Dayton Sons of Israel
A Chavurah of Jewish bikers
Motorcycle Battery Maintenance
Tip: There are dozens of parts on a motorcycle that could be checked on a regular basis and there is nothing wrong with check all those parts. But try to slim the list down to the most important items so you still have time to ride.
The Battery
THE BASICS
First things first. A 12-volt battery is not a 12-volt battery. Twelve volts is just a nominal, convenient term used to distinguish one battery from another. A fully-charged 12-volt battery, allowed to "rest" for a few hours (or days) with no load being drawn from it (or charge going to it), will balance out its charge and measure about 12.6 volts between terminals.
When a battery reads only 12 volts under the above conditions, it's almost fully depleted. Actually, if a battery's resting voltage is only 12.0 to 12.1 it means only 20 to 25% of its useful energy remains. It's either a goner or it has been deep cycled, and a battery can only be deep-cycled a limited number of times before it is indeed dead.
12-volt batteries supply useful energy only through a limited range -- from over 14 volts (when fully charged and unrested) down to 10.5 volts in use/under load (when lights dim, your motorcycle is hard to start). No 12-volt battery will remain at over 14 volts for more than seconds unless it's being charged. The lowest limit is 10.5 volts (used in testing) and obviously unsatisfactory in practical use.
NOTES: Keep in mind that listed voltages are "Resting" Volts.
Maintaining Your Battery
Tip: Check the fluid levels on each chamber. If any chamber is low, carefully top it up. Use only distilled or deionized water, NOT tap water. Tap water has minerals in it that will not do the battery any good.
The humble battery is a very common cause for motorcycle breakdowns! Unfortunately they are awkward to get to and therefore do not get checked as often as they should.