-determined voltage, 13.5+ volts, before the auxiliary battery is connected to the charging system (NOT Parallel)
3. When the main battery is charged, power from the alternator takes the path of least resistance, therefore into the auxiliary battery via the main battery first. (Parallel – perhaps?)
4. If the main battery drops below the threshold of 12.8 volts, the auxiliary battery is disconnected from the charging circuit. (NOT Parallel)
5. If excessive current is sensed the auxiliary is disconnected. (NOT Parallel)
6. If the auxiliary battery is damaged and will not accept a charge, the unit will disconnect the auxiliary battery. (NOT Parallel)

Voltage Sensing systems offers the following advantages to those who wish to use dissimilar batteries.
• Faster recovery time
• Use of dissimilar batteries (size, age, design and capacity, wet cell, AGM, etc.)
• Better reliability
• Longer battery life
• Surge/Spike protection
• Virtually no voltage drop across system
• Fail Safe – If the system “dies”, only the auxiliary will go flat

Parallel System
A basic parallel system just does not do the job. If one was to (hypothetically), disconnect the main battery completely, the modern vehicles computer management system would sense no charge from the alternator, resulting in “limp home” mode, or possibly, complete shutdown. This is not acceptable for any outback traveler and even worse, if the system did totally fail – the engine, fuel, or spark could be jeopardised.
On start up, parallel systems can “mask” the fact that the main battery is flat, or damaged, i.e. dead cell.
The auxiliary battery will do most of the work, starting, cranking and when the auxiliary is flat/depleted, the car will not start, because BOTH batteries will now be in a discharged state.
Bill


I'm diagonally parked in a parallel Universe!
Thumbs UpThanks 0
Back to Forum
Thread Watch Alert Moderator FAQ
ThreadID: 21042 Replies: 15
Views: 10643 FollowUps: 42
This Thread has been Archived
Thread Summary
AnswerID: 101538   Submitted: Tuesday, Mar 08, 2005 at 07:39

DukeAtty replied:

and this is why everytime a friend wants a basic dual batt setup we go with the very easy to use Piranha 150 or now (180) amp voltage sensing battery isolator...
300 bucks and around 1.5hrs later the job is done... Too easy..
Thumbs UpThanks 0
Reply 1 of 15
AnswerID: 101546   Submitted: Tuesday, Mar 08, 2005 at 08:58

Leroy replied:

Sandman,

Very Good Marketers those Piranha people. Their isolators are nothing special. The aux batt is charged in parallel and switched in and out depending on what voltage it senses. Redarc, ARB etc do the same except they have a mechanical solenoid. Change your words of 'not parallel' and 'parallel' to 'in circuit' and 'out of circuit' cause that's what the isolator does - switching.

On my 3.0GU I had to use another batt to start it as the lights were left on and after it was running I removed the battery and the vehicle kept running until I put the flat battery back in. The battery I put in was so flat the central locking didn't work, no dash lights, nothing. But the engine kept running. I don't think it's all doom and gloom when a batt fails just a pain in the ass!

Leroy
Thumbs UpThanks 0
Reply 2 of 15
FollowupID: 359449   Submitted: Tuesday, Mar 08, 2005 at 10:05

Member - Captain (WA) posted:

Hi Sandman,

Gotta agree with Leroy here, just a fancy "solenoid" that switches off/on depending on batt voltage instead of ignition switch position like simple solenoids.

While the Piranaha does a good job, IMHO the Redarc is much better value for money. Cost is $100 trade for 100 amp (400 surge) and readily available from places like Coventrys (well, here in WA anyway) and is made in South Australia. Or if you want the name, buy the ARB one, "only" $200+ and made in Mexico!!!

But if you want the "best" isolator IMHO, get the Rotronic. It isolates and charges each battery individually and can truly handle dissimilair batts. But for the top of the range (2 batts in vehicle, 1 in trailer) you are looking at over $1,000.

Me, I simply have the Redarc, ultra reliable and a realistic price and does what I need.

Cheers

Captain
Its not what you drive, but how you drive it!
LC 200 + AOR Quantum
Thumbs UpThanks 0
FollowUp 1 of 12
FollowupID: 359457   Submitted: Tuesday, Mar 08, 2005 at 12:09

Mad Dog (Australia) posted:

I gotta agree also.
The Redarc will handle all of the points mentioned above except 5 and 6

>5. If excessive current is sensed the auxiliary is disconnected. (NOT Parallel)
>6. If the auxiliary battery is damaged and will not accept a charge, the unit will disconnect the auxiliary battery. (NOT Parallel)

Point 5 is very easily taken care of with the fuse or circuit breaker

Dunno how they acheive point 6 but it's pretty cool
Thumbs UpThanks 0
FollowUp 2 of 12
FollowupID: 359459   Submitted: Tuesday, Mar 08, 2005 at 12:19

Member - Captain (WA) posted:

Hi Mad Dog,

With >5, the Redarc disconnects when bat voltage drops below 12.6V (from memory), so if exccessive current eg. winch, it drops out on low voltage. All depends on what one calls excessive current I suppose. I need to use a manual overide switch to use both batts when winching as this is "excessive" current.

As for >6, gotta agree its pretty cool, but how does it sense damage as opposed to extremely low discharge or full charge? - good question.

Cheers

Captain

Its not what you drive, but how you drive it!
LC 200 + AOR Quantum
Thumbs UpThanks 0
FollowUp 3 of 12
FollowupID: 359461   Submitted: Tuesday, Mar 08, 2005 at 12:34

Member - Jeff M (WA) posted:

Yup, they really over complicated what is a simple theroy. They are pushing hard to try and justify the extra expense of their product.
My Arrid Smart Relay with my own voltage sensing module added to it works brilliantly and is 1/3 of the price of the cheapest pirahna. The Redarc is also another excellent option.

I run disimilar batteries and I draw a higher load than most people (as my cooler is between 6-7amps draw) and I can tell you that there is no need for these fancy expensive setups for 99% of what you guys do.

But JMHO.

Thumbs UpThanks 0
FollowUp 4 of 12
FollowupID: 359519   Submitted: Tuesday, Mar 08, 2005 at 22:06

Mainey (WA) posted:

Have to disagree with some 'opinions' here, mainly because they are just personal opinions and not actually backed up by any facts...

