Supports Over-charged/discharged, Over-voltage, Over-current and Short circuit protection. When a load is connected to the battery, the battery shuts off, it may be over-current or short circuit protection, You just need to connect the charger to charge it and the battery will return to normal. The size of the output port: 24V output port is DC5521, 12V output port is DC4017. AC/DC 29.4V / 0.95A charger and cable are included. If you have any questions, please contact us for technical support. Will not charge? Please contact seller immediately to replace a new charger.