WHAT IS KILLING MY AGM BATTERIES?

Submitted: Friday, Oct 31, 2014 at 07:05
ThreadID: 109997 Views:11199 Replies:15 FollowUps:38
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After changing my century deep cycle AGM batteries 2 times in 12 months looking for possible causes.

Here are some facts.

2 x 105 AMP Deep cycle in paralell.

I didn't deep discarge more than twice. Mostly 10 or 30% max. before dieing.
Most of time on charger - Projecta 7 stage intelligent 10Amp charger.
Nevara - Relay linked to starter battery.
Both times they died after driving more than 4 - 5 days 6 hrs long distances.
Solar panels 400 Watt charges upto 20 Amps for 12V fridge
Fridge current draw - 12 Hours = 6 to 8 Amps over night.

TV / Antenna - with geni or on "invertor" only 3 hours absolute max ever a few times. TV energy rating 4.5 stars it's a small TV.
Water pump - 5 to 9 amps.

NO SHORTS OR LEAKS - Reading with nothing running 0.1 Amp!

One morning I awake seeing regulator alarm had gone off WHAT THE!
The solar regulator had cut off the power at 11.4V the setting I have programed not to wreck the batteries!
Also reading a use of 25Amps of and battery Voltage minium of 8.8V that night.

POSSIBLE CAUSES
1. Batteries
2. Charger
3. Relay
4. Solar regulator
5. Over use - I am ruling that out knowing full well they have had little use.

Could 2, 3 or 4 be overcharging batteries?
2. Charger is only 10Amps but batteries are quickly full, with little use.
3. Relay - Nevara charges upto 16v my vans Altinator 30Amps. Merc sprinter. I have seen 15V in display.
4. Solar is a Plasmatronic Dingo 40/40

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Reply By: Slow one - Friday, Oct 31, 2014 at 07:20

Friday, Oct 31, 2014 at 07:20
jat,
Another possible cause. Is the battery under the bonnet as AGM batteries don't like heat.
AnswerID: 541101

Follow Up By: jat g - Saturday, Nov 01, 2014 at 07:50

Saturday, Nov 01, 2014 at 07:50
It hasn't been hot and it's not under the bonnet. So we can rule that out.
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Reply By: Ross M - Friday, Oct 31, 2014 at 07:33

Friday, Oct 31, 2014 at 07:33
What sort of 12v fridge is it?
If a 3 way type then that will kill anything.

Where are the batteries situated. If under bonnet ie in HOT zone, the heat may be killing them.

Is all the cabling correct/suitably sized to allow for the batteries to actually get fully charged?

Are the battery terminals CLEAN and a good connection with the cable lugs,clamps?

Is the relay actually disconnecting the main battery?

Is the alternator faulty ie, one diode sick.
It is hard to believe the alternator is only 30 amps output. A 90 amp alternator with a blown diode, ie, an open circuit diode, immediately reduces the alternator output to 1/3 of it' total output, so a 30 amp maximum charge would indicate a 90 amp alternator ( which is what I would expect it to have) really does have a DUD diode and that may be contributing to your problem. If a Valeo alt then it is even more highly likely.

Just a few things to ponder. It may point you in the right direction.
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Follow Up By: jat g - Saturday, Nov 01, 2014 at 07:42

Saturday, Nov 01, 2014 at 07:42
Reading up on ECU chips. Which control newer vehicles alternator output under the Euro standard.
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Reply By: olcoolone - Friday, Oct 31, 2014 at 08:13

Friday, Oct 31, 2014 at 08:13
Have you batteries "died" as in stuffed and can't be revived...... or are they flat flat flat.

1) What have you done to determine the above.

2) Have you had the batteries charged at a place like a a battery place, auto elec or local mechanic to see if they can charge them OK.

The chances of having multiple failures in a short period of time is odd.

Who installed all your aux battery gear?

AnswerID: 541103

Follow Up By: jat g - Saturday, Nov 01, 2014 at 07:49

Saturday, Nov 01, 2014 at 07:49
All done by myself. The battery I gave up was tested - had a capacity of only 25Amps. I still have the second one and will do a discharge tests on it. It holds the Voltage well still 13.1V.
Now I have a charger with a reconditioning mode so will give that a go to. We shall see!
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Follow Up By: olcoolone - Saturday, Nov 01, 2014 at 08:36

Saturday, Nov 01, 2014 at 08:36
If you are destroying batteries there is something wrong with what you have done, get it checked out by someone in the know.