The Piranha offers the following advantages that no Solenoid can match;

(Quote)Voltage Sensing systems offers the following advantages to those who wish to use DIS-SIMILAR batteries.
• Faster recovery time
• Use of dissimilar batteries (size, age, design and capacity, wet cell, AGM, etc.)
• Better reliability
• Longer BATTERY life
• Virtually no voltage drop across system
• Fail Safe – If the system “dies”, only the auxiliary will go flat (end quote)

Having had a Solenoid system
and then a Piranha DBE150S system
and now a Rotronics Electronics system
yes, all on the same vehicle, I believe I'm in a position whereby I can state my own experience with all three systems on the same vehicle and same battery system!

# I question if anyone presently using a Solenoid system, has in fact ever had a Piranha Electronic system or a Rotronics Electronic system on their vehicle and has removed the Electronic system because they believed they did not work, and can state their Solenoid system is superior ?

##…….NO..... I really didn't think so 

The facts are undisputed on stated on the various websites available that a Solenoid system will ONLY recharge the Auxiliary battery to a MAX of 80%.....

A Solenoid system will only recharge two IDENTICAL batteries.
Yes, I actually E-mailed the MD of Redarc and asked him that precise question and I received a reply from him stating this is in fact true.

A Solenoid system works on a different principal to an Electronic system, both have their place, if you can't afford an Electronic system, then a Solenoid is cheaper alternative, however the facts are that an Electronic system will recharge your Auxiliary battery between 95% and 100% whereby a Solenoid system will only recharge it to a maximum of 80% … not my opinion, a fact.
Thumbs UpThanks 0
FollowUp 5 of 12
FollowupID: 359522   Submitted: Tuesday, Mar 08, 2005 at 22:19

Mad Dog (Australia) posted:

heha...somehow I knew you'd popup here Mainey.

Don't believe all the marketing claptrap you read on websites Mainey. Some manufactures are more honest than others.

You said "I believe I'm in a position whereby I can state my own experience with all three systems on the same vehicle and same battery system!"

So tell us about your experiences with all 3 systems

Thumbs UpThanks 0
FollowUp 6 of 12
FollowupID: 359535   Submitted: Wednesday, Mar 09, 2005 at 00:57

Member - Captain (WA) posted:

Well Mainey, no-one here (well, not me anyway) is claiming a solenoid system is technically better than the piranaha. BUT, they are not any worse either and are far more economical to boot.

You seem to conviniently forget the fact that the piranha is merely an electronic version of a solenoid which "opens and closes" depending on voltage, not the position of the ignition key. A "smart" solenoid, like the redarc, does the same thing as the Piranaha, but it uses a mechanical solenoid.

The piranha DOESN'T charge each battery individually, it charges the main first and ONLY when it reaches the target voltage (13.6 I believe) will it join the aux battery (same as smart solenoid).

The Rotronics charge/Isolater battery charger is the ONLY battery isolator/charger that truly charges each battery individually based on voltage and priority to the main battery (that I am aware of). But this feature is not on their base models, so just because one has a Rotronics isolator does NOT mean one has a true charge/isolator.

As for claims of better for disimilar bats etc..., that is partially true! But it is also the same for the smart solenoids to!!! The reason for it is that the main battery is charged to its correct voltage first and only then is the second (potentially dissimilair) battery charged. Theoretically the 2nd battery will now charge faster because the main is already fully charged. Just a twist on facts for slick marketing and partially true (what all good advertising consists of!!!)

But for proper charging of dissimilair batteries in the quickest time, once again the Rotronics charge/isolator is the best. But bear in mind you are looking at $750 - $1100 depending on options and features, far from affordable for the average 4WDriver.

As for "only recharge it to a maximum of 80% … not my opinion, a fact", well sorry but you are a victim of good advertising and misleading information again. Under CERTAIN conditions, it can true but once again, its the same for piranaha and smart solenoids.

As for "facts are undisputed", you mysteriously forget to state under what conditions or what proof. For example "longer battery life and better reliability" are opinions, not facts, without a documented study.

On the surface, dual battery isolation and charging appears an easy subject, but once you start to dig deeper and understand some electronic theory behind it, one soon realises everything is a compromise and one has to choose what suits their requirements best. About the only isolator that can fully meet ALL requirements is the Rotronics charge/isolate, but what a price. Also, it has more electronics so more potential areas to go wrong.

At the end of the day, a simple ignition switched isolator will surfice for many 4WDrivers, then comes a smart solenoid and piranaha for virtually the rest, with a Rotronics charge/isolate only required for the very few who really need the best (gee's, I must sound like an ad for Rotronics by now and I don't even have one!!!).

This thread started out as a decent discussion of various isolation systems before one got confused with marketing hype vs electronic theory. This reply is long enough already and it has really only touched the surface. To fully understand every combination and advantage/disadvantage of every system, one can read some good books on the subject to get a true and proper understanding, not regurgitate some slick marketing advertising.

Cheers

Captain

PS. yes, I am an Engineer

Its not what you drive, but how you drive it!
LC 200 + AOR Quantum
Thumbs UpThanks 0
FollowUp 7 of 12
FollowupID: 359556   Submitted: Wednesday, Mar 09, 2005 at 10:45

drivesafe posted:

Sorry Mainey but I have to agree with Captain about Relays ( solenoids ) not being able to charge batteries over 80%.

If the charging system can get a main battery to around 95% to 100% then using a relay will mean that the auxiliary battery of similar type to the main battery, can be charged to the same level.

Other things like incorrect cabling and so on could be the problem where a second battery is not charging properly.

A relay will pass both the voltage and providing the relay’s capacity is high enough, the current required to charge the second battery to the same level that the charging system can produce it.

This is a physical fact and main benefit of using relays for a whole host of operations around a vehicle especially in situations where the slightest lose of voltage can result in some form of problem.

