I noticed something strange with 'charger bots'. I use two bots per section of the map to recharge other bots, so they can charge each other if they run out of battery themselves. I've noticed that when one 'charger bot' runs up to a bot that's out of battery, the other 'charger bot' will stand still, waiting, until the first one has charged the bot that was out of battery. Then the 'charger bot' that was standing still will run up to the bot that was just charged, as well. It looks as if a bot running out of battery flags all 'charger bots' that have it within its working area, and then they take turns trying to charge, while obviously only the first one needs to.