bmwmotorcyclebattery.com

In many models, particularly oil-heads, BMW has not made it very easy to service the battery. Many late model "R" series bikes, for example require all side fairings to be removed (about 20 screws) , and the gas tank to be either disconnected, or moved out the way. Not only is this a burden, but you also risk scratching plastics and wearing threads every time you perform this procedure.

Consider taking the following steps to reduce future service if you own a bike with a difficult to access battery:

1. Purchase an AGM, or other sealed-type battery. Although some people prefer conventional batteries, AGM and other sealed designs are generally more reliable. Moreover, flooded batteries will require you to periodically check the battery to ensure a proper electrolyte level.
2. If you choose a flooded battery, (also some BMW motorcycles do not have a direct-replacement sealed battery), it is best to choose a low maintenance design (such as Yuasa's Yumicron CX), when possible. Be sure to properly initiate the battery by adding the correct level of distilled-water-to-acid, and fully charging it prior to use per the manufacturer's instructions. Also make sure that any vent hoses are properly routed and not kinked.
3. Plan to charge your battery. If you're using a BMW (etc) battery charger that plugs through the accessory outlet, make sure it is made for your battery type, i.e., don't use a gel battery charger on conventional/sealed batteries or vice-versa. Some newer (2004 +) models are equipped with a special charging outlet. Alternatively, you can install an on-board charger, buy a charging adapter for the accessory outlet, or add a charging harness that works with your charger (such as a female cigarette-lighter adapter, or jump-start post). Never charge at a rate greater than 2.5 amps through the accessory outlet. Once again, it is prudent and some people prefer to remove their battery before charging.
4. Prepare your battery. Even if you purchased a sealed battery that claims to be "ready for use", it is still a good idea to make sure the battery is fully charged before installing it. Also, applying di-electric grease, or Vaseline will help prevent corrosion.

Trip Planning and Jump-Starting

If your battery is difficult to access, it is also a good idea to check before going off-road or on a long trip. Using a load-tester is best; if it is a conventional battery, be sure to test the specific gravity with a hydrometer. Also, keep in mind that standard jumper-cables will not work if you cannot access the battery. Attempting to jump-start off a car battery through the accessory outlet is not a good idea and will likely blow a fuse. Most 2004+ models have jump-start posts to make this easier, a similar accessory can also be purchased and fitted to most older models. Before embarking on a long trip, it should be noted that most fuel injected BMW motorcycles cannot be push-started once the battery is severely drained.