If the battery is not damaged or totally dead, you can attempt to charge it with any
24-Volt DC charger. The charging voltage rises to about 28 Volts when nothing is
connected to the charger. You must first connect (with jumper leads) the positive
charger output to the positive battery terminal. Use a test meter to determine the
polarity of the battery. Also test the charger output to determine the polarity. Be
sure to connect positive to positive and negative to negative. Do this before turning
on the power to the charger. If the battery is a "smart" battery; that is with built-in
electronic control circuit, the ordinary charger may not work. Normally, a battery
will accept a charge until it is nearly completely charged and then the battery
voltage will slowly "buck" the charging voltage. When the battery voltage and the
charging voltage are equal, no more charging current will flow. Amperes, that is
coulombs of current, charge the battery; when the battery is at (approximately) 24
volts and the charger is putting out 24 volts, NO current flows. The battery is then
fully charged.