Batteries during storage

All batteries self-discharge even if they are not operating lights,furnace, radios, etc. 12 volt-powered alarms and electronic control circuits of the fridge, microwave, etc. continue to draw small amounts of power adding to self-discharge action. The design and newness/condition of a battery affects how long a battery will hold a charge. If batteries are kept fully charged and not allowed to remain discharged, they will last longer, hold a charge longer and perform better. Generally, good quality batteries that have been maintained reasonably well may last some ten years. Modern converter/chargers that will keep batteries fully charged, without overcharging them, and depleting electrolyte levels, should keep house batteries in good condition. All chargers will eventually deplete electrolyte levels so RV owners must check levels periodically and add distilled water when needed to keep the plates covered. Many/most RV's do not have provisions for keeping the starting battery fully charged when parked and connected to shore power. Accordingly a Battery Minder needs to be used or a Trik-L-Start device needs to be installed and connected to the starting battery to keep it up when vehicle is not being driven for extended periods and RV is connected to shore power.