Rechargeable battery charger system for charging testing, rejuvenation and preventative maintenance

A method for automatically rejuvenating and maintaining rechargeable batteries at maximum capacity, said method comprising the steps of:

• detecting the presence of the battery;
• initially discharging the battery to a selected value of deep discharge, said selected value being above the level of cell reversal;
• initially recharging the battery to its rated capacity;
• subsequently discharging the battery at a controlled rate and measuring the battery output voltage, and determining whether the output voltage is above a selected minimum voltage for a selected discharge period;
• if the battery fails to meet the selected minimum voltage for the selected discharge period, continuing to recharge and redischarge the battery until the battery meets the selected minimum voltage for the selected discharge period or for a selected number of cycles to rejuvenate the battery by removing any reversible memory effects;
• if, after the selected number of recharge and redischarge cycles, the battery voltage continues to fall below the selected minimum voltage for the selected discharge period, discarding the battery as having irreversible memory effects;
• if the battery is not discarded, further recharging the battery to its full rated capacity;
• maintaining such full rated capacity by trickle charging;
• and
• periodically repeating such steps of discharging to deep discharge and recharging to full rated capacity to avoid onset of battery memory caused by prolonged charging.