This simple, easy to use piece of equipment can save you quite a bit of money when it comes to batteries. Just wire the included hardware up to your bike, plug it in and you’re all set. A replacement OEM battery can run upwards of $300, depending on the model and a winter of your bike, sitting in the garage can flatten your battery to the point of no return. This device does more than simply charge your battery; it conditions it so that it produces more power over a longer period of time.
A Battery Tender Jr. doesn’t take up much space in the garage nor does it weigh a ton on the bike. You have two options for connecting it to your ride: alligator clips (the less permanent way) and ring terminal adaptors. The alligator clips are good for items you don’t intend to keep around, but we prefer the ring connectors as they’re simple to affix and require less fiddling every time you go to connect it to your bike. You can’t screw up polarity either, as the device has an automatic polarity sensor and switches circuitry accordingly.
If you’re using the ring type connectors, it becomes very easy to secret the charging harness on your bike for both quick access and easy hiding. The plug at the end of the charging unit that installs on your bike also includes a cap to keep debris out. Aside from removing whatever bodywork required to get at your bike’s battery, actually attaching the ring harness to your bike should take no longer than a few minutes.
The device actually charges and maintains a battery in a four stage process: initialization, bulk charge, absorption charge and float charge.
Initialization: This cycle occurs upon initial connection and verifies what the appropriate voltage the battery it’s connected to takes as well as checking proper connection both at the bike’s end and the wall outlet’s end. Think of it as a learning and safety stage.
Bulk Charge: Once the Battery Tender has learned what it’s up against, it applies a constant, full-power electrical current that’s optimized to the exact battery it’s connected to. This bulk charge lasts until the battery is somewhere around 75-80 percent of its full charge capacity. The circuitry is intelligent enough to recognize the subtle differences between two of the same model batteries. In other words, every battery gets a custom charge.
Absorption Charge: This stage conditions the battery for maximal output when it is disconnected from the Battery Tender. Depending on the type of battery, this may last minutes or hours.
Float Charge: Even if your battery sits and is connected to nothing, it still slowly loses power. It is during this stage that the circuitry within the Battery Tender monitors current within the battery with a low amperage input. Be it days or months, when you’re ready to ride again, your battery will be as powerful as ever with this system attached.
Regardless of climate, if you store your bike for more than a few days at a time, a Battery Tender Jr. is a good investment. Repeatedly leaving your bike to sit and then asking its battery to generate a lot of power to turn the starter is a good way to kill it. Be it conventional led-acid, sealed or gel-cell battery, the ‘Jr. model is safe for your application and keeps your battery topped up whenever you’re ready to roll.