Many are jumping to conclusions and with out looking at the setup the information could be misleading and lead you on a bumsteer.

You should get the advice needed as every one on here is a battery and charging expert.
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Follow Up By: jat g - Saturday, Nov 08, 2014 at 07:35

Saturday, Nov 08, 2014 at 07:35
Did a recondition of that battery. Got 25Amps out just the same with no improvement.
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Reply By: Member - Serendipity(WA) - Friday, Oct 31, 2014 at 09:47

Friday, Oct 31, 2014 at 09:47
I have a camper on the back of my landcruiser so might be similar setup. In the camper I have 2 x agm batteries and suffered a similar problem with them going flat. How I fix this problem now is to...

1. Change all the leads to accessories like fridges to 6mm2 leads. Cost a bit but worth it.- ordered the cable from ABR Sidewinder who is a forum business member.
2. Bought a DC to DC charger - made all the difference for the charge coming from the car and the Solar panels. The voltage drop from alternator to camper batteries seemed to be enough to effect the charging. This was probably the biggest one.
3. Bought a 'charging chip' which goes inline to the car alternator and ups the car charge from 13.4 to 13.9. It seems new cars deliberately have a lower volt charge to help with ??? economy, pollution control ... who knows what. This also seem to help especially with the under bonnet dual battery system which is separate to the the camper 2 x batteries. (so I have 4 x batteries all up)

Before I could barely last 3 days before I had flat batteries. Now I have been 4 weeks on the road and not a problem. Also I got rid of the Waeco fridges. They draw a lot.

Cheers

Serendipity



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AnswerID: 541114

Follow Up By: jat g - Saturday, Nov 01, 2014 at 08:01

Saturday, Nov 01, 2014 at 08:01
DC DC charger looks like the next hole in my pocket. - Appriecate your info very much.
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Reply By: HKB Electronics - Friday, Oct 31, 2014 at 11:09

Friday, Oct 31, 2014 at 11:09
"3. Relay - Nevara charges upto 16v my vans Altinator 30Amps. Merc sprinter. I have seen 15V in display."

What was the ambient temperatures when you noted those voltages, those are quite high charge voltages and I would only expect to see those out of an alternator in a very cool climate. You wrote the batteries died after 5 to 6 days of 6 hours duration drive times, if the ambient temperature was above 15C I wouldn't be surprised at all that the batteries died.

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Follow Up By: Gronk - Friday, Oct 31, 2014 at 11:19

Friday, Oct 31, 2014 at 11:19
Very observant ......and you are probably right..

I have a booster diode in my 200 series ( from you know who ! ) and mostly see around 14 V but very occasionally it will creep up to 14.8 for very short periods, so 15 or more is definitely something to be alarmed about..
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Follow Up By: HKB Electronics - Friday, Oct 31, 2014 at 11:59

Friday, Oct 31, 2014 at 11:59
Voltage shouldn't get that high except under very cold conditions, could be the alternator voltage regulator or the booster diode, could also be a dirty connector etc, could try giving the plug on the alternator a spray with some CRC and insert it in and out a few times especially if the alternator has had a dunking or mud bath.

Same for the sensing fuse a small amount of cleaning fluid and insert the fuse a couple of times to clean the contacts.

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Follow Up By: Gronk - Friday, Oct 31, 2014 at 21:50

Friday, Oct 31, 2014 at 21:50
whats your thoughts on what the max voltage should be in a 200 series ?

