More often than not, motorcycle batteries fail due to neglect. Bikes often sit unused for long periods, especially during the winter in cold climates, and that can kill a battery faster than you can say, “Hey, my bike won’t start!”
That’s why battery chargers like Schumacher’s SP2 Battery Extender were invented. The SP2 charges at a 1-amp rate until the battery reaches its full voltage, then it goes into “float” mode, maintaining that peak level by either delivering no current at all or, when the voltage drops slightly, a tiny trickle charge before reverting to float. So, you can just hook up the charger when parking the bike for long periods and not worry about having a dead battery when you—or Mother Nature—decide it’s time for a ride.
The SP2 isn’t the first or only charger of this type, but it does offer some features most others do not, such as a 20-foot reach from a 110-volt outlet to the battery via a 14-ft. AC cord and a 6-ft. fused charging cable. It also includes ring-type connectors for permanent attachment to battery posts, a water-resistant connection plug on the charging cable, and a set of sturdy, well-insulated alligator clamps that can be clipped to any battery terminals.
Once connected, the SP2 automatically detects voltage (6- or 12-volt battery), and a series of lights clues you about the unit’s status. Red means the SP2 is plugged in but not connected to or yet charging a battery; steady yellow illuminates when the unit is charging; blinking yellow means that charging has been aborted, indicating a problem with the battery; and green is float mode. The SP2 also will desulfate a battery, a process that, if the sulfation has not progressed too far, can take up to 10 hours.
We left the SP2 hooked to one motorcycle that sat unused for nearly eight months, and it kept the battery fresh and ready to spin the engine at full cranking speed. On another bike, the charger also worked as advertised, continuously flashing its yellow light because the battery’s condition had deteriorated beyond rescue.
Aside from the 1-amp SP2 charger, Schumacher also makes the 2-amp SP1 and 3-amp SP3, which, as the result of their greater charging rate, are more suitable for larger powersports batteries. But for long-term battery maintenance on most motorcycles, the SP2 is ideal.
Schumacher Electric Corp.
801 Business Center Dr.
Mount Prospect, IL 60056
• Long-reach cables
• High-quality alligator clamps
• Can rescue sulfated batteries
• Internet prices are all over the map, from $34.95 to $74.95
• Looks more like an interstellar phase detractor than a battery charger