I have a few 12V lead acid batteries in good condition which I would like to use to power a surveillance camcoder on a remote site. Ultimately that will be solar-powered, but in the meantime I would regularly take battery out for recharge and put a freshly charged one instead.
The hitch is that only up to 25% of the battery capacity should be used before it is taken out for top up, because otherwise it will be dead after several cycles.
My assumption is that if the camcoder power consumption is X and the battery can hold Yh amount of power, then the maximum time the battery should be used before recharging is 0.25Y/X hours. Is this roughly correct?
Now, the main question is how to find what Y is. The only other electrical metric labelled on the battery (apart from 12V) is 730 CCA (cold cranking amps). The battery product code is N70ZZMF if this helps.