Cheers
Thumbs UpThanks 0
FollowUp 8 of 12
FollowupID: 359564   Submitted: Wednesday, Mar 09, 2005 at 11:12

TheUndertaker posted:

Hey captain, just a query ,you state that the rotronics at $750/$1100 is far from affordable for the average 4x4 driver ,ever added up the costs of your toys ,eg.vehicle,b/bar /winch/ drawer sys/ tyres/suspension upgrade/camping gear/trailer/fridges/radios/ ect ect ect,, a $1000. pales into insignificance,,,,,, the only diference between men and boys is the cost of toys. have a good day.
Thumbs UpThanks 0
FollowUp 9 of 12
FollowupID: 359570   Submitted: Wednesday, Mar 09, 2005 at 12:56

Member - Jeff M (WA) posted:

Mainy you say you have "facts" not opinions.... Mate all I saw was some satements in point form, most of which weren't even right.

BTW - I had an electronic system which failed, that's why I replaced it with the Arrid.

Mainy, please explain to me how the Pirahna is going to have a "faster recovery time" than my setup? My setup allows the starter to reach the correct voltage before charging the Aux?

I run Disimilar batteries. No problems.

How does it improve my battery life, is it the same way a Hiclone saves fuel?

How does an electronic isolater cause less voltage drop than a relay? It doesn't.

If any part of my system "dies" the batteries automatically isolate. Same as your U-Buet system. No advantage there....

Mate I'm starting to think you might have been had...

Also this "fact" abut 95% charge vs 80% charge is complete crap. My Wet Cell Deep Cycle at rest from is at approx 12.7-12.8v from charging off the vehicle. This battery is over 12 months old and if you do your research you'll find that this is almost fully charged. I'd also like to know HOW the electronic systems charge my wet cell more than a direct connection to the charging source (as a relay is).

So here you go Mainy:
"# I question if anyone presently using a Solenoid system, has in fact ever had a Piranha Electronic system or a Rotronics Electronic system on their vehicle and has removed the Electronic system because they believed they did not work, and can state their Solenoid system is superior ?

##¡K¡K.NO..... I really didn't think so ƒº "

I think it was unwise for you to assume this, because I am not person you didn't think existed.

Thank you.

Thumbs UpThanks 0
FollowUp 10 of 12
FollowupID: 359571   Submitted: Wednesday, Mar 09, 2005 at 12:59

Member - Jeff M (WA) posted:

I meant to say:
I think it was unwise for you to assume this, because I AM that person you didn't think existed.

(typo).
Thumbs UpThanks 0
FollowUp 11 of 12
FollowupID: 359693   Submitted: Wednesday, Mar 09, 2005 at 22:45

Member - Captain (WA) posted:

Hi Undertaker,

I agree that if one adds up the price of all their "toys" that a Rotronics would only be a small percentage. Its just that IMHO the rotronics at $1150 (the model I was after) could not be justified. It cost me $100 for the redarc and has served me well (my 2nd battery is over 3 years old and still has over 12.7 V ).

Even if my 2nd bat dies tomorrow and I only get 3 years from it, the best one could expect under ideal conditions is say 6 years for a rotronics isolated battery. So, the best potential saving a rotronics will give me is $170 every 3 years. At ~$1000 extra cost, I can think of a LOT more goodies I would rather spend my money on. Others may decide differently, all about personal choice.

Cheers

Captain
Its not what you drive, but how you drive it!
LC 200 + AOR Quantum
Thumbs UpThanks 0
FollowUp 12 of 12
AnswerID: 101580   Submitted: Tuesday, Mar 08, 2005 at 15:01

geocacher (djcache) replied:

Point 6 could be easily achieved by monitoring the auxilliary battery voltage and charge current, which is what I'm guessing it does. The Pirahna with any form of in cab battery status monitoring is not the only way to go. But it's pretty damn good. Without it you have no idea either is stuffed until you really need it.

I use the basic DBS180 and made my own battery monitor with LED bar display and the ability to switch between battery 1 & 2 using the LM3914 (it's an IC) based Dick Smith kit for about $25 inc a box to put it in. (Even added the ability to push a test button and light it up with the ignition off, but that's just OTT)

No moving parts to foul up or fail in a completely electronic system either. Doesn't matter if you drown it, fill it up with mud or similar.

And for winching or starting off the auxilliary battery I bridge the two out with a marine isolator switch bypassing the DBS180.

Dave
Thumbs UpThanks 0
Reply 3 of 15
FollowupID: 359504   Submitted: Tuesday, Mar 08, 2005 at 20:28

hl posted:

Hi,

There seems to be as much snake oil used in the manufacture of battery isolators then in solar regulators.
Sure, some of the features MAY be useful, but if you look after your batteries you probably know what state they are in and replace them in good time when they start going bad.
A friend of mine has used the simple solenoid system for years without a problem, I have a voltage sensing device made by GSL. It works ok too but I am not sure if it's worth the extra trouble.

The biggest danger I can see in a solenoid setup is if the aux battery develops a shorted cell (not all that common, really). The main battery (and alternator) will then try and bring it up to 14V and a lot of current will flow, enough to either boil the faulty battery dry or worse, make some of the wires under the bonnet get pretty hot. So, a circuit breaker of say 70amp or 100amp rating between the 2 batteries is a must.

Cheers
Thumbs UpThanks 0
FollowUp 1 of 2
FollowupID: 359527   Submitted: Tuesday, Mar 08, 2005 at 22:59

B0XER posted:

Cicuit breakers between the two batteries can be a hassle - if you flatten the aux below 10.5 volts also the currect supplied by the main battery/alternator when it is eventually switched into circuit after start up will be higher than these nominal figures (it can be close to the full fault current of the battery)

Reading this thread I think a few people have lost the underlying fact of these systems is that whether it is electronic or solenoid is irrelevant - the comparisons made are purely on how the aux battery is connected into circuit. Some systems truely isolate each battery in turn to the charge circuit of the vehicle and others simply parallel the aux battery across the main. Either system works although the full isolation system is optimal.
To say parallel systems are poor design is fallacy - they work fine for most people. The chance of shorted cells etc causing problems are minute. Batteries are connected in parallel across a common charge circuit in many facets of industry - has anyone seen inside a local telephone exchange?? Boats generally charge two batteries in parallel also (although it can be manually overidden)
Thumbs UpThanks 0
FollowUp 2 of 2
AnswerID: 101649   Submitted: Tuesday, Mar 08, 2005 at 23:05

B0XER replied:

