Looks like a cheap way to get some rechargeable, replaceable batteries. Did you have to build custom circuitry to do voltage conversion, or can the camera charge straight from the batteries? Also, are those off the shelf voltage monitors?

Hey, there is no voltage conversion as makita makes a 14.4v battery that is common to the camera industry. I would love to make a voltage regulator to be able to use 18v batteries in the future. Yes, these are off the shelf voltage monitors, the Chinese variety. There is circuitry to prevent reverse bias to each battery and fuses etc...