How Long Should Battery Last ( 2nd part )

( The Motorcycle Batteries )

... continue from 1st part

Too High a Battery Charge Level

Yes, there are those who overcharge the battery. The usual belief is that during overcharge, the battery may lose some water which can then be easily replaced. Not so exactly. During overcharging, there is an abundance of oxygen gas released from the decomposition of water in the electrolyte. That passes through the cell areas and oxidizes the positive plates of the battery. This oxidation impairs the conduction of electricity and reduces the capacity of the battery.
Low Electrolyte Solution

This is usually an owner induced problem due to neglect and will subtract from battery longevity. It can also happen from long trips where the battery is continually fully charged and yet continues to charge, decomposing the water into hydrogen and oxygen gasses (called gassing). When the level of electrolyte drops, the upper part of the plates become inactive, further causing a reduction in total battery capacity. It also causes further heating due to an increase in internal resistance of the cells, and resulting heat damage.

I should mention that higher-voltage regulators (as some advertise) are not always a good idea. For short rides and commuting, maybe the higher voltage regulators make sense, but they do not see the higher voltage until the battery reaches a minimum charge level, so the reasoning justifying their use is superfluous to some extent. Batteries will charge just fine with as little as 13.5 volts applied to them, it just takes longer. BMW's standard voltage is 14.0 and it would be best to stick with that (using the standard regulator). Higher voltage regulators can easily cause additional water consumption and increased internal battery heating and result in the problems listed above.

Poisoned Electrolyte

Only distilled water should be used in the makeup of the electrolyte. One heavy dose of a high mineral content water can contaminate a battery and cut its life in half. High mineral content reduces battery electrolyte effectiveness as the minerals are foreign to the needed chemistry. Self discharge rates will increase along with sulphation and internal heating.
Overfilling the Electrolyte with Water

Clearly this is a man-made virus, as the temptation is to practice the theory that more is better. Absolutely not so. Overfilling causes two damaging problems:

During charging, gasses are generated within the electrolyte and will raise the level of the electrolyte , which is normal. But when it is too high by overfilling, the excess will spit out the vent, possibly causing corrosion on the motorcycle, and dilution of the electrolyte, which reduces battery capacity and causes excessive internal heating.

Overfilling can under extreme circumstances, also cause a liquid short circuit between each of the cells and create havoc with the heat so generated. This may destroy the battery and under some circumstances, cause it to explode with the high heat conditions generated.

So when they say don't overfill, they mean it. All that is really necessary is to insure that the top of the separators are covered with electrolyte. The level admittedly, is hard to observe. To ease that problem, shine a light through the battery from rear to front (bike on centerstand).

( The Motorcycle Batteries )