This waterproof, fully-automatic charger is ideal for both short term and seasonal storage, even if moisture sneaks into your storage area. The three-step charging system constantly monitors battery voltage to bring the battery up to full charge and switches to float mode to maintain the charge over extended periods of time. The vibration- and shock-resistant Battery Tender is reverse polarity protected and sparkproof, even when the leads touch. The Tender features 2 front panel LED lamps that indicate the battery’s state of charge. 3 YEAR Manufacturer’s warranty.