TigerhawkT3
Flashlight Enthusiast
How does a cell get charged? What terminals are connected where, and in what way? Series? Parallel? Polarity? How much voltage is too much? 
All I know is to follow chargers' instructions, and they don't explain much beyond how to use the things.
The reason I ask is because I'm making a little backup battery pack for my portable video player, and I'm not sure how to continue. The AC/DC adaptor that it came with is listed as 5V, and the device has (I'm guessing) a single Li-Po cell inside. My question is, What voltage should I use for my battery pack? Should I use 4xNiMH, which will dip slightly below 5V for a significant portion of the battery life, or should I use 6xNiMH, which will always be above 5V to some small degree? The device accepts a 12V car charger, but I don't know if the charger has extra guts in it that step down the voltage from 12V to around 5V, or if the protection is in the internal battery and just steps down whatever voltage it receives, or if having a significantly higher-voltage charging source even matters, or what.
All I know is to follow chargers' instructions, and they don't explain much beyond how to use the things.The reason I ask is because I'm making a little backup battery pack for my portable video player, and I'm not sure how to continue. The AC/DC adaptor that it came with is listed as 5V, and the device has (I'm guessing) a single Li-Po cell inside. My question is, What voltage should I use for my battery pack? Should I use 4xNiMH, which will dip slightly below 5V for a significant portion of the battery life, or should I use 6xNiMH, which will always be above 5V to some small degree? The device accepts a 12V car charger, but I don't know if the charger has extra guts in it that step down the voltage from 12V to around 5V, or if the protection is in the internal battery and just steps down whatever voltage it receives, or if having a significantly higher-voltage charging source even matters, or what.
