Load testing leisure batteries

[Avocet]

I have a single leisure battery that I suspect is a bit "tired". Before I do anything daft, is it OK to put a load tester on a leisure battry? I know it's common to do so on car batteries but I believe that leisure batteries can't supply heavy currents without damaging themselves. Is it the case that a load tester won't really draw so much current as to damage a battery? It's 75AH.

 

[lw395]

Some load testers take as much current as a starter motor.
It's generally a good idea to make a test emulate the use, so a more realistic test might be a few car headlight bulbs in parallel, how many hours to get down to 11.5 volts or so. I have one of those 12v fan heaters that takes about 15A, It's quite useful for judging the capacity of a battery under a 'medium' load.
HTH.

 

[VicS]

It may depend on the leisure battery. My old one (Lucas) was marked with a CCA figure. The new one (Halfords own) is not.

Things you could try though Charge it fully then give it an "equalising charge" which may remove any sulphation.

Or try dosing with EDTA

Or try a pulsator

Links you might like to read

http://www.batteryfaq.org/

http://batteryuniversity.com

http://www.mpoweruk.com

http://www.courtiestown.co.uk/ (for edta and pulsation)

 

[VicMallows]

VicS,

I can't make out whether you're tounge-in cheek on this one or not!

As I always respect your opinions on chemical issues, do you in fact believe in the EDTA theories?

I most certainly agree that a long, current-controlled charge from an adequate voltage source will resurect an awful lot of batteries.

Vic (M)

 

[VicS]

[ QUOTE ]
As I always respect your opinions on chemical issues, do you in fact believe in the EDTA theories?

[/ QUOTE ] The answer is I do not know. It is possible to produce an explanation of how it might work. Basically edta will dissolve lead sulphate, but whether it does so in not so dilute sulphuric acid I would not care to say. As far as I can see it could remove light sulphation and bring a failing battery back into a serviceable condition but I do not think it will restore it to its original capacity. Once dosed the edta remains in the cells and remains active for the remaining life of the battery.

I had a long discussion with "Leadersail" about it some months ago. He claims to have phenomenally good results although even he is not claiming that it will revive a completely knackered battery. Even our naff new search system should be able to find it.

It would be very interesting if a number of forumites could try it on batteries that are not too far gone and report back. I am thinking of getting a few old batteries from the boatyard when people fit new ones this spring and giving it a try. I'll have to be sure I don't use totally useless ones of course and at £3 a throw I am not going to try many. I wish I'd thought of trying it when I had a big jar of unwanted EDTA tetrasodium salt on the lab shelf!

I think the "Pulser" idea is fairly well established although even that may not be proven beyond all doubts.

 

[Anonymous]

[ QUOTE ]
I think the "Pulser" idea is fairly well established although even that may not be proven beyond all doubts.

[/ QUOTE ]I think that pulsers are proven and effective when used in appropriate cases. There must still be enough re-usable lead on the plates, the plates must be reasonably sound, not shorting and the material must not be flaking off in large chunks on every knock or re-charge. There must be sufficient acid left and most likely this will need to be refreshed if EDTA is used.

If you start to use pulsers when the batteries are new, or still in spec, I think you will preserve them.

I have 'repaired' two batteries with a pulser out of two tried. One, a small 15Ah sealed lead acid for a handheld searchlight. The other, an ordinary automotive battery circa 75Ah that was installed with my generator in 1999 and has been allowed to go completely flat several times in my ownership leading to the point that I was going to have to change it. I have paralleled it across my main batteries with a pulser and now it is working 'fine' - I have yet to do a capacity check but the point is that we have gone from a useless piece of junk, new battery required, to a perfectly good battery for this season at a saving of €70 or so, what I paid for the pulser!

 

[VicMallows]

Re: EDTA

I look forward to any feedback you obtain. The 'stuff' has certainly been around and promoted for batteries for a long, long time.

You have probably hit the battery with "at £3 a throw" ... I too would probably experiment if I had quantities of EDTA available 'free'. In the meantime, will concentrate on getting about 6-8 years out of cheap caravan shop leisure batteries.

Am I mistaken, but wasn't it the preservative my contact lenses used to come in?

Plenty of info on the net, but this link amused me...

http://edta.orchidsuites.net/sites/conf2008/

Vic

 

[Avocet]

Re: EDTA

Thanks all! useful stuff, as ever!