Quote:
Originally Posted by crx_rogus
And regulated current into x ohms = voltage, hence my thinking of it in terms of voltage.
Thanks for the responses.
Regards,
Roger
|
Seems like you are applying Ohms law... and makes sense... just don't expect Ohm's law to give you accurate predictions of battery Voltage behavior.... not all the effects in a battery are Ohmic in nature.
The voltage of a battery cell is an effect of the electrochemical potential difference from the chemicals inside.
A NiMH battery at 0% SoC... does not show 0V ... the NiMH cell will still show over 1V per cell even with 0mAh of energy stored in it... and if you put even a small load on it... the 1V will collapse to 0V very quickly... but you take the small load off... and the Voltage will rise back up toward 1V per cell.... the 1V to 0V collapse is not caused by resistance... it is caused by other non-ohmic forces.
Just as a NiMH battery pulled into voltage reversal .... the + terminal becomes negative - and negative terminal becomes positive + ... it does have a negative ( - ) voltage ... but does not have negative ( - ) resistance.
Also the Voltage seen on a battery terminals fluctuates away from the electrochemical potential of the battery the faster / higher the current flow... if you charge with 10 amps the voltage goes up... more than it should just from ohmic forces ... if you take the 10 amps of charging off... the voltage begins to fall back down as the chemical energy inside balances out and catches up.... some of the voltage change is from ohmic forces... but not all of it.
