Battery Testing for Dummies

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kringle777's picture
Last seen: 15 years 1 month ago
Joined: Friday, May 11, 2007 - 15:54
Points: 132
Battery Testing for Dummies

I'll be the first to admit that I don't know much about electronics and batteries. I build and repair computers just fine, but the circuitry stuff is sort of a mystery. I know a bit about series and parallel circuits, transistors, capacitors, resistors, stuff like that. But measuring batteries and knowing what it means is something else--I've never had to do it before.

All this talk about a single bad battery in a series has got me wondering, how can I tell if I have a bad battery?
I don't ride my XM-2000 far enough to really tell if my range is being limited, and I imagine that even if things are fine right now, at some point in the future I'll have a bad battery (or two) and I'll need to do something about it.

So, what do I need to do to test my series of batteries? Measure each (in my case, 12V 38AH) battery with a multimeter? What would I be looking for? Order some PowerCheq's and attach them? Would that help anything? And finally, if I did happen to add a fresh new battery to a set of old ones, would anything be affected?

Any pointers would help. Thanks!

Red XM-2000
Moss Green "Charger" ebike
Sacramento, CA

Gman's picture
Last seen: 16 years 1 month ago
Joined: Monday, November 20, 2006 - 23:24
Points: 1720
Re: Battery Testing for Dummies

` :?
Sounds like a good mandatory class, it seems we only take it when there is a problem and the batteries are already starting to degrade.
I know basic electricity and Aircraft electrical stuff, that's about it.
I like the way usatracy did, he started off taking readings and recording them as soon as he received it. I'd say that's step #1.

Peace Out,

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HCT's picture
Last seen: 9 months 1 week ago
Joined: Wednesday, February 7, 2007 - 08:16
Points: 137
Impedance ::: Battery Testing for Dummies

Been working with batteries for over 40 years , the first thing I do when trying to determine the condition of any rechargeable batteries regardless of chemistries is to measure its impedance , with lead acid pack , each cell is not accessiable and therefore one cell with high impedance will prevent any energy to be drawn out of the remaining cells.
When I encounter a high impedance cell or pack ,will tried to recharge at a slow rate C/20 to a low as C/100 .
Since any attemp to recharge a high impedance cell or batteries will most likely damage it by the heat created when forcing high current into high impedance .
Have been able to bring back cells of different chemistries that where as old as 30 years .
The process is slow , if the impedance lower after each charge discharge cycle , then the cell is recoverable to some extend .
Impedance measurement is the far most important parameter than voltage or even Amp/Hour , since having a 48 volt pack with 200 A/H capacity with a impedance of several hundred ohm will only allow you to take that 200 A/H over a 1,000 hours pretty useless for vehicul application .
It will do fine to power a transistor radio for quite a few months .

Heat is the surest batteries killer , heat generation is in direct proportion to impedance , both charge and discharge , so the lower the impedance , less heat, less damage to batteries , longer life


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