Furthermore Sandmans description above of the Piranha system is emulated by most solenoid systems also - I have the RedArc and it operates in the same way - it still is in parallel, no matter what the Piranha salesman says - it just chooses when to switch into parralel and when not to. To use state of charge to outline path of least resistance equals more current into the aux battery is misleading - the circuit for theory's sake is indeed in parallel. Two resistors of different values connected across a battery are still a parallel circuit eventhough current draw is different

The only true isolator I have seen is the high end Rotronics (not the standard one) It connects batteries across the vehicle charge circuit independantly of each other
Thumbs UpThanks 0
Reply 4 of 15
EOTrackMe - GPS & Satellite Tracking Service Sponsor Message
Tracking for travellers with online mapping & privacy settings. Almost any phone, tablet, PC or satellite device can connect to EOTrackMe. Ideal for families & safety. Sign up free (Members only).
www.exploroz.com/EOTrackMe/Default.aspx
AnswerID: 101654   Submitted: Tuesday, Mar 08, 2005 at 23:25

geocacher (djcache) replied:

To say that a solenoid system will only charge both batteries to 80% is a complete fallacy. IF (big if) that were correct then an alternator charging one battery alone would only charge your main battery to 80% also.

The only reason either would charge to 80% is if something was limiting the alternator to a lower output voltage and a mechanical switch of extremely low resistance will not do that. (It must be low resistance or the heat generated across the contacts would weld them closed rendering it permanently in one state.)

The solenoid is only a mechanical switch joining both positive terminals so that both batteries charge as if they were one large battery. The alternator is none the wiser.

Disimilar types are an issue but on a drive of any decent length both batteries will charge to capacity once they equalise.

The only time this would be any different would be if one or both batteries were knackered.

Anyone who believes differently please back your response up with sound electronic theory. (That does not include websites selling other than solenoid systems.)

Dave

PS. I've no vested interest in solenoid systems and stand to lose or gain nothing defending them. I own a Pirhana and I sell neither.
Thumbs UpThanks 0
Reply 5 of 15
FollowupID: 359567   Submitted: Wednesday, Mar 09, 2005 at 12:03

hl posted:

Hi,

I completely agree. The only possible scenario would be some of the fully sealed batteries that need close to 15V to fully charge them in cyclic use. Unless the isolator also has a voltage step up it won't fully charge. However, in practice there won't be a lot of difference.
I also wonder how some of the relays used in the isolators stand up compared to a starter solenoid type releay.
I have a unit made by GSL and when I opened I could not believe how small the relays are, considering the unit is rated at 100 amps.
So far it is ok, but I do carry a nice jumper cable just in case.
Cheers
Thumbs UpThanks 0
FollowUp 1 of 1
AnswerID: 101669   Submitted: Wednesday, Mar 09, 2005 at 01:16

brett replied:

As most have said that pretty much describes every dual battery isolator on the market. There is nothing magical about the Piranha, pull the lid off and have a look inside, you'll find a couple of relays, or solenoids if you like, that do the switching, there is nothing very technical about Piranha's info, comments like "they are sort of connected in parallel" doesn't really mean much. Ask them what they use to switch the aux battery in and out, relays just like most peoples.
Thumbs UpThanks 0
Reply 6 of 15
FollowupID: 359568   Submitted: Wednesday, Mar 09, 2005 at 12:10

Mad Dog (Australia) posted:

So there are mechanical relays in the Piranha, well blow me down, I thought they were solid state switching
Thumbs UpThanks 0
FollowUp 1 of 1
AnswerID: 101690   Submitted: Wednesday, Mar 09, 2005 at 09:03

drivesafe replied:

Hi folks, there is no problems or drawbacks with using relay type isolators and in the vast majority of situations where used in vehicle situations, relays ( solenoid is just a name used to try and make a relay sound important ) relays actually resolve a lot of problems that would occur when other types of switching device are used in high current switching applications.

You can make most isolators work well ( cheap or expensive types ) by simply using large cable to connect everything up and using large enough cable is by far more important than the type of isolator used.

As for current protection, a circuit breaker will work as well as anything but here is a safety point that many professional installing companies fail to do and that’s to install a second circuit breaker at the other end of the cable, near the second battery, when the second battery is not in the engine bay.

A simple but potentially deadly oversight.
Thumbs UpThanks 0
Reply 7 of 15
AnswerID: 101727   Submitted: Wednesday, Mar 09, 2005 at 12:57

Mainey (WA) replied:

Posted from ‘Bill Darden - battery information’
his statements not mine, placed here only for consideration!

http://www.batteryfaq.org/

#Can I Mix Non-Identical Batteries?
To prevent charging problems when connecting batteries in series, parallel, or series-parallel, do NOT mix old and new batteries or ones of DIFFERENT capacities or types. Mixing old batteries with new batteries is like mixing old milk with new milk, soon you have nothing but old milk. The reason is because you will either undercharge the larger (or newest) of the batteries or overcharge the smaller (or oldest) of the batteries.

#How Do I Increase Battery Capacity?
Two (or more) identical 12-volt batteries can be connected in parallel.
If you connect two 12-volt batteries in parallel and they ARE identical in type, age and capacity, you can more than double you original capacity due to the Peukert Effect.
If you connect two batteries that are NOT the same type or capacity, you will either OVERCHARGE the smaller of the two, or you will UNDERCHARGE the larger of the two.
When connected as exactly shown in the diagrams, the batteries will discharge and charge equally. Between the batteries, cable lengths should be an equal length, short as possible and sized large enough to prevent significant voltage drop of 0.075 volts (75 millivolts) per 100 amps or less in the cables and connectors. Battery cables to the charger or inverter should be an equal length so the batteries will charge or discharge evenly.
What is important is that the battery manufacturer's recommended charging voltages are being applied directly across the battery's terminals from the charging source.

Also;
Collin rivers; Charging Batteries
http://www.caravanandmotorhomebooks.com/

A vehicle charging system, is deliberately designed to drastically cut back charging at 70% of full charge.
The only really safe way to approach 100% charge (90% is a realistic target) is via adequate capacity Solar modules and Solar regulator; or via a 'smart' charger, increasing known as a three-stage charger, these latter chargers are not cheap - they start at $300 or so.

Also as I have asked in a previous reply above;
Does anyone know of someone who has actually changed from an Electronic Isolator to a Solenoid, and is prepared to state the Solenoid recharges the Auxiliary battery system superior to the previous Electronic system ??

