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Unread 25-03-2002, 09:16
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Al Skierkiewicz Al Skierkiewicz is offline
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This is a hard question to answer. We have batteries that have been around in excess of four years that are still OK for practice. Funny thing about SLA/Gell cell batteries is that after repeated charge/discharge cycles the electrolyte (the gelled acid) starts to evaporate and the battery actually becomes lighter. Compared with a new battery of the same type you can tell by holding one in each hand, the lighter is the more used battery. If you have a battery that does not have the capacity, terminal voltage or weight of a new battery, it's time to recycle it.
Always remember to portect the terminals during storage and transport of even a damaged or old battery. Any metal coming in contact with both terminals has the potential for a catastrophic failure or fire.
Good Luck All
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Unread 28-03-2002, 15:04
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Joe Johnson Joe Johnson is offline
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Test your batteries

We have just gone through a serious set of tests of all batteries in our stock.

There is a very wide range of performance.

Basically, we bought high wattage Ohmite 1 ohm resistors, banked them in parrallel to give us either .2 ohm or .1 ohm resistors. We plugged in our batteries and then checked the voltage every 30 seconds until the battery voltage went below 8.0V.

This allowed us to rate our batteries as red, yellow, or green.

For us, in order for a battery to be green it had to last over 4 minutes with the .1 ohm resistor. We found that for a battery to be green, .2 ohms required 11 or more minutes to drain it to 8.0V. We stopped doing the .2 ohm test after a while because there it didn't seem to give us any more information than the .1 ohm test (good batteries on one test were good batteries on the other test) and because it took longer to do the test.

Surprisingly, there was very little variation amoung green batteries or best green battery was 300 seconds our worst green battery was 270 seconds.

So, either a battery was good or it was not. It was also surprising how poorly age predicted whether a battery would be green or yellow or red. We had some almost new batteries that were red. We had some batteries from 1999 that were as good as any green battery we have.

I urge everyone to test their batteries. You may be surprised at what you find out.

Joe J.

Last edited by Joe Johnson : 28-03-2002 at 15:08.
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Unread 28-03-2002, 22:24
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Al Skierkiewicz Al Skierkiewicz is offline
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Joe et al,
We have not had a chance to check our batteries this week while getting ready for MMR but this just in, Hammond Beaty reported to me today that there is a 1/2 pound difference in weight in some of the 2002 batteries. Are your bad batteries also lighter? The reason I ask is to weed out whether there was a bad production run. More later...
Good Luck
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Good Luck All. Learn something new, everyday!
Al
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www.wildstang.org
________________________
Storming the Tower since 1996.
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