Mine sits between 14 and 14.3 V most of the time....it's only the occasional spike up to 14.8 that worries me.
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Follow Up By: jat g - Saturday, Nov 01, 2014 at 07:55

Saturday, Nov 01, 2014 at 07:55
Want to thank all you guys for bringing this to my utmost attention. Now woth full priority.
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Reply By: Member - Stuart and Gunny - Friday, Oct 31, 2014 at 11:12

Friday, Oct 31, 2014 at 11:12
Hi Jat G
A few things to check.
1)Alternator voltage at car batt then house batts.
2)Is the wiring heavy enough from the alternator to the house batts?
3)Is the alternator seeing the house batts?(a problem with modern electronic alternators)
4)Your batt charger is under powered to charge your battery pack.Even know on the box it says it is in its range that is crap.The rule of thumb is what ever your battery capacity your charger should be at least 10% of your battery pack.EG 2x105amp batts=210amps.Minuim size charger 20-25 amps.Your battery charger must be in a well ventelated area,preferrably cool as to not over heat.The hotter your charger gets it lowers its out put to protect its self from over heating.
5).1 of an amp with nothing working is standard.
If i had to stab in the dark i would guess your under powered charger is the problem.A 10amp charger trying to charge 210 amp battery pack would be working its ring off.So it would get hot pretty quick and then lower its out put to protect its self so your batterys would never be fully charged.
Good luck with your problem.
AnswerID: 541125

Follow Up By: jat g - Saturday, Nov 01, 2014 at 07:58

Saturday, Nov 01, 2014 at 07:58
Just installed IC2500 projecta 25Amp 7 stage. So hopefully we can dismiss that possible cause.
Thanks for your valuable info.
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Reply By: Zippo - Friday, Oct 31, 2014 at 13:09

Friday, Oct 31, 2014 at 13:09
Low voltage cutoff/alarm in the morning shows that the battery available capacity wasn't adequate to meet the overnight discharge. Just analyse that for a moment. Either more load than you thought or under-charged to start with.

Reading (presumed the max) of 25A load? Where is it going? The fridge? Is that "6 to 8 Amps" really Amps or Amp-hours? Is it a 3-way? If so, the current draw on DC is CONTINUOUS. Scary!

The solar charger - are you sure (i.e. have you checked) that there is no discharge through it after sundown? Does the solar reg interfere with other charging methods? How is it interfaced to the rest of the system?

Alternator 30A - is that for real? Nameplate or measured? (In 1970 I had a small Fiat which had a 55A unit). If that's what the nameplate - or manufacturer - states then chuck it away quick smart and get a real one. If measured, it definitely sounds faulty and that would tie in with failure after several "long-enough" driving days.

The "relay" used to parallel the AGM's with the cranking battery and alternator - has it been tested? Where are the AGM's located? What does the manufacturer recommend as a charge regime and in particular the float voltage?

Two sets in that time says clearly there is a problem in your arrangement. It *could* be overcharging, or it could be under-charging. But until you are able to monitor voltage with some precision at the AGM's while on the road the picture will not become clear. (I'm unable to include a pic of my setup but it is an accurate voltmeter with a selector switch mounted under-dash so I can monitor main or aux battery voltage on-road to 10mV resolution. That would allow quick determination of over-charge or under-charge and whether the parallelling relay/device is functioning properly). Either that or MEASURE (not estimate or "calculate") current in various parts of the system to see what is flowing where.

Some time ago I invested $50 in a Chinese tong-type meter with DC current capability (many don't have that feature) including a 40A max scale. That has come in handy in sorting several other vehicles' issues. While any competent auto-sparky could sort your system, there is a feeling of satisfaction doing it yourself with guidance, as well as $$$ to be saved.
AnswerID: 541129

Follow Up By: jat g - Saturday, Nov 01, 2014 at 08:08

Saturday, Nov 01, 2014 at 08:08
I sort of answered this below in one faul sweep. Just getting use to this forum. Have taken all in, most of which is not as bad as you might of concluded though. Measuring the voltage now is the AC DC charger and the solar panel regulator. Will let the Auto electrica do the rest Wednesday.
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Reply By: Member - Phil G (SA) - Friday, Oct 31, 2014 at 13:30

Friday, Oct 31, 2014 at 13:30
Your Century AGM batteries have a maximum initial charge current of around 25 amps.
Your Mercedes Alternator is actually between 115A and 150A max current.
Your regulated voltage is high at 15V.
Put those three things together and you have dried out your AGMs by exceeding the allowed charge current. Little wonder they died.

By using a simple relay as an isolator, so you are delivering full voltage and unrestricted current to the AGM batteries.

