Jerry G. wrote:
On Jul 10, 1:46 pm, John Robertson wrote:
SparkyGuy wrote:
Gell-cell batteries in UPS's: other than loading with a known load and timing
how long it takes to drain the battery, is there a simple way to measure the
health of a gel-cell? Impedance?
Thanks,
S.
How about ESR? Bob Parker's Blue ESR meter will give you some static
clues as to the condition of batteries if compared to known good ones...

http://www.flippers.com/esrkthnt.html(near the bottom of the page)

John :-#)#

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Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
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"Old pinballers never die, they just flip out."

If you put an ESR meter accross batteries you will blow the meter!!!
ESR is to be measured with no active voltage!

Not in this case - the Bob Parker ESR design can handle up to around
45VDC (input cap is rated at 50V) safely, but I have an 18V MOV on mine
to help protect against higher charges.

If you had looked at the link you would see the chart shows a few
batteries with typical ESR values. I posted that years ago (a fellow in
AU created it) hoping to get some interest in folks seeing if ESR would
help show if batteries are failing and be able to monitor them as a result.

A simple circuit that would start beeping when the batteries reach a
certain ESR = time to test!

John :-#)#

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(Please post followups or tech inquiries to the newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."