Why is mixing batteries of different chemistries, brands or age a potential problem?
Mixing of battery types (different chemistries, brands and/or fresh vs. used) in a device is not recommended and can significantly increase the potential for leakage and reduced device run time. The primary concern is an imbalance in capacities or available energy between the installed batteries. As the weakest battery becomes exhausted, it will be force discharged by the stronger batteries to very low or negative voltage levels which drastically increases the potential for leakage.