You need a device to limit the charge current to those batteries. A 20A DC-DC charger would do the trick. With 2 batteries, maybe a 30A, but I wouldn't use a 40A.
AnswerID: 541131

Follow Up By: Member - Phil G (SA) - Friday, Oct 31, 2014 at 13:35

Friday, Oct 31, 2014 at 13:35
Just found a link to the Century specs and your max charge current is 30A for your 105Ah batteries, and 15V is too much. I had the same issue some years back. I measured up to 50A going from a Landcruiser alternator into a 105Ah AGM which is why it died.
I expect your Mercedes is regulated for high Calcium batteries.
http://www.centurybatteries.com.au/content/documents/deep-cycle/dc-agm-c12-105da.pdf
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Follow Up By: jat g - Saturday, Nov 01, 2014 at 07:32

Saturday, Nov 01, 2014 at 07:32
I read that the Nevara charges upto 16V!!!! No wonder. Well thanks a lot Mr salesman for selling me that.
I just added a post below apparently the ECU chips on newer vehicles make it diffecult to match the right DC DC charger, now Redarc have different chargers for the varing ECU CHIPS and call them BCDC chargers.
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Follow Up By: jat g - Saturday, Nov 01, 2014 at 08:10

Saturday, Nov 01, 2014 at 08:10
Thanks for that info am now looking into DC DC charger.
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Follow Up By: Member - Phil G (SA) - Saturday, Nov 01, 2014 at 11:23

Saturday, Nov 01, 2014 at 11:23
Jat,
Any chance you can tell us what a "Nevara" is? Or a link?
I couldn't find it with google and have assumed it was a relay because that's what you said.
And just to reinforce with you that I believe the primary problem is that you have too many amps recharging your aux batteries from the alternator. It is made worse by high regulated voltage, but simply dropping that voltage will not fix your problem. You must restrict current to a level below the 30A max specified by the battery manufacturer.
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Follow Up By: Allan B (Member, SunCoast) - Saturday, Nov 01, 2014 at 11:41

Saturday, Nov 01, 2014 at 11:41
Phil, he may mean "Narva".
Cheers
Allan

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Follow Up By: jat g - Saturday, Nov 01, 2014 at 12:14

Saturday, Nov 01, 2014 at 12:14
Narva 61092BL 160A peak cutin 13.3v cutout 12.7v Reading that batteries of different voltages can not be used.
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Follow Up By: Member - Phil G (SA) - Saturday, Nov 01, 2014 at 12:22

Saturday, Nov 01, 2014 at 12:22
Thanks Jat. Its a good bit of gear - a voltage sensitive relay that lets full voltage and current through from the alternator.
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Follow Up By: Member - Phil G (SA) - Saturday, Nov 01, 2014 at 12:29

Saturday, Nov 01, 2014 at 12:29
I mean it's a good bit of gear, but not good for your vehicle or AGM batteries with a current restriction. Your other option is to change to an AGM battery which doesn't have a current restriction (eg Optima).
I'm still a bit surprised you've measured 15V on your Merc.
Are you sure the multimeter is OK? - sometimes they measure high when their internal battery is going flat.
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Reply By: Ron N - Friday, Oct 31, 2014 at 14:12

Friday, Oct 31, 2014 at 14:12
I've got a number of top-of-the-wozza Exide calcium batteries (they come with 48 mth warranty), Marshall "commercial 4x4" batteries, and Supercharge Gold batteries - and every one of them has a decal on top, that clearly states "MAXIMUM CHARGE VOLTAGE - 14.8V".

I think you need to do something about ensuring the voltage output of your alternators is limited to 14.8V.

The advice about poor electrical contacts creating resistance and thus raising voltage is crucial advice.
Check that often-overlooked very important item - the earth strap between body and engine - for cleanliness and security of contacts.

Cheers, Ron.
AnswerID: 541134

Follow Up By: jat g - Saturday, Nov 01, 2014 at 07:39

Saturday, Nov 01, 2014 at 07:39
Alternator input. Yep I think that could also be part of the problem or is the problem. Am disconnecting it looking into DCDC charger.
Contacts checked clean secure (tight)
Thanks for your input.
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Reply By: The Bantam - Friday, Oct 31, 2014 at 14:14

Friday, Oct 31, 2014 at 14:14
Now to summarise.

