I've been using those cheapy hardcase Zippy lipo and don't have any problem with them. They ballanced just fine on the charger. Other racers tried them also and can't tell the difference between them and the name brand ones. The cost of the name brand ones are ridicules, and they're made from the same country. Those name brand companies need to lower their prices by a lot to get my business. It's also the same thing with those lipo chargers.