Technical Support General information for AGM and GEL Lead-Acid batteries:                                                     BATTERIES In most cases, powerchairs and scooters utilize AGM or GEL lead-acid batteries.  They are similar to a car battery except they do not have any free electrolyte (acid) and should not vent gasses into the air under normal conditions.  Thus they are generally safe for use and will not spill if turned upside down or the case is damaged.  In general the below information is correct.  But check with the battery manufacturer and/or powerchair supplier for their recommendations and precautions on battery care as they may change. Fully charge immediately after each use for improved life (overnight). Do not allow batteries to remain uncharged for more than 1 month at a time.  Charge for 24 hours or more each month when not in use. Keep batteries clean and dust free. Batteries should last 1 to 3 years depending on amount of use and care. It is best not to charge the batteries if below freezing or above 90F (battery may vent gasses or explode). For freezing conditions, it is OK to begin charging when the temperature is above freezing and keep on a continuous charge until use even if the temperature drops below freezing.  This will help keep the electrolyte (acid) from freezing.  But do not begin charging when the temperature is below freezing. Battery MaximizerTM chargers may be left connected and charging continuously at normal room temperatures. If the battery runtime seems to be getting low, try charging continuosly for 48 hours.  If it is still low, new batteries may be needed. If you suspect a battery problem or if the runtime is getting too low, do not charge.  Have the batteries inspected. BatteryMaximizerTM  All rights reservied.  BatteryMaximzierTM is a trademark of TruPower LLC