For those willing to put some elbow grease into it, there is an almost unlimited supply of 18650 lithium ion batteries around for cheap (or free) just waiting to be put into a battery pack of some ...

Typically, the individual cells in a battery have somewhat different capacities and may be at different levels of state of charge (SOC). Without balancing, the cell of smallest capacity is a “weak ...

There are still a lot of hand-held tools in use with Ni-Cd or Ni-MH batteries. The simple charger has no switch-off criteria, and you need to measure and adjust the charge time, else you will badly ...