... current to all the slots, except the 9V and 12V will be cut off. Once the problem has been corrected ... the alarm will stop and the unit will resume charging.· Ensure you load the batteries in ... charged.· AAA, AA, C, D, 9V and 12VNOTE: The 12V slot is ONLY for rechargeable batteries.Use the tables below ... 606.5 Universal Battery Charger for 1.2V , 9V .12V rechargeable battery