#14 - Renewable Energy > Technical Discussion: Solar Electric System - Photovoltaic > Re: outcome of voltage in series and amp/h
A simple bench experiment would prove this concept. If you series wired a C cell and an AA cell (battery neg to pos), and a flashlight bulb, you would have a 3 volt battery pack using the bulb as a load device. (sub C and AA nicad battery would be a better example of a rechargeable power source and would yield better result). Assuming a fresh charge on the batteries, the bulb would burn brightly at first, and then, after some time, the bulb would dim as the batteries run out of capacity. The first battery to go flat would be the smaller AA battery, and the C battery would not serve to charge it further, but rather, would discharge it further. Eventually, the smaller AA battery would totally run out of capacity and would go resistive, exhibiting a reverse polarity voltage across its terminals. The battery may or may not recover from this discharge state, and may be permanently damaged by the polarity reversal. A lead acid battery most certainly would be permanently damaged. From this test, one can conclude that the capacity of the battery pack is that of the smallest battery, and that the batteries should have been the same capacity rating for best results. All multiple cell battery packs are, or should be, critically balanced for cell capacity to get the best performance from the battery pack. If you have had experience with rechargeable battery packs and banks, as I have, you should know this concept.