How do I charge a battery thats been sitting in the basement for a few months, when my TC10 won go out of bulk mode?
TC10 amp charger is recommended for batteries in the 25-200Ahr range. A relatively large battery (or bank), or one that is partially sulfated can exceed the 10 amp charger’s ability to bring the battery to full charge. The charger normally applies 10 amps in bulk mode until the battery’s terminal voltage approaches 14.4 V (until the “flooded” battery charges up). This point normally corresponds to an approximately 70-95% charged state depending on battery capacity and condition. Once 14.4 V is reached the charger goes into absorption in which the battery no longer requires the full 10 amps to maintain the 14.4 V. In other words, the charge current drops below 10 amps until it reaches only 1 amp or 6 hours elapse, then it goes into float mode. If the battery bank is large (e.g. 200-800 Ahr) it will usually reach full charge. However, it will take much longer (perhaps days in an extreme case) for the battery to reach a 90% charged state. At that point the charge current would drop below
