Author Topic: Controlled Discharge  (Read 1348 times)

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HenryVG

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Controlled Discharge
« on: June 11, 2007, 05:10:30 PM »
I've received some used 105 batteries that I'm desulphating in hopes of using as a battery bank. I know I can use a hydrometer to check the level of charge, but I'm reading here that to really check capacity, I need to do a controlled discharge. Is there a way I can do this with a salvaged car headlight or the like? I'm looking for a way to evaluate if these are worth my time.
« Last Edit: June 11, 2007, 05:10:30 PM by (unknown) »

AbyssUnderground

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Re: Controlled Discharge
« Reply #1 on: June 11, 2007, 11:20:43 AM »
Get a car headlight of a known value (say a 55w bulb) and discharge the battery (from full) and time how long it takes to hit 10.5v. You can then work out the time vs amps to see what the amphours are.
« Last Edit: June 11, 2007, 11:20:43 AM by AbyssUnderground »

Nando

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Re: Controlled Discharge
« Reply #2 on: June 11, 2007, 02:07:22 PM »
What I have done in the past, to check batteries life.


I have used a cheap battery operated large ANALOG display clock, driven by the same source I have been testing, with resistor current limiting for 3 diodes ( two silicon diodes and one Schottky diode) to keep the voltage at 1.5 volts


A circuit that turns the load, in my case a constant current load that when a defined voltage of the battery is reached the circuit drops the load and at the same time the clock stops working, giving the total hours run.


Nando

« Last Edit: June 11, 2007, 02:07:22 PM by Nando »

HenryVG

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Re: Controlled Discharge
« Reply #3 on: June 11, 2007, 09:14:13 PM »
Thanks guys, I knew there'd be a way to do this.
« Last Edit: June 11, 2007, 09:14:13 PM by HenryVG »