Use a multimeter to check the voltage of each cell in the battery. This will help you determine if any cells are significantly weaker than others. You cannot use your regular charger for charging AGM battery and overcharging its results to its sudden death. This method is most effective on lightly vulcanized batteries. Yes, there are other methods you can apply for reconditioning batteries. The way you can use will also depend on the type and size of battery you have. If your reconditioned battery failed the first load test, you need to discharge it and recharge it back. You can do this using a battery load tester which you can buy in any hardware shops. How To Revive Old Lead Acid Batteries In order to&nbsp