Electrical Power Sources on a Motorcycle
Very simply said, there are two Power sources on your motorcycle:
Stored electricity in your battery (DC or Direct Current)
You can define a few different types of Batteries:
- The oldest is the conventional battery or Wet Cell. Easily recognizable by it’s vent tube (on motorcycles), vented caps on cars (no longer in use for cars). This battery must be maintained on a regular basis, by topping off the electrolyte with distilled water. The voltage or potential difference for a fully charged conventional battery should be between 12.4V and 12.8V. To measure the voltage of a battery, simply set a multimeter in Volts DV and put the black probe on the negative, and the red probe on the positive of the battery.
- Then came the Maintenance Free battery whose voltage should be fully charged 12.6-13.2V. By it’s name this battery is somewhat Maintenance Free. I say somewhat because part of maintaining a battery consists of keeping the posts clean (no corrosion or sulfate); and recharging is what not in use. But NEVER add any liquid to it.. Matter of fact, if the battery has been correctly prepared by your seller, it shouldn’t have any liquid.
- Then Harley Davidson & GM created the Absorbed Glass Mat battery. Also a maintenance free battery, with the added plus, that it can be shipped without any type of warning labels, because it doesn’t have any spill-able corrosive agent. The voltage for a fully charged one is 12.9-13.2V.
- And the latest (as of 2010) is the Gel battery, a combo of MF & AGM. No liquid. Voltage fully charged: 12.8-13.2V (same as an AGM).
Generated electricity, produced by an Alternator type device, creating Alternating Current of AC
There are different types of those electricity generation devices:
- One commonly called and Alternator. This what you find on most cars, and only a few models of motorcycles. This system cannot function without a charged Battery connected to it. Just like the ones on cars, all the components are in one part called an Alternator. You can find those on some older models Yamaha, a few more recent Kawasaki’s, a few large models Suzuki’s. Used mostly on some touring models, and not on Sportbikes.
- Then a similar one in concept but different in it’s construction. Honda uses this type similar to an Alternator, but where the components are not all included in one device. The true name of this concept is Electromagnetic System.
- Finally, the most common system is the Permanent Magnet System. Which in turn has 3 different types defined by the number of coils used: 1/2 wave; Full wave (was a favorite for most Harley Davidson models, and still in use on most); and 3 phase. Suzuki has implemented on called Center Tap of a fourth phase.
Now, all of the ones described above have the purpose of keeping the battery in a good state of charge, while the engine is running.
- Then you have the various generation devices for the purpose of ignition or creating a spark in the combustion chamber. I will address those at a later date.