Maximum initial charge rate not limited to keep within spec.
Charge voltage too high.
Temperature may be a factor....everything about every battery suffers above 25C.
Overnight current draw may be more than visioned and thus cycle depth deeper than expected.

All of the above will cause some deteroiration over time, resulting in reduced capacity.

Reduced capacity..more vunerable battery.


NOW
because you have two batteries in paralell.

Identical batteries..good

BUT..exactly how are they wired.

Do the main connection cables both come to one battery and then paralelled to the second?
If so this can cause one battery to work harder than the other......it may only seem to be a small extra resistance...but it can make a big difference.

Best to wire the batteries in paralell as usual..then connect the positive lead to one battery and the negative lead to the other.

What can happen is one battery is stressed and fails and takes the other with it.

Not saying this is the whole cause but it is a proven problem in paralelled batteries...

All of the issues mentiond may not be a cause on their own......but compounded they may be spelling rapid death.

Un when you replace your batteries....um maybe not Century and maybe not AGM.

cheers
AnswerID: 541135

Reply By: jat g - Friday, Oct 31, 2014 at 17:06

Friday, Oct 31, 2014 at 17:06
Wow thats a lot to think about. Lets see if I can cover most questions here even with alzeheimia brain waves.

Batteries are inside car not under bonnet.

Solar reg. has Tempurature sensor direct on bat. Displays in the 6 months round 18 deg. night colder down to 5 occasionaly.

Batteries show no sign of heat.
2 Batteries are wired - Neg to neg and pos to positive. A 100Amp cable which seems tiny to me but battery world meant it was totaly fine as batteries are only 15cm away.

My saying the Alternator was charging to 30Amps - was quoted to me by RV builder. BEEP! Wrong. Thanks.

Nevara relay connection wire is about 1cm thick brass, its dam thick and only 1\2 a meter away from starter battery which is located also in the car under passanger side floor.

Monitored via Multi meter direct on battery and on solar regulator display (Same reading)
All wire thicknesses are adiquate to accessories. I was very pedantic about that when building.

Fridge is a not 3 way. 12V compressor fridge - Draws up to 7 Amps whilst cooling only a few minutes at time, not per hour! Over 12 hours it will draw a "total"of 8 Amps (seen as load on display of solar regulator) not Amp hours.

1. I have booked it into Auto electrician wednesday. I will definatly get him to see what we can do regarding regulating voltage from Alternator and have him test it along with Nevara relay.

2. Just upgraded Charger to a projecta IC2500 with built in tempurature sensor today "TICK"

3. Also will disconect NEVARA before driving anywhere. If sunny 20amp solar panels do the job well.

After driving battery charger stopped charging when plugged into 240V quite quickly.
Is it ok to have solar regulator on all the time? Do batteries prefer rest time?

Hope I've covered most of it.

Thanks you all for your answers, your all really great. This would have to be the best forum!! I like U.















AnswerID: 541140

Follow Up By: The Bantam - Saturday, Nov 01, 2014 at 10:07

Saturday, Nov 01, 2014 at 10:07
One important question.

do you have the solar regulator and another source of charge connected at the same time.

If you have two or more sources of charge connected at the same time.......If so one regulator could be confusing the other.

go back upp the thread and read carefully what I posted about how the batteries are conneced in paralell and to the supply cables.

I am no great advocate of DC to DC chargers....BUT

In this situation I strongly recommend installing one of the multiple input DC to DC chargers.

Cteck, redarc and others offer these.

They will take you alternator, solar and battery charger inputs and output the best it can make of all three AND limit the maximum initial charge rate.....including MPPT solar regulation.

cheers
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Reply By: Tim F3 - Friday, Oct 31, 2014 at 17:56

Friday, Oct 31, 2014 at 17:56
My son is a mechanic for Mercedes , he advised that he often replaces batteries at around 6 months on newer models due to their smart charging system not charging the original battery correctly. How old is your vehicle ????
Just a thought...
AnswerID: 541142

Follow Up By: jat g - Friday, Oct 31, 2014 at 18:06

Friday, Oct 31, 2014 at 18:06
Oooh, it was still under warrenty 1 month ago. The merc battery seems fine though. 2011 model
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Follow Up By: jat g - Saturday, Nov 01, 2014 at 07:23

Saturday, Nov 01, 2014 at 07:23
Researching: - The newer model cars EURO 5, 6 and 7 have all varying technology which can make the standard Aux bat relays usless.
Redarc make 3 different BCDC chargers (new name) for each different ECU chips.

