Here come a display of ignorance. lol   Lately i've been dealing with vertigo issues, and cannot ride my bike.  That being said, I don't want to just let it set without ever running it.  This led me to a question.....

Does the battery get charged as the bike is running, or does it have to be driving?  I'm assuming it is charging as it's running, but I know they don't have an alternator like a car, so it's more of a maintenance charge.  I don't really know much at all about the charging system on bikes.  This is my first.  Anyone care to take me to school on this?  I didn't find any posts on here that answered my question.

Thanks!

Bike running would just be sitting there running, but not going anywhere.

Bike driving, would naturally be if you are riding it somewhere.

Basically I just want to keep everything "fresh" on the bike while it sits for awhile until I can get my health issues fixed, and go ride again.  Thinking of this made me wonder about the charging system, and I realize I don't really know how it works.  This is my first bike.  I know cars quite well, but when it comes to bikes, it's all new to me.

Thanks.

Once the engine is a bit above an idle, the electrical system will charge the battery. It doesn't care whether the bike moves or not. This is exactly the same as with a car, although the control circuitry differs. And it is not just a "maintenance charge" as the system can supply several amps to the battery However, if just keeping the battery charged is the objective, you will be better served to get an automatic battery charger such as the Battery Tender and charge the battery with that. Find a charger with a maximum charge rate of no more than two amps. If you have a charger with variable rates set it to the lowest.

There is some dispute over the wisdom of starting the engine for a few minutes every week or two to "keep the battery charged." I personally believe if you are not going to ride the bike for at least several miles you are wiser not to start it at all. Starting it and letting it run idle (not under load) does not get it evenly warmed, and tends to accumulate water in the oil and the exhaust system.

I strongly recommend a float charger, rather than a trickle charger.  

The float charger senses the state of charge in the battery and adjusts the amperage accordingly, eventually shutting off at a full charge, maybe at 13.8 volts, then turning it back on when the voltage decrease a few tenths.

A trickle charger is just a low amp constant voltage (maybe 14.4 volts) charger that over a long time (months) will sulphate the plates inside a lead-acid battery.  

Float chargers are good for long-term, unattended battery storage, UPSs, alarms, etc.

Trickle chargers are cheaper, but you'd want to make sure they didn't stay hooked up very long, especially on the typically small motorcycle battery.

bill67 wrote on 09/09/12 at 13:36:38:

Bill, are you suggesting the removal of the battery before/after the 2 amp overnight charge?  If the battery is fully charged and connected to the motorcycle, are you suggesting it will NOT discharge for 4 months? Oh, and why wouldn't you start it at all while it sits?

bill67 wrote on 09/09/12 at 17:59:00:

Guess you never heard of the inherent self discharge rate of pretty much all battery chemistries.  AGM is about 1% to 3% per month and SLA are from about 1% to 5% per month.   AGM batteries do much better at storage then SLA batteries.  SLA batteries will need a topping charge every so often to keep the plates from Sulfation  where as AGM batteries don't have this issue but you still should either keep them on float charge or check it every now and then and recharge once the battery drops to about 70% charge state.

Here is an article from battery university on proper storage of batteries.

http://batteryuniversity.com/learn/article/how_to_store_batteries

R.F.

Sounds good.  Everyone, thank you for the info.

We talk of trickle chargers verses float/maintainer chargers,.......

In reality, I don't believe you can buy any small 1-2 amp trickle charger that is not a maintainer/float charger,....one that is not designed to leave on a battery all the time,....nor has any been on the market in at least 10 yrs.
If you are not sure of your older charger, trickle or float, just check the finish voltage,....it must not exceed 13.2-4 maximum (in warmer weather) If it exceeds this voltage, it is not a maintainer/float charger, and should not be left connected for more than 24 hrs, or it will cause gassing, and will loose water rapidly.

Note:
in cold weather, a float voltage of 14 and more can be used w/o gassing.
That is why in a perfect world, all of our chargers would be temperature regulated, making for very expensive chargers.

A lead acid battery should be charged every 30 days, or left on a float charger.... if you want the longest life out of it (no matter what Bill thinks)