Battery Chargers

Thank's Mick,
I'll check Jaycar out.
Cheers Dave...

Have been using that very same charger for just on six months now to charge/maintain a 100AH Deep Cycle Battery and have been more than satisfied.

I paid $136:00 and some cents. Don't be afraid to ask for trade discount at Jaycar, even if you happen to be a neuro surgeon. You will be amazed at the number of times you get the discount.

This same charger has quite a following amongst those on the caravan forum.

Ian

Mike,
Yes they are 100Ah battery's,Thanks for info.I thought 30A might be a bit of over kill as I only won't to top up battery's occasionally over night when I'm at home.
Cheers Dave...

"top up" being the operative words here...
Just to top-up you only need a few Amps

However, with-out nominating 'brands' have a look at something that is 3 (or 4) stage and about 15 to 20a MAX, as there is no need to put more than ~10% capacity back into the battery on a continuous charge.

This combination will fully recharge a "flat" battery - as well as being suitable to be left attached continuously to the battery and keep it 'topped up' also - as they are two different settings- saves buying two battery chargers!

Derek
A maintenance charger was what I was thinking of.Would a 15A be capable of charging two battery's linked together over night.
Cheers Dave...

Hi Dave

15A is more than enough. For maintenance a 7 amp would do the job but if the batteries are low and you wish to bring them up overnight then yes 15A is better. The Smart Charger will go into float mode once the batteries are fully charged. You will see this by the float LED and also if you check with a voltmeter the charger should be maintaining a voltage of around 13.8v.

Regards

Derek.

Kiwi Kia,
I have an average charger but if I hook it up to charge over night it will probably cook the batteries.
Cheers Dave...

Are you sure ? It will only cook the batteries if it is not a trickle charger AND your batteries are already fully charged.

Why do you want to leave it on all night ? Check your state of charge and if required only leave the charger on for a couple of hours.

As I said above it's the maintenance charge that needs a little science the rest is rather basic. Some people even use a timer and only leave the charger on for an hour or so every week to keep batteries topped up.

Switching on the charger and going off to the bar and then to bed is not looking after your batteries. Learn how to use a hydometer or a volt meter to check your batteries and then charge as required.

I agree with Kiwi Kia - a cheap basic charger, a time switch (or a watch and a good memory) and a little common sense will do all a smart charger will at a fraction of the price.

It won't do equalisation (before someone mentions it) but it's rare, if at all, that needs doing anyway.

Mike Harding

It also will not check for sulphation like a "smart" charger will.

Smart chargers are for smart people who just want to connect and forget, without causing undue damage to the battery.

If people can justify the higher purchase price of a 3 or 4 stage charger, why criticise there choice guys?

Can the above theory work on all types of batterys including calcium and does it matter what state of charge the battery is in?

Will a cheap normal charge do the same as one of these expensive ones like a Ctek.

Regards Richard

You can write a book on how to charge a battery.
You can write ten books covering everyone's pet theory on how to charge a battery.
Nearly all the charging science and expense is to do with either keeping an unused battery at almost 100% charge OR trying to rescue a battery that is probably on it's last legs anyway.

MY happy little theory is to do it just like your motor vehicle does -with a single stage alternator or generator.

I do not claim to be a battery expert but I have had heaps to do with large battery installations of all types for a long long time. Seen mega-bucks spent on the latest types and chargers. Spent oodles of time writing & compiling data readings on charts and in the long-term the simple (and usually cheap) fit and forget systems came out about equal with the most expensive. Watch the voltages and when they are not keeping up the charge exchange the battery.
Emergency starter batteries
Emergency computer system back-ups
Emergency lighting systems
Nightly use and then daily charge
etc etc.
Some Government departments throw mega-bucks at consultants and their battery backups (airports, emergency services, hospitals, defence, marine etc.) But they can all pack up at midnight during a thunderstorm on Christmas eve. :-))
I am not knocking any system, just suggesting that the expensive ones don't really last much longer then the most basic system.

You check your fuel gauge regularly so how about check the voltage of your batteries ? The only time I would pay heaps extra is when the system is unattended like a lighthouse beacon etc. Most of the extra money is probably only for a very high quality control exercise anyway.

>It also will not check for sulphation like a "smart" charger will.

I am unconvinced electronic analysis will reliably indicate sulfation and even if it did... what's it going to do about it?

>If people can justify the higher purchase price of a 3 or 4 stage
>charger, why criticise there choice guys?

