Different types of batteries, have the reasons for the expansion is not the same as, for the reasons for the expansion of rechargeable batteries are: 1. Bad battery protection circuit 2. Battery without protection in batteries expansion 3. Chargers bad performance, too large a charge current Battery expansion 4. Battery by the current high-rate charge for a 5. Battery design their own problems, may also appear that the general situation of the battery cell expansion is mainly due to: a, raw materials impure b, electrolyte precipitation c, storage and Humid