As to my own experience, I can state that my 160A/H Deep Cycle battery system is slightly higher voltage at rest than the starter battery, (without the fridge running), that was not the case with the original Solenoid system, hence I changed to the Piranha Electronic system.

Check out your battery system voltage with a digital 'meter', after the batteries have rested for at least 24 hours, compare numbers.
Thumbs UpThanks 0
Reply 8 of 15
FollowupID: 359577   Submitted: Wednesday, Mar 09, 2005 at 13:25

Leroy posted:

Who really cares that much they need to know the intricate ins and outs of batteries? At the end of the day most are only interested in knowing they have a 2nd batt that will supply 12v for their accessories and that it has some sort of charging system. If my 2nd battery is only charging to 80-90% of it's capacity and lasts 2-3 years I'm happy with that. But I won't be sitting up late in bed wondering why that battery didn't last longer or why am I missing out on 10% of it's capacity. At the end of the day it powers my fridge for a few days, the beer's are cold and that's all that really matters......

Leroy
Thumbs UpThanks 0
FollowUp 1 of 7
FollowupID: 359578   Submitted: Wednesday, Mar 09, 2005 at 13:49

Wok posted:

.............................de ja vu
Thumbs UpThanks 0
FollowUp 2 of 7
FollowupID: 359580   Submitted: Wednesday, Mar 09, 2005 at 13:57

Mad Dog (Australia) posted:

>Does anyone know of someone who has actually changed from an >Electronic Isolator to a Solenoid, and is prepared to state the Solenoid >recharges the Auxiliary battery system superior to the previous Electronic >system ?

Bill Darden's FAQ is very good but it does not cover dual battery isolators. His advise covers batteries connected together full time....ie charge and discharge.

Mainey, A solenoid or electronic system are not magic boxes, they are switches. All things being equal...cable sizes, connectors etc, they will charge the same unless there is a higher resistance somewhere.
Thumbs UpThanks 0
FollowUp 3 of 7
FollowupID: 359581   Submitted: Wednesday, Mar 09, 2005 at 14:00

Leroy posted:

switches - that's what I stated right at the topof this post! Beer cooling switches.

Leroy
Thumbs UpThanks 0
FollowUp 4 of 7
FollowupID: 359582   Submitted: Wednesday, Mar 09, 2005 at 14:11

Mad Dog (Australia) posted:

hehe..I've just primed my switch for the weekend
Thumbs UpThanks 0
FollowUp 5 of 7
FollowupID: 359585   Submitted: Wednesday, Mar 09, 2005 at 14:24

Member - Jeff M (WA) posted:

Mad Dog, I can state that my Relay charges my deep cycle better than my old electronic isolater. Absolute fact. Same conditions, .1 volt better at rest.

Mainy:
"A vehicle charging system, is deliberately designed to drastically cut back charging at 70% of full charge.
The only really safe way to approach 100% charge (90% is a realistic target) is via adequate capacity Solar modules and Solar regulator; or via a 'smart' charger, increasing known as a three-stage charger, these latter chargers are not cheap - they start at $300 or so. "

Are you trying to tell me that your Pirahna is a 3 stage charger?? LOL Yeah right, good one. How is your Pirahana going to "boost" the voltage into the batteries (as a 3 stage does). It's only got the same amount of volts to work with as the alternator/regulator is supplying. ie. Your Pirahna cannot supply 14.1 volts @ 30 amps if your regulator is only putting out 13.8v unless its got one big mother switch mode power supply in it (which it doesn't). So the Pirahna has got the same limitation in charging that all the others have, it basically comes down to your regulator and alternator as to what your maximum charge is going to be.

Thumbs UpThanks 0
FollowUp 6 of 7
FollowupID: 359590   Submitted: Wednesday, Mar 09, 2005 at 15:35

hl posted:

Hi,

"#Can I Mix Non-Identical Batteries?
To prevent charging problems when connecting batteries in series, parallel, or series-parallel, do NOT mix old and new batteries or ones of DIFFERENT capacities or types. Mixing old batteries with new batteries is like mixing old milk with new milk, soon you have nothing but old milk. The reason is because you will either undercharge the larger (or newest) of the batteries or overcharge the smaller (or oldest) of the batteries.

#How Do I Increase Battery Capacity?
Two (or more) identical 12-volt batteries can be connected in parallel.
If you connect two 12-volt batteries in parallel and they ARE identical in type, age and capacity, you can more than double you original capacity due to the Peukert Effect.
If you connect two batteries that are NOT the same type or capacity, you will either OVERCHARGE the smaller of the two, or you will UNDERCHARGE the larger of the two."

The whole statement above is marred by the "BS Effect"

This guy does not seem to have the foggiest idea what he is talking about

Please don't qout him anymore.

Cheers

Thumbs UpThanks 0
FollowUp 7 of 7
AnswerID: 101788   Submitted: Wednesday, Mar 09, 2005 at 18:34

drivesafe replied:

Hi Sand Man, have you achieved a better understanding or just created a bigger set of questions to be answered?
Best of luck and cheers
Thumbs UpThanks 0
Reply 9 of 15
FollowupID: 359717   Submitted: Thursday, Mar 10, 2005 at 04:23

Sand Man (SA) posted:

Hmmm! Perhaps you have something there drivesafe.

This has turned into a Yota vs Patrol, BFG vs Cooper, Engel vs Waeco Piranha vs Redarc vs Rotronic theme.
NOT MY INTENT!

Some people obviously don't digest what they read before barging off on a tangent.

The point I was trying to make clear was the danger of a "dumb" dual battery system which simply connects two batteries together in parallel, masking a potential fault to the extent that both batteries could end up cactus and the vehicle (and its occupants) stranded.
Bill


I'm diagonally parked in a parallel Universe!
Thumbs UpThanks 0
FollowUp 1 of 1
AnswerID: 101793   Submitted: Wednesday, Mar 09, 2005 at 19:05

Mainey (WA) replied:

Mad Dog (Australia), Piranha make both solid state systems and also Solenoid systems, they are totally different looking and working systems and you guessed it also different benefits and prices.

******************

The following is an extract from an Email from Redarc CEO regarding the confusion about using a Solenoid charging system and DIFFERENT batteries.

