Charging Batteries

WARNING: Battery posts, terminals, and related accessories contain lead and lead compounds, chemicals known to the state of California to cause cancer and reproductive harm. Wash hands after handling.

CAUTION: Charging a frozen battery can cause it to explode. Thaw battery at room temperature. Warm battery to 16 °C (60 °F) before charging.

Batteries produce an explosive gas while being charged. Keep sparks and flames away from batteries. Charge batteries in a well ventilated area.

IMPORTANT: Damage to electrical system in machine can result from charging batteries while connected. Disconnect both negative and positive cables from battery terminals before charging batteries in machine.

Stop or cut back charging rate if battery case feels hot, or is venting electrolyte. Battery temperature must not exceed 52 °C (125 °F).

Keep batteries fully charged, especially during cold weather.

Ventilate the area where batteries are being charged.

Determine which battery must be charged.

Disconnect negative battery cable from battery, then disconnect positive battery cable.

IMPORTANT: DO NOT connect or disconnect live circuits. Turn off charger and connect ground cable last, away from battery.

NOTE: Attach a ground strap to negative (—) battery post so ground connection can be made away from the battery.

Connect charger positive cable to positive (+) battery terminal. Connect charger negative cable to ground connection.

Follow instructions provided with charger or refer to the following chart. Always charge batteries with a 12-Volt charger.

Battery Charging Time According to State of Charge and Charger Output
Typical Battery Group Size				Group 31
Reserve Capacity				126—180 Minutes
Charger Output (Amperes)		2	10	15	30	40	60
Battery Voltage (Specific Gravity)1	State of Charge (%)	Charging Time In Hours
12.4—12.6V (1.225)	75%	19	6	5	4	4	4
12.2—12.4V (1.190)	50%	35	9	7	5	5	4
12.0—12.2V (1.155)	25%	51	13	9	6	5	5
11.7—12.0V (1.120)	0%	67	16	12	7	6	5
<10 Volts	Initially set charge rate to BOOST to see appreciable charge. Then switch to medium setting for remaining time.