Review on Tenergy TN456 Intelligent Universal Battery Charger: 4 Slots, LCD Display, USB Output, Power Adapter - Ideal for Li-ion, NiMH, and NiCD Rechargeable Batteries by Lisa Varela

This charger is very good at eliminating mismatches when charging ALL THE SAME batteries! DO NOT use other brands of batteries and/or mAh batteries in this charger! It assumes they are all the same battery and constantly adjusts the power it puts into each battery based on battery resistance/ohms, voltage and possibly other measurements it takes. You can tell the batteries are getting warm when they are all aligned because they are being charged evenly. After a while, however, they stop syncing and while it shows that it's giving them power in the form of mAh, it's not; or it's not as much as it says because they're starting to cool down. But apparently during this "cooling down" period it reanalyzes their capacitance, resistance and voltage to determine which cells need more or less current to make them all "even". This is VERY IMPORTANT as you want all of your batteries to hold the same power so when used in one device they all die almost at the same time. This prevents deep discharge that could damage the battery.