Some robot STEM kits come with batteries included. Some can be recharged while installed in the robot kit via some sort of USB cable.
Many robot STEM kits do NOT include batteries. Most rechargeable batteries cannot be recharged while installed in the robot. When they need recharging they need to be removed and put into a recharging station which must be purchased separately.
Most of the batteries are lithium ion types and care should be used in the storage. Apparently to maximize the life of these type of batteries it is best to store them only half charged. When you want to use them, then charge them up to full charge.
If you are going to use a robot kit a lot, you may want to purchase at least 2 sets of batteries and one charger, so one set is being charged while you are using the other set.
The same type of batteries can be used in several different kits.
The Battery Store’s website provides excellant information about the best 18650 batteries, the types and science behind them and how to properly maintain them. The 18650 batteries are used a number of different kits.
The following is a table of batteries and chargers for kits that we have recently purchased. We are NOT recommending either the battery manufacturer or the retail outlet, but providing a know source where the battery and/or charger can be purchased.