Fixed voltage - Temperature compensating - ECU controlled variable.
The quest is to find out which one your vehicle has before buying.

http://www.redarc.com.au/handy-hints/-/new_vehicles_technology_can_affect_dual_battery_systems_charging_performanc/

In the UK business are changing these chips to get better performance and economy over riding the EU standards - is what I am understanding.

Hay Tim,
Do you think your son could tell me what would suit my late 2011 Sprinter.
Anyone with my info on the subject would be helpful.
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Follow Up By: olcoolone - Saturday, Nov 01, 2014 at 08:50

Saturday, Nov 01, 2014 at 08:50
Changing the ECU chip will not alter the charge rates, I think you are getting confused, Redarc make 20,25 and 40amp DC-DC chargers to suit different battery capacities and not the vehicle.

Anyone of these DC-DC charges will work with any system...... but saying that they do make a low voltage DC-DC charger to suit modern vehicles with low charge rates...... the ING and the LV version are the same as each other, they need an 12/24v ignition switch + signal to work.

The non ING and LV models don't need an ignition switch to work, the auto detect when the vehicle starts charging.

You can not use a standard DC-DC charger in a low voltage charge system but you can us a ING or LV in any system (just more wiring).
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Follow Up By: HKB Electronics - Saturday, Nov 01, 2014 at 11:11

Saturday, Nov 01, 2014 at 11:11
Jat g,

You maybe referring to swapping out the alternator regulator with a conventional one, or reprogramming the engine management system to deactivate the smart charge system, this is only applicable to cars with a smart charge systems controlled by the engine management ECU and some of the manufactures are now providing the ability to turn off the smart charge system if required.

Most newer vehicles are still fitted with conventional or high compensation type alternators. With a conventional alternator in most cases you won't have a problem. With the high compensation types a booster diode can be fitted to many models which provides a very cost effective solution.

If you need to managed the charge current ie limit it, then a DCDC can be used for that purpose but keep in mind recharge times will lengthen, if your not going to be doing drive times long enough to recharge the batteries then it may be worth changing the batteries for ones that can accept higher recharge currents.

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Follow Up By: jat g - Saturday, Nov 01, 2014 at 12:07

Saturday, Nov 01, 2014 at 12:07
Got the CTEK 250s DC DC in mind. It is an easy setup. It will boost alternator if I in fact have a smart alternator. I wonder if it will still do the trick even if I just have a normal type. Anything above 2010 quite possible that it will. Anyone know for sure?
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Reply By: Gronk - Saturday, Nov 01, 2014 at 10:27

Saturday, Nov 01, 2014 at 10:27
I wouldn't go down the DC/DC charger path just yet.

1st, I'd find out what the problem is.......and by the amount of replies, there are a few to investigate.

When you find the problem, a DC/DC MAY be the solution, but until you know, it may be a waste of money.
AnswerID: 541169

Follow Up By: jat g - Saturday, Nov 01, 2014 at 12:10

Saturday, Nov 01, 2014 at 12:10
Your right of course. But boy once you start to research it, everone saying the VSR not for modern cars now.
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Follow Up By: Gronk - Saturday, Nov 01, 2014 at 12:27

Saturday, Nov 01, 2014 at 12:27
Well, I have a 200 series with a known low voltage problem and after putting in a booster diode, I have had no problems keeping my 3 x 120 a/h batts in the van charged...all with a $65 GSL batt isolator.