It's not about criticising people but about providing information and helping people to understand there are, often, many ways to achieve their desired outcome. This forum has a regrettable tendency to frequently suggest anything less than the latest wizz-bang expensive product is rubbish and only the top-of-the-range product will do - this forum is frequently wrong in that assertion.

Mike Harding

To Olcoolone,

Calcium batteries need 16V to bring them up to full charge. In the last few weeks I have spoken to 2 battery shop people and both have said this. Something like the Jaycar 4 stage charger can do this. My 3 stage charger cannot.

Cheers,

Mark.

Hi Mark, Are you sugesting that a calcium battery can mever be brought up to full charge in a vehicle ?
16 volts is rather high don't you think ?

Mark H...I have to agree with you on that.
Try charging a flat calcium battery up with a cheap battery charger and see what state of charge it has at the end.

New VE commodores charge at upto 17.6 volts, a car will not charge a flat calcium battery to anymore then about 50%.

If you flatern your calcium battery they recondmend charging it with the correct type of charger before using it again.

Regards Richard

>New VE commodores charge at upto 17.6 volts

Errrrr.... have to say I cannot remember with certainty but I did a fair bit of design work on certain aspects of the VE Commodore electronics and software and I believe the high level voltage cutout was around 16V5.

Mike Harding

My reference is a little dated but it does refer to Calcium batteries;

In a more recent document (8), Bosch recognizes the effect of calcium on battery chemistry. Elsewhere in this same 1995 handbook they recommend that when external chargers are used, lead/calcium and hybrid batteries be charged at no more than 14.4 volts and the charger have a certain characteristic known as "Type IU". The "IU" characteristic is well-defined in this reference. However, under the more controlled environment of an automotive charging system (the regulator is temperature-compensated), voltages greater than fifteen are sometimes useful. At a modest air-intake temperature of 25º C (77º F), this chart suggests settings between 14.3 and 14.7 volts.

It's my understanding that the Calcium battery was introduced to allow a charging process to occur that did not lose water hence we now have sealed batteries. The calcium batteries also have a longer shelf life. I think that they can be charged with a voltage up to 16V without losing water, that does not mean they should be charged at 16V.
Does anyone know the facts from a reputable manufacturer ?

Hi Kiwi Kia,

I'm just going by these 2 guys, one of them said he supplies a couple of big name off-road campers and has numerous arguments with people about calcium battery performance and their non-acceptance of incorrect battery chargers. I'm no expert by any means but I have been calling around as I was after a replacement battery for my camper trailer.

If you check the specs for the Projecta 4 Stage Smart Charger here you will note something in there about Calcium charging "up to 16.0V".

To me, that backed up what 2 industry people told me.

Cheers,

Mark.

In regards to these 2 blokes:
One is the state distributor of the batteries Derek Bester on this site uses and the other an owner of a 'Battery World' place, ex-mechanic.

Cheers,

Mark.

An engine bay of a vehicle is one of the most unstable enviroments around, the main reason for going to a calcium batterys is size versus capacity versus maintainance.

Vehicles are becomming more and more power hungry and demanding on their chargining systems and batterys.

They cannot increase alternator outputs much more due to physical size and noise (electrical noise and dirty signal from the alternator).

The only way is to increase voltage and a standard SLA battery cannot cope with the higher voltage hence going to calcium

Now that voltage and current outputs are controlled by the engine ecu and not the old basic regulator on the alternator charging systems are getting more and more smarter and can control charge and load rate very precise along with maintaining optium battery state.

The biggest advantage with ecu controlled alternators is instead of having only one basic sensor (battery sensing ) controlling it now they are able to have multi input sensors controlling it.

Alot of vehicle components are going to Pulse-width modulation (PWM) conrol now, and the most common are fans, stepper motors, wipers and even lights including high and low beam...so gone are the days off using your test l ght or multimeter to test for power

The VE commodore had a few problems with exploding batterys.

This has been and is a whole new learning curve for the automotive mechanical trades including auto elecs....it means most things learnt over the years cannot be applied to the new age battery, charging systems and controls.

Regards Richard

Hi,
I suggest reading "Energy Unlimited" by Reinout Vader,I was lucky enough to score a copy from Victron Energy.(I have no connection with them in any way) and it really is a mine of information for those of us relying on Battery power,also one of the advertisers on Exploroz Derek from ABR.(No connection etc)
knows heaps. Cheers Snake

MarkH - Thanks for that I will do some more checking.

Olcoolone - interesting...shock horror you are not sugesting that modified sine wave (pwm) is actually used in vehicles :-)) are you. We might be starting another big discussion !
Calcium batteries are lighter for the same output as some of the other lead acid combo batteries. One of the main advantages is that they are able to take a higher chargeing voltage without losing water so they can be sealed. Don't think that you will find the voltages have increased all that much.