(QUOTE)
From : Anthony Kittel
Subject : RE: isolators
Hello Paul
Sorry for the delay in getting back to you,
In answer to your question:-
In our discussions with a large battery manufacturer it was commented that it is ideal to use two IDENTICAL batteries in a dual battery system and therefore we pass that information on to our customers.

We are updating our website and we will remove the confusion. (end quote)

******************

Hl, posted, (Quote)This guy does not seem to have the foggiest idea what he is talking about
please don't quote him anymore(end quote). ‘Bill Darden - battery information’ I believe is relied upon for relevant information..

******************

Jeff M (WA), Collin Rivers made the following statement – Not me!

(Quote)"A vehicle charging system, is deliberately designed to drastically cut back charging at 70% of full charge.
The only really safe way to approach 100% charge (90% is a realistic target) is via adequate capacity Solar modules and Solar regulator; or via a 'smart' charger, increasing known as a three-stage charger, these latter chargers are not cheap - they start at $300 or so. "(end quote) and I don’t believe he is suggesting that a Piranha is a 3 stage charger.

Jeff (Quote)##¡K¡K.NO..... I really didn't think so ƒº "
I think it was unwise for you to assume this, because I am not person you didn't think existed.(end quote)
Could I ask what went wrong with your Electronic system and what brand and model was it?

****************

As I stated I have had three different isolators on the same vehicle and battery system, I did not replace any system because it failed, I upgraded each time as I required the extra voltage, the last 10% obtainable is important

Is a hornets nest here now, everyone has an opinion,
you often learn from the mistakes of others!
Thumbs UpThanks 0
Reply 10 of 15
AnswerID: 101813   Submitted: Wednesday, Mar 09, 2005 at 20:08

Mal Vercourt WA replied:

only a fool or a sucker would fit a piranha or any other electronic battery isolator
if you want a quality bit of kip that works as it should then dont mess around with rubbish electronic isolators
in WA we fit rugged stuff what functions and does the job properly
fit a Redarc CP12V http://www.redarc.com.au/sbi.htm
if you can find another battery isolator that functions better than a Redarc buy it
Thumbs UpThanks 0
Reply 11 of 15
FollowupID: 359671   Submitted: Wednesday, Mar 09, 2005 at 21:51

drivesafe posted:

Hi Mal Vercourt WA, that’s a bit unfair to call someone a fool or sucker for fitting that brand.

In many cases, the people who have them fitted, have no knowledge of what is good and what is not and usually fit them on the recommendation of businesses that consider the bigger profit a good reason for pedalling them or just don’t care what they are selling.
Just reading through this posting, one can get an idea of how much fact and fiction is floating around about these types of devices, so it’s a bit rich to expect the average joe to have a better knowledge of the same devices.
Cheers
Thumbs UpThanks 0
FollowUp 1 of 4
FollowupID: 359690   Submitted: Wednesday, Mar 09, 2005 at 22:43

brett posted:

Yeah wouldn't call them a fool, nothing wrong with the Piranha, I just think they make their isolators sound like they do a bit more than the others when actually they work the same way
Thumbs UpThanks 0
FollowUp 2 of 4
FollowupID: 359698   Submitted: Wednesday, Mar 09, 2005 at 22:52

Member - Jimbo (VIC) posted:

Drivesafe,

Mal is just Ozi wearing another costume.

He'll be gone soon, that is until he appears again under another alias.

Cheers,

Jim.
Thumbs UpThanks 0
FollowUp 3 of 4
FollowupID: 359709   Submitted: Wednesday, Mar 09, 2005 at 23:15

drivesafe posted:

Thanks Jimbo, I’ll ignore him.
Thumbs UpThanks 0
FollowUp 4 of 4
AnswerID: 101854   Submitted: Wednesday, Mar 09, 2005 at 22:40

brett replied:

Another important point is a lot of the theory behind a battery only being able to be charged to 80% has been around a long time, older cars had their regulator set to around 13.8 to 14V. Most modern cars have the regulator set to 14.4V which is about the same as your fancy 3 stage charger which will apparently charge to 100%, so there is really no reason why your alternator can't do the same, the only limiting factor is time, it takes a while to get that last 10% in, maybe 10 hours of float charge, unless your driving for 10 hours it is difficult but I wouldn't say impossible.
Thumbs UpThanks 0
Reply 12 of 15
FollowupID: 359694   Submitted: Wednesday, Mar 09, 2005 at 22:47

Mad Dog (Australia) posted:

My old Lux does 14.4 and after a while somehow drops back to 13.8, not sure how it does that though.
Thumbs UpThanks 0
FollowUp 1 of 3
FollowupID: 359702   Submitted: Wednesday, Mar 09, 2005 at 23:02

brett posted:

How old is your 'old lux'? from what i've seen it was around mid 90's that the higher voltage become popular. It probably drops due to temperature compensation in the regultor to limit the amount of gassing the battery does, as a higher voltage at high temp will cause the battery to gas.
Thumbs UpThanks 0
FollowUp 2 of 3
FollowupID: 359712   Submitted: Wednesday, Mar 09, 2005 at 23:34

Mad Dog (Australia) posted:

Late 93 Brett so yeah it must be temp compensated...thanks
Thumbs UpThanks 0
FollowUp 3 of 3
EOTopo - revised & updated roads/tracks Sponsor Message
New Australian topographic map for whole of Australia at 200K. Contains nearly 5000 updated roads/highways representing a significant improvement over the old NATMAP Topo250K data. Suits most devices.
www.ExplorOz.com/EOTopo
AnswerID: 101904   Submitted: Thursday, Mar 10, 2005 at 10:38

Mainey (WA) replied:

Some INTERESTING reading, for those without a closed mind, based on information freely available from the web that is (believed) to be factual...

