Short Battery Life Tech Alert

Short Service Life Experience with Batteries

It has come to our attention that two dominant powersport vehicles are sometimes experiencing short battery life. These are V-Twin large cubic-inch custom motorcycles and SeaDoo personal watercraft

V-Twin Custom Motorcycles

With the introduction of large cubic-inch engines, i.e., 108-120+, required starting energy is at minimum double that of stock smaller cubic-inch V-twin engines. The old rule of thumb is that it takes 20 minutes of highway riding to recharge the battery for a single start. These larger engines require at least 40 minutes. These custom bikes generally are ridden more in town, short distances and don’t receive the required ride time to get a full recharge on the battery. This sets up the scenario for the battery to be discharged more than it is charged and after a short time, sometimes-just days, the battery no longer starts the bike. Typical run-down battery voltages are less than 12 volts. Full charge battery voltage is 12.84 volts.


Purchase a Deltran Power Tender Plus 12 Volt 5 Amp Waterproof Battery Charger P/N 022-0157-1. A quick disconnect wire harness capable of carrying 6 amps could be installed for easy connect/disconnect. Always disconnect the charger AC power before connecting or disconnecting from the battery. Use the charger at the end of the riding day and it can be left connected and operating until the next ride.

SeaDoo Personal Watercraft

Most models of this brand of watercraft experience an electrical load on the battery during storage, caused by a control module monitoring the lanyard socket. If the lanyard is left installed the electrical drain is 18 ma after 10 minutes of shutting down the engine. If the lanyard is removed, the electrical drain is 7 ma. These electrical loads are continuous and can accumulate to be significant over time. At 18 milli amps, the battery will lose 1 amp/hour of capacity in 55.5 hours or 10 amp/hours (Ah) in 23 days. On a PC 625, 10 Ah is 59% of battery capacity.


For Sea-Doo watercraft always disconnect the lanyard from its socket when not riding the watercraft. Disconnect the negative battery cable from the battery when the watercraft will not be used for 3 weeks or more. A simplified method of disconnect is to install waterproof battery switch. In both cases, check battery voltage periodically for full charge which is 12.84V. Batteries with voltages less than 12.6V need to be recharged per procedure.


Batteries that are deeply discharged and not fully recharged or batteries that are stored with an electrical load applied with a resultant loss in delivered capacity are not covered by warranty.

Send Questions to: [email protected] or call 800-405-2121.

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