Raoul, thanks I will check it out.

Modified sine wave is not used in any vehicles that I know of but pulse width modulation is....these are two very differant things in general terms but I supose PWM is still a modified wave.

PWM has been used in main stream automotive since about 1997 much the same as 3 phase alternators having been used for th last 50 years but alot of people don't look at them this way.

For many years there has be an issue with automotive charging and battery systems regarding how much load they can take, automotive systems are becoming more and more power hungry with things ilke heated seats, front and rear windows..electric steering and seats and soon electric brakes.

Some vehicles even have load sharing now for high demand times.

Alot of alternators on new cars cut out below 1000rpm allowing lower engine idle speeds of around 400 to 500 rpm...why..to lower NVH levels and emmisions.

42 volt systems was going to be the way of the future and BMW would of had a car in the market in 2009 but all that has been scraped,maybe we will all be driving 24 volt vehicles soon.

Battery technology has come along way in the last 3 to 7 years and this is just the start of it.

Regards Richard

Richard, PWM is used for fuel management etc. but I can not see it having any use for battery charging.

Not too mention in driving a stepper motor!

Because PWM needs a stable noise free enviroment alot more then the old way of controlling things.

Don't know any vehicle using PWM for battery charging but it will come...Google PWM battery charging or have a look here-

http://www.morningstarcorp.com/support/Why-PWM/why-pwm-1.shtml

Don't know why they have gone to PWM for stepper motor control...supose it is easier to set up and control other stuff with.

Same as why did they go to canbus sytems and node in automotive when the other system worked fine....because they can!

PWM (Pulse Width Modulation) is a technique whereby a DC current is turned on and off at a predetermined rate, the usual reason for employing such a system is to provide the ability to control the average power dissipated is a DC load without incurring the power losses and heat issues which would result from a series regulation technique. However a major downside of PWM control is the significant issue (especially on high current loads) of RF energy being produced during the switching phase.

A stepper motor:
Stepper motor
is a machine which responds to discrete pulses to control it's motion, these pulses are of a logical nature and are either "step" or "don't step" so the concept of applying a pulse width modulation to the driving pulses of a stepper motor is nonsensical.


The CAN bus is a protocol used to allow components in an automotive system to communicate using a common set of instruction and data (that's the theory anyway! :) it's a bit slow but there were/are good technical reasons for it's introduction – but don’t expect to repair such modules in the field!

The link you provide to a commercial site which talks about using a PWM technique to charge batteries is simply a commercial beat-up and I suspect they would have significant problems obtaining EMC compliance for such a product. Additionally I wonder what the issues of electrical/thermal shock to the battery plates would have in the long term? Finally if you know of any battery manufacturer who recommends using a PWM current to charge their batteries I would be interested to hear of them as I'm currently doing some consultancy work in the field of AGM batteries.

Mike Harding

Mike, PWM is ideal for operating a fuel injection system. Control of the frequency of operation and the length of the opening time of injectors gives very fine control of mixture and injection timing when coupled with exhaust O2 sensors.

Hi Kiwi

Well... by the nature of a four stroke engine I would have though it was essential for fuel injection - but it's not really PWM in the sense that we refer to it in electronics design. ie. the injection solenoid is switched on when you want fuel and off when you don't so by definition that is PWM but only by default.

Pulse width modulation is usually used to control average power and it's frequency and mark/space ratio is independent of the essential requirements of the system whereas, in the case of fuel injection, the switching frequency and time is a direct consequence of the mechanical requirements of the engine.

Mike Harding

Mike don't know any battery manufactures using it but I belive alot of battery powered tools use this method to charge batterys quicker.

Alot of automotive fan motors are using PWM as away of controlling fan speeds...take for exemple BA-BF Falcons have 16 fan speeds for the inside fan and they use PWM.

Geez you guys can prattle on when you get wound up.

I have a Calcium battery in my Commodore (VR Statesman) Its' been there for a bit over 5 years.
Does the Statesman use square wave, sine wave, modified sine wave, PWM, PAM, resonant wave guides,tuned length dipoles, infinite improbability drive? Who gives a rats @rse. It works. It starts the car.
"Move along then, nothing to see here"

As Sand Man said, "Smart chargers are for smart people who just want to connect and forget, without causing undue damage to the battery."

Get over it ;-)

Fair point mate!

The last thing you want people doing on a discussion forum is discussing things!

Mike Harding