Did you know?
• Car cranking batteries are NOT designed for cycling, and will perform very poorly and fail early if used for this purpose, this is a fact, it’s the old horses for courses and oils ain’t oils.
• On the other hand Deep Cycle batteries ARE designed for cycling, but should NOT be cycled below 50% of their capacity if you want them to last for many years.
• Standard car and truck alternators are designed for various reasons to recharge CAR batteries to 70-80%, and this works very well, until it comes to charging storage batteries where you need as much capacity as possible, also batteries can take 8-12 hours of continuous engine running to achieve this 70-80% charge.
• Automotive battery chargers suffer from the same less than perfect regulation as car alternators, and achieve much the same results, for a full and deep charge, 3 stage smart chargers are required. A quality SOLAR system will also give a full and deep charge.
• Auxiliary batteries that are mounted some distance away from the main battery (like in a caravan), MUST have very heavy connecting cable (minimum 13.5 mm² 6 B&S), or you will achieve much less than 70% charge, often less than 50%!
A bit about Alternators.

#Standard car and truck alternators are designed, for various good reasons to recharge CAR batteries to only 70-80%, and this works very well for normal cars and trucks, but when it comes to charging our storage batteries, where of course we need as full a charge as possible, that same 70-80% is not very helpful at all.

#Standard alternators are designed primarily to top up quickly the surprisingly SMALL amount of energy that is removed from the battery by the starter motor on engine start up! Then to keep up with all your accessories, radios, head lights etc.

#They were never designed to recharge deeply discharged batteries, and they fall short in this area unless modified or replaced with a specialized charging alternator, and smart multi stage regulator.

****************************

Yes, this information is copied and is not my own words -
so don't tell me I am wrong, as I am only the messenger.
If you believe this information is wrong, please _explain_ why it is wrong!

Please post factual evidence to the contrary of the above!

We all want to learn the truth, and if you believe you know better, then now is your opportunity shine and to present those facts backed up by your evidence, lets leave personal opinions as just that, opinions… lets stick to the facts!
Thumbs UpThanks 0
Reply 13 of 15
FollowupID: 359752   Submitted: Thursday, Mar 10, 2005 at 10:58

Mad Dog (Australia) posted:

Instead of moving the goal posts why don't you address some of the issues above dealing with isolators.
Thumbs UpThanks 0
FollowUp 1 of 8
FollowupID: 359753   Submitted: Thursday, Mar 10, 2005 at 11:20

Leroy posted:

Mainey likes to regurgitate this stuff on the Overlander forums also.....

Why believe everything you read Mainey?
Why leave it up to others to provide factual evidence contrary to what you regurgitate??
This is a forum and is full of opinions! That's what makes it a forum. Everyone is entiltled to THIER opinion.
If you want facts then you should run some experients with all your different isolators, all the different types of batteries there are and post the results. Then you also would have some FACTS to post!!

Leroy
Thumbs UpThanks 0
FollowUp 2 of 8
FollowupID: 359851   Submitted: Friday, Mar 11, 2005 at 10:27

Mainey (WA) posted:

Mad Dog,
Put simply, if I posted “I originally used a Solenoid and was not happy with the battery performance so I changed to a Piranha system”, WITHOUT, giving logical reasoning, you then have only another opinion, and not a justifiable experience.
It is the equivalent of a guy who condemns the idea of flying to the moon, because he has not been there and does not believe it is possible, I have posted from my own life experience, actually based on fact not on opinions or fiction.

Leroy,
I have read your post above and am amazed at your inability to understand the English language, let alone spell the words, you say I ‘regurgitate this stuff on the OL forum’.... please post the link to prove your point!
As to 'you believe everything I read', well, I only believe what I understand to be factual and true, why don't you please show me the error of my ways, and you post relevant information you believe will dispute anything I have read (and copied) and posted on the forum, as I am prepared to read what you believe is not true from either of the web sites I plagiarised to post here, and I am sure they are also interested in your reply.

You must believe the CEO of Redarc when he has emailed me with relevant information that their system does actually work superlative with identical batteries however NOT different batteries, and that he will also make their web site more explicitly accurate in its product information, his idea not mine.

You say I should 'run some experiments' ….don't you think I have already done that? you think about it and ask yourself why would anyone spend money and change from a solenoid to an electronic system, IF it could be shown the solenoid was working as good as an Electronic system, and then why spend even more money and change to the Rotronics system, more than twice the price again, IF there was no further distinct advantage...?

The answer is very simple....... Yes, I have tested the three systems!!!

Obviously you have not, and please remember, I use a dual battery system comprising of; 700CCA start battery and 160A/H Calcium Deep Cycle battery system, not two identical Start batteries, and I am simply not prepared to have a good, but still not best system installed when I can simply (for money) have a superior isolator system !!
Thumbs UpThanks 0
FollowUp 3 of 8
FollowupID: 359858   Submitted: Friday, Mar 11, 2005 at 11:36

Leroy posted:

I'm glad you're amazed. So you use a spelling checker? Well ol' boy that's one up on me! I still struggle with this crazy english language.

No need to post links to your posts in the Technical area on the Overlander Forum as people can do a search if they are really that interested.

I have already stated my opinion in a reply further up the post. And if you have tested all 3 systems where are all the results?
I'm sure the thousands of people with Redarcs,ARB,Piranah whatever with their dissimilar bateries, if they were having so many problems it would be reported here.

Leroy
Thumbs UpThanks 0
FollowUp 4 of 8
FollowupID: 359864   Submitted: Friday, Mar 11, 2005 at 12:30

Mainey (WA) posted:

Leroy,

(Quote)
(A) If you have tested all 3 systems where are all the results?
(B) I'm sure the thousands of people with Redarcs,ARB,Piranah whatever with their dissimilar bateries, if they were having so many problems it would be reported here(end quote)

(a) The results are in the “fact” that I did have a solenoid and actually replaced it with a Piranha system, and then replaced that with a Rotronics system.
I recently advertised the Piranha system on the 'for sale' on the other forum!
Please advise me what more proof you require???

(b) Fact is most would not even know they are having problems till the battery dies, read how many die at a tender young age, with so little work and get the idea for yourself, it is not the batteries fault, generally it is the lack of recharging!

How many people admit here that they can’t afford a Rotronics system?
How many state they bought a solenoid system because they saved money?
How many state they only get a few years life from their battery?
Then read the email to me from Redarc, it explains it in very simple English.

As I have stated previously; a solenoid system definitely DOES have a place as a battery isolation device, and I reiterate and as Redarc also claim, ONLY when the two batteries are identical – my battery system is not compatible with their solenoid system simply because I use Deep Cycle batteries, not two identical Starter batteries!