1st, find out the charge voltage before anything else and go from there ..
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Reply By: Winner W - Tuesday, Nov 04, 2014 at 13:17

Tuesday, Nov 04, 2014 at 13:17
Possibly related to the original post. I have one of these 12v solar trickle panels that you plug into the sigarette lighter socket to maintain a battery . I had one on my boat battery but the battery still died after a few months . Testing the output this morning of this solar charger panel it came up as almost 24 volts in stead of 12 or 13 volts . This is surely a fault in the thing as that will destroy any 12 v battery?
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Follow Up By: oldtrack123 - Tuesday, Nov 04, 2014 at 17:13

Tuesday, Nov 04, 2014 at 17:13
H
I suspect you did that test without the battery or a load connected??
Under those conditions 21<22V is normal for 12v battery charging panels
.What capacity[Watts ] is the panel?
What Amhr battery are you charging ?


PeterQ
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Follow Up By: jat g - Tuesday, Nov 04, 2014 at 19:58

Tuesday, Nov 04, 2014 at 19:58
Did you do this test?
TEST - direct to SP leads with nothing connected and in sunlight.
Multi meter settings:
Red lead pluged to 10A
Black in COM.

12V panel.
Short circut current (Isc)
This test should show close to 11.5A

Volts it should be 12V if that is your battery system. If you mean charging Amps 22 is not realistic unless the panel is rated 400 Watt, I am thinking its meant for 24V system at the moment. Need more info as Peter says. Are there Isc and Voc readings on the label?

You can put 24V panels though some of the better solar regulators but your charging power will be halfed.

Battery will go bad if undercharged just the same as overcharged or deep cycled too low too often. Or if batteries are crap.











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Reply By: jat g - Saturday, Nov 08, 2014 at 07:27

Saturday, Nov 08, 2014 at 07:27
Holly help needed!

Fully charged battery reading 13.7V I head off for the day. After running 25Amps of power, cut off switch was activated at 11.5V Max Tempurature - 24
The day before Voltage reached 12.2V - after useing 16Amps although 10Amps came back from solar panels.

To recall I bought new 2 x 100Ah "Full river" batteries 9 days ago.

I now go for anything up to 6 hours per day without mains power. 12V Fridge draws 6.9Amps max per hour and is the main drawer in those few hours. Solar panels 400Watt charge upto 20Ah if daylight and parked in the sun.

Every night l have mains power and nothing runs on 12V whilst battery charger brings batteries into float mode. 13.7V to recall I bought a new IC2500 projecta intelli charger with Tempurature sensor.

SOLAR REGULATOR Dingo 40/40 is set up to monitor everything.
Beginning each day at 12midnight.
Tempurature sensor and reading.
Max Volt
Min Volt
Measures all Power being used and put back (Amps)
Solar panels charge - in
Load drawn Out. External and Fridge via regulator.
History - upto 30 days.

I have an extra cut out relay 11.8V for external equiptment.
The fridge is connected to the load of dingo 40/40 directly, cut off is set for 11.5V

I have disconected Navra from car battery. So am not charging from car battery only from solar panels whilst driving.

Max Volatage since installing - 14.8 V most days I see 14.2 V max reading.

Now who would still believe that it's the batteries after exchanging them 3 times within 1 year.



AnswerID: 541414

Follow Up By: AlbyNSW - Saturday, Nov 08, 2014 at 07:52

Saturday, Nov 08, 2014 at 07:52
It is very hard to get a proper diagnosis over the Internet sight unseen
You obviously have a problem with your setup and are spending a lot of $$$ chasing it yourself using Internet guesses
Maybe you need to seek advice from a professional and get it sorted
1
FollowupID: 827519

Follow Up By: oldtrack123 - Saturday, Nov 08, 2014 at 12:53

Saturday, Nov 08, 2014 at 12:53
Hi
In view of 3 battery changes , Did you actualy have those BATTERRIES checked for remaining capacity [from full charge]
In other words ,were they realy stuffed??

Perhaps the low voltage cut out is the problem

400W of solar should give you around 23A charge current in full sun.

Over an average day, around 130Ahrs into the battery

If the batterries are stuffed, then you do have a major problem
Either:
high current leakage somewhere
incorrect wiring , including with the regulator, monitor

Simply using more power than you think
Are you running the fridge on deep freeze?

I think it is time you sort an expert to check everything over,
some of those voltage readingsyou are getingdo not make sense.

