Battery Question

[markusmaximus]

Like many of you, I use a battery tender. My 05 still has the original. Here's the scoop from http://www.totalmotorcycle.com/maintenance/battery.htm on determining battery health. This site has a nice chart on % of health based on resting volts.


"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."