Two wheeler batteries may last as little as 2 years, or as much as 10 or 11. A lot depends on how they are stored and cared for.
There are many things that can cause a battery to fail or drastically shorten its life. One of those things is allowing a battery to remain in a partially discharged state. We talked about sulfate forming on the surface of the battery’s plates during discharge, and the sulfate also forms as a result of self-discharge. Sulfate also forms quickly if the electrolyte level is allowed to drop to the point that the plates are exposed. If this sulfate is allowed to remain on the plates, the crystals will grow larger and harden till they become impossible to remove through charging. Therefore, the amount of available surface area for the chemical reaction will be permanently reduced. This condition is known as “sulfation,” and it permanently reduces the battery’s capacity. A 20 amp hour battery may start performing like a 16 amp hour (or smaller) battery, losing voltage rapidly under load and failing to maintain sufficient voltage during cranking to operate the bike’s ignition system. This last condition is evident when the engine refuses to fire until you remove your finger from the start button. When you release the starter, the battery voltage instantly jumps back up to a sufficient level. Since the engine is still turning briefly, the now energized ignition will fire the spark plugs.
Deep discharging is another battery killer. Each time the battery is deeply discharged, some of the active material drops off of the plates and falls to the bottom of the battery case. Naturally, this leaves less of the stuff to conduct the chemical reaction. If enough of this material accumulates in the bottom of the case, it’ll short the plates together and kill the battery.
Overcharging is an insidious killer; its effects often aren’t apparent to the innocent purchaser of the ten-dollar trickle charger who leaves it hooked to the battery for extended periods. A trickle charger charges at a constant rate regardless of the battery state of charge. If that rate is more than the battery’s natural absorption rate at full charge, the electrolyte will begin to break down and boil away. Many a rider has stored a bike all winter on a trickle charger only to find the battery virtually empty in the spring. Also, since charging tends to oxidize the positive plates, continued overcharging can corrode the plates or connectors till they weaken and break.
A battery only requires a little monthly maintenance to perform perfectly. Keep the battery charged to 100%, recharging when the lights dim, the starter sounds weak, or the battery hasn’t been used in more than two weeks. Other than that, follow this simple check list every month:
- Check the electrolyte level
- Top up only with distilled or deionized water, wear gloves and protective glasses.
- Top up in a well ventilated area, Beware of fumes.
- Keep the top free of grime
- Check cables, clamps, and case for obvious damage or loose connections
- Clean terminals and connectors as necessary
- Check inside for excessive sediment, sulfation or mossing
- Make sure the exhaust tube is free of kinks and clogs
- Replace caps firmly
- Finish up by testing the battery with either a hydrometer or voltmeter. To extend the service life of your battery, make monthly battery maintenance part of your routine.
- Use only distilled or deionized water, NOT tap water. Tap water has minerals in it that will not do the battery any good.
- Storage can be hard on batteries. In fact, non-use can leave them unable to hold a charge.
- Store your bike in a place that is always warmer than 32 degrees. If your bike is outside remove the battery from your bike and store it in a location that is always warmer than 32 degrees. This will insure that your battery does not freeze and crack.
- If you remove the battery from your bike DO NOT store it on a concrete or metal surface, place the battery on a wood or other non-conductive surface. Batteries stored on concrete or metal will discharge over time.
- Place a charger on your battery. Trickle charge your battery at least once a month. A battery that is fully charged will have a longer life and is less likely to freeze during cold winter weather.