Hope this assists you to understand....
Thumbs UpThanks 0
FollowUp 5 of 8
FollowupID: 359868   Submitted: Friday, Mar 11, 2005 at 13:50

Leroy posted:

I've understood along. What I don't understand is the way you try to make people understand what you think you understand.

I'm glad what you have installed is good for you, the same as what others have installed is good for them (and me). I could install 3 differnt branded isolators in 7 years also. Doesn't prove one works any better than the other.

Fact - lot of people don't relise they have a problem with thier battery until their car doesn't start either!

Zzzzzz.....sorry for my poor english

Leroy
Thumbs UpThanks 0
FollowUp 6 of 8
FollowupID: 359875   Submitted: Friday, Mar 11, 2005 at 14:18

drivesafe posted:

Mainey, sorry mate but I have to pick you up here.
Your latest posting you state that Redarc said ONLY identical batteries while in your original posting it stated IDEALLY recommend using identical batteries. There is a world of difference and for a fact, when using a relay based system it is most unlikely that you will have problems when using unlike batteries. FACT.
Thumbs UpThanks 0
FollowUp 7 of 8
FollowupID: 359899   Submitted: Friday, Mar 11, 2005 at 18:37

Mainey (WA) posted:

drivesafe, this is redarcs reply email to me,

(Quote)Sorry for the delay in getting back to you,
In answer to your question:-
In our discussions with a large battery manufacturer it was commented that it is ideal to use two IDENTICAL batteries in a dual battery system and therefore we pass that information on to our customers (end quote)

Question--> what is the information they pass on;
is it, you can use a Deep Cycle battery and a Crank battery?

No, the information they pass on is to use identical batteries!

When I am advised by the ceo of redarc; it is "ideal to use two identical batteries" when I have asked him "can I use two different batteries", I understand that to say to use other than, two identical batteries is not their first choice or could I say it another way and say it is not their recommendation?
Yes, it is a play on words but the email reply does not state to use different batteries, it does specify 'identical' batteries.
Sure, maybe you can use two different batteries, and you can use thinner wiring looms, they both will work to some degree, but not as efficiently as the manufacturers specification and recommendation.
Another point is they say basically the same words in their technical specifications sheet included with each solenoid.

Leroy,
A faulty car battery in not pertinent, as it is charged direct by the alternator, the solenoid/isolator only functioning once the car battery has reached its fully charged voltage, unless there is a fault in the system.
Thumbs UpThanks 0
FollowUp 8 of 8
AnswerID: 101914   Submitted: Thursday, Mar 10, 2005 at 11:38

Nebster replied:

Did anyone call a Fire Truck?

Ah well that looks like the search engines will list yet another dual battery discussion gone pear shape.

hahahahahaha

my momma told me to never argue with a fool
they'll drag you down to their level and then beat you with their experience.
Thumbs UpThanks 0
Reply 14 of 15
FollowupID: 359860   Submitted: Friday, Mar 11, 2005 at 11:58

Mainey (WA) posted:

(Quote)Sand Man (SA) posted "Voltage Sensing Battery Isolators"(end quote)

Nebster, you state; “another dual battery discussion”

I was of the opinion it was about Battery Isolation techniques !!
But then maybe your momma is right! you obviously meant UP to their level and also UP to their experience... L0L

Don't be offended, you have read this thread and don’t know what it is about!
Thumbs UpThanks 0
FollowUp 1 of 1
AnswerID: 102041   Submitted: Friday, Mar 11, 2005 at 09:15

drivesafe replied:

For all the carrying on about which isolators and there affect on the batteries, try looking at actual battery usage and the affect of this usage has on the over all life of the battery.

If you look at specs of most brands, they will list how many charges you can get from a given battery if it is taken to a given discharge level.

The following is a VERY rough idea of what you can expect.

Lets say that if you have brand X and they state that you will only get 50 charge cycles out of that battery if you take it down to say 20% and you go camping every weekend, and you take it to 20% every time you use it.
It would be pretty safe to say that it will only last a year.

But if you are like most people and only do the weekend bash once a month, even punishing the battery like this, you should still get 4 years use out of the battery.

Now before you go jumping up and down, yes there are a lot more factors that have to be conceded.

The point I’m trying to make here is that the way you use the battery will have as much, if not more of an effect on the battery’s life span as will the way you charge it and the way the battery is going to be used, should be the deciding factor in how you set-up a Dual Battery System.
Cheers
Thumbs UpThanks 0
Reply 15 of 15
FollowupID: 359857   Submitted: Friday, Mar 11, 2005 at 11:27

Mainey (WA) posted:

DS,
That is true, however, what is good for the weekend warrior (camper) is generally not good enough for us old grey nomads who spend months camped in the one spot, generally on an idyllic beach with the blue ocean at the front door....
We need reliable, efficient battery power available constantly
-> without having to lift a finger to make it happen.

Any solenoid (or switching system) would be good for a few weeks holiday or with daily driving, however long term camping in isolated areas has vastly different requirements and unfortunately constant driving around or leaving the vehicle running to recharge the battery, is not my own idea of a holiday.

For a round Aussie holiday that was supposed to last only 12 months, (some years ago) a Solenoid system with a large DC battery was originally installed back in 1997, and a few months later I was advised to replace the Solenoid. 1998 I added a Solar panel, 2001 I changed the batteries, 2005 I again changed the Isolator.

You learn from the experience and also the mistakes of others!

But what would I know, I only have to completely rely on my battery system on a undeviating basis 24/7, the weekend campers can go back home on Sunday nite to a house with a fridge full of food, TV and a cold beer, LoL.
Thumbs UpThanks 0
FollowUp 1 of 2
FollowupID: 359876   Submitted: Friday, Mar 11, 2005 at 14:32

drivesafe posted:

Mainey, you are working from one users point of view and you have me in part, in that the vast majority of my customers are weekend worriers but we have also supplied more that 2,000 motor homes with dual battery charge controllers and a large number of these do camp for long periods of time and when you consider the fact that we get only 1 in about 200 ever being returned and to date have not heard of any of the motor homes have any problems recharging there systems no matter what the use. So to say relays ( solenoids ) won’t do the job is just pure fantasy.
Thumbs UpThanks 0
FollowUp 2 of 2