Re: (ET) Battery Testing

["David Roden" <etpost drmm net>]

On 29 Nov 2007 at 15:32, Rob Brockway wrote:

> Does anyone have any tips for testing
> the battery pack so I can estimate the % capacity I have compared to new?

The only way to reliably test capacity is to test capacity!  Apply a known 
load to a fully charged battery and measure the amount of time it 
operates.  
Compare with the battery's amp-hour specifications (be sure you use the 
figure for that load).  A battery which won't produce 80% of its rated 
capacity is usually considered spent.

Since most golf car batteries are rated for minutes at 75 amps (typically 
105 to 125 minutes) that's probably the easiest and most useful 
measurement. 
 

The dummy load can be a commercial tester or can be homemade.  I use 
heating 
element from derelict heat pumps.  A fixed resistance like this isn't a 
constant current load, since the current falls as the voltage falls, but 
it's close enough for most purposes.


David Roden - Akron, Ohio, USA

= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = 
Note: mail sent to the "etpost" address will not reach me.  To send 
me a private message, please use the address shown at the bottom
of this page : http://www.evdl.org/help/
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
     Liberalism is trust of the people tempered by prudence.
     Conservatism is distrust of the people tempered by fear.

                             -- William Gladstone

= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =