more lead acid questions

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mab
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Joined: Sat May 03, 2008 4:58 pm
Location: Brighton Marina

more lead acid questions

Postby mab » Mon Nov 10, 2008 9:40 pm

Hi Folks,

I've got a few random questions on lead acids (apologies if they've been asked before but my searches didn't show up the answers):

1/ In a prevoius post, JonSpence grouped lead acids into the following categories:

Starting,
Leisure, Semi-traction.
Traction,
Deep cycle,

I understand the difference between starting (high amps low discharge depth) and deep cycle batteries(low amps deep discharge), and I understand that leisure is a half & half battery, but what's the difference between deep cycle and traction?


2/ I recently acquired six old traction batteries (chloride motive power 12v 100Ah). They show a voltage of 11.8 - 12.1volts a day or so after charging and cannot be raised above 13.4 without excessive charge currents.

I measured the capacities of each one (48amp load to <10volts) and got three batteries of less than 3Ah, two that gave ~25 Ah and one that managed 39Ah. Given the high rate of discharge I thought the 'good' one wasn't bad, but the low charged voltage suggests it's rather past it. Are traction batteries normally 'low voltage'?

Is it worth trying any restoration tecniques on these batteries (like replacing electolyte) or am I wasting my time?


3/ I'm looking for some new batteries for a new solar / wind power supplied home power system (assuming the above traction batteries are beyond help). There are some ex-UPS 12v 100Ah yuasa batteries on ebay for £45 at the mo'; two different types from the same supplier:- endurance enL100-FT ( 220309448254 ) / NPL100-12 gel cells ( 220309452086 ). What's the difference between these (I couldn't get any info off two different Yuasa webites.

Are these a good choice or can anyone recommend cheaper / better.


cheers

Mab

mab
Posts: 34
Joined: Sat May 03, 2008 4:58 pm
Location: Brighton Marina

yuasa website

Postby mab » Mon Nov 10, 2008 9:47 pm

I take back what I said about yuasa websites - I found some technical desctiption and the endurance batteries seem to be higher spec.

mab

JonSpence
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Joined: Thu Jan 03, 2008 1:05 pm
Location: Rochdale

Re: more lead acid questions

Postby JonSpence » Tue Nov 11, 2008 9:52 am

mab wrote:1/ In a prevoius post, JonSpence grouped lead acids into the following categories:

Starting,
Leisure, Semi-traction.
Traction,
Deep cycle,

I understand the difference ..., but what's the difference between deep cycle and traction?


As I provided the terms I suppose that I should explain what I understand them to mean. I agree with your understanding of the first three.

The difference between the last two is a bit academic. Traction batteries will be Deep cycle. The key difference is robustness of construction and a recognition that the battery orientation will change constantly in use. For example as your vehicle climbs a hill. This seldom happens with off grid houses. In practice you are unlikely to find a deep cycle battery that doesn't perform as a traction battery.

mab
Posts: 34
Joined: Sat May 03, 2008 4:58 pm
Location: Brighton Marina

batteries

Postby mab » Tue Nov 11, 2008 7:18 pm

Aha! thanks for that - I suppose then that my old traction batteries may not be so good for static use? They'll suffer from stratification for e.g.?

I suppose then that ex-UPS batteries would be most suited to standing around as that's what they're designed for.

That only leaves the question, are my old traction batteries worth trying to recover for when I start my EV project (still only exists on paper)?

Thanks
mab

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ChrisB
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Postby ChrisB » Thu Nov 13, 2008 11:02 pm

The old chorides are normally pretty robust. Really depends how old they really are.

Without knowing how long you've charged them for and at what rate its tricky to tell, you might find a long slow charge may help.

Does sound like they have got some internal shorting going on though.

ChrisB
I reject reality and substitute my own !!!!!!

xipi frank
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Joined: Fri Nov 14, 2008 4:28 pm

Postby xipi frank » Fri Nov 14, 2008 4:35 pm

Hi Try www.chinadepot.com They sell battery renovator + a battery

Desulfater Hope this helps

Frank

mab
Posts: 34
Joined: Sat May 03, 2008 4:58 pm
Location: Brighton Marina

chlorides

Postby mab » Sun Nov 16, 2008 12:39 am

Does sound like they have got some internal shorting going on though.


I thought that a shorted cell would give me 10ish volts? They were fast chrged to about 13.5v then slow charged (~1 amp) for a good 24hrs. during the last 12 hrs the voltage didn't seem to go up at all (stayed at about 13.4v).

Hi xipi frank, I assume their renovator is EDTA. does anyone have any proof if these electronic pulse desufators actually work? (most of the claims I've seen seem to come from manufacturer's or sellers).

thanks for the replies guys

mab

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ChrisB
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Postby ChrisB » Sun Nov 16, 2008 10:10 pm

Sorry, perhaps shorted was the wrong term to use.

I suspect internal discharge due to small shorts/bridges due to build up of sediment possibly in the bottom of the battery is causing the battery to not be able to reach a decent voltage and also why it drops off so quickly.

All in all its just showing that the battery has reached the end of its useful life really :cry:

EDTA and other such pulse desufators in my view just dont work on a battery that has reached the end of its life, yes they work to a degree on a new battery that has just been left and become sulphated but on a battery thats been worked hard and has done its cycle life or has been abused then they IMO just dont work, like you I've only ever seen fantastic reviews by suppliers etc :roll:
I've used EDTA and it didnt make any difference when tested between two chloride traction batteries that where 15yrs old and had been used for about 1/2 of their life and then left to rot in a field, neither recovered any better than batteries that I just left on a VERY long slow charge.

ChrisB
I reject reality and substitute my own !!!!!!


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