Are open circuit Voltage and short circuit current measurements a useful and effective way to gauge a battery's condition?
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Short circuit current and voltage measurements?
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Re: Open circuit current and voltage testing?
I believe it depends a great deal on the chemistry - LiIon cells are supposed to have a pretty direct relationship between remaining capacity and open circuit voltage.
Alkaline cells to a lesser extent can also give a reasonable indication of capacity by measuring their open circuit voltage.
Measuring the open circuit voltage of NiMH and NiCd cells on the other hand gives you very little information about their remaining capacity.
An open circuit current measurement isn't going to tell you anything since no current actually flows in an open circuit! I'm guessing that you're referring to flash amping? I.e. putting a meter set for measuring current across the terminals of the cell (very briefly) to determine the maximum current that the cell can supply. Some people seem to swear by it, but it's generally not recommended...
I believe it depends a great deal on the chemistry - LiIon cells are supposed to have a pretty direct relationship between remaining capacity and open circuit voltage.
Alkaline cells to a lesser extent can also give a reasonable indication of capacity by measuring their open circuit voltage.
Measuring the open circuit voltage of NiMH and NiCd cells on the other hand gives you very little information about their remaining capacity.
An open circuit current measurement isn't going to tell you anything since no current actually flows in an open circuit! I'm guessing that you're referring to flash amping? I.e. putting a meter set for measuring current across the terminals of the cell (very briefly) to determine the maximum current that the cell can supply. Some people seem to swear by it, but it's generally not recommended...
Re: Open circuit current and voltage testing?
Yes. "Flash Amping". I've learned a new technical term today. Thank you.
I've just flash Amp'd (very briefly) all of my different NiMH's and am surprised at the results between different makes and models. Maybe I'll do a spreadsheet and post it.
Yes. "Flash Amping". I've learned a new technical term today. Thank you.
I've just flash Amp'd (very briefly) all of my different NiMH's and am surprised at the results between different makes and models. Maybe I'll do a spreadsheet and post it.
Re: Open circuit current and voltage testing?
Flash Amp current depends on the state of charge and the internal resistance (this is also somewhat dependent on the state of charge). Genreally, unless you have a very strict measurement protocol and have tabulated values for all of your cells in any condition, this gives you a very little info.
Flash Amp current depends on the state of charge and the internal resistance (this is also somewhat dependent on the state of charge). Genreally, unless you have a very strict measurement protocol and have tabulated values for all of your cells in any condition, this gives you a very little info.