AND do not rush into a DC to DC charger,you could be just throwing your money away
AS posted a 'Booster diode may be all you need,


PeterQ
0
FollowupID: 827527

Follow Up By: oldtrack123 - Saturday, Nov 08, 2014 at 13:03

Saturday, Nov 08, 2014 at 13:03
HI
Cannot edit
But what brand /model of fridge ?

If it is a 3way & you are just running it on 12V, that is most likely your problem

Depending on model they draw from 15 to 23A every second they are running

Over 24hrs, that could be 360<552Ahrs, if left connected to the aux batteries

PeterQ
0
FollowupID: 827529

Follow Up By: oldtrack123 - Saturday, Nov 08, 2014 at 13:15

Saturday, Nov 08, 2014 at 13:15
Ooops
Reading back I see the question of the fridge was answered
{Quote}Fridge is a not 3 way. 12V compressor fridge - Draws up to 7 Amps whilst cooling only a few minutes at time, not per hour! Over 12 hours it will draw a "total"of 8 Amps (seen as load on display of solar regulator) not Amp hours"[end quote]

Something is wrong with those readings!!!
The power use over time should be in Ahrs over & nomally would be in excess of 30Ahrs over 24hrs[depending on ambient temp , thermostat setting , Warm loading,;]for Waeco or Engel
Again I suspect wiring problems .

PeterQ
1
FollowupID: 827530

Follow Up By: oldtrack123 - Saturday, Nov 08, 2014 at 13:26

Saturday, Nov 08, 2014 at 13:26
HI
As a follow up to Jat's
"Did you do this test?
TEST - direct to SP leads with nothing connected and in sunlight.
Multi meter settings:
Red lead pluged to 10A
Black in COM.

12V panel.
Short circut current (Isc)
This test should show close to 11.5A ""[end quote']

That test should be done direct to the panel terminals,[can be at the regulator panel input, itself] not the battery side of the regulator & with the panels disconnected from the battery or any other load

The 2nd test is to determine panel voltage open circuit
Change meter to DC volts & 30V or higher scale
Again check the Open circuit VOLTAGE at the Panel terminals [as above]
For a 12V system, it should be around 21<22V

PeterQ
0
FollowupID: 827531

Follow Up By: jat g - Saturday, Nov 08, 2014 at 14:39

Saturday, Nov 08, 2014 at 14:39
Hi Oldtrack,

Yes it diffenatly does get higher as the outside tempurature increases.
But at 5 to 10 deg. over night 12 hours it sits round 8 Amps. 16Amps over 24Hours where the solar panels kick in.

Just have been testing fridge and 2 fans in shade at 25 deg. on load 7.7A the bat went to 12.9V all a ok. Solar panels 6.5A
Whilst Fridge not running bat reading 13.7V now.

Oh and double check with multi meter proved the Voltage is correct on the display of solar regulator.

See what happens in 1 hour.


0
FollowupID: 827535

Follow Up By: jat g - Friday, Nov 14, 2014 at 14:43

Friday, Nov 14, 2014 at 14:43
Thanks to you PeterQ you got the answer.

Following up:- Regulator readings incorrect.

After already taking readings from Dingo regulator direct, multi meter and with charger at the battery terminals. The results were 0.1 Volt difference only, not detrimental. So it would seems the reading were more or less fine.
Think think think- Ha ! then it dorned on me.
Do a test whilst no charge was coming in either from Solar panels or from the charger whilst on load, in other words when the fridge was running.

Fridge load - 4.9 to 5.3A

Regulator displayed voltage after 5 Mins read 11.4V
Multi-meter reading - 12.7V Direct at battery terminals.
Charger displaying - 12.7V

So that was it!

With the help and support from Plasmatronics who guided me though testing the regulator all seemed fine. So all to look at next was the wiring to battery.
At the fuse in and out it was HOT to touch. So hot that I had to disconect both sides and wait till it cooled. The fuse system which was fitted was as the electrician said not ideal as they tend to arch. So he changes it for a metal box style fuse.

Now readings on load are:

12.5V from Solar panel regulator
12.7V from Multi meter at battery terminal.
(12.55V and 12.68V in fact when using auto electrians multi meter.)

No draw load rested.
12.9V Regulator
12.9V Multi meter at battery terminal.

All very interesting.

So now time will tell how good these batteries really are.

1
FollowupID: 827826

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