Battery power

hi guys any idea how much power can I draw safely without draining the battery while the motorcycle is running? How do I measure it. I plan to put on accessories and wonder this will kill the batt. any guidelines or tools I can use to measure it?

thanks.
Chee

A list of what accessories you put on would be helpful. The bike produces more electrical power at higher RPMs so you may be at a state of discharge at idle and fine when cruising. I have a garmin and heated grips and my voltage indicator says everything is ok.

The alternator produces 420 watts at 5,000 rpm, however you will not likely be running there very often. I think if you add significant optional power demand, you should have a voltage monitoring solution. I normally use a digital voltmeter, but on this bike I wanted to keep it simple, so I used a multi-color LED voltage indicator...

Clearwater Voltage Sentry (CVS) Battery Monitoring Device



There are simpler methods that offer less information and meters that give you the whole story, but I like this solution as somewhere in-between the extremes. But something is necessary. You have options about what you run. It is OK to have more equipment than you can run simultaneously as long as you stay within the battery's charging capability at the speeds you are running. I can remember on my old Airhead BMW with a 280 watt charging system that I could choose between my headlight and my heated jacket. I can remember once riding at night in 25 F weather and modulating the current to my jacket in order to maintain 12.5 volts. I wanted more, but it wasn't there. The moral of the story is that you need to know which side of break-even you are on...

[video=youtube_share;WGPMadwqPKQ]http://youtu.be/WGPMadwqPKQ[/video]

Great post, thanks Lee!

I knew if anyone had the answer it would be Lee. It's a good thing we have him around.

gkgeiger said:

I knew if anyone had the answer it would be Lee. It's a good thing we have him around.

Click to expand...

I can't agree more. We must invent a title for this guy, he's the master and always willing to help

duk2n said:

I can't agree more. We must invent a title for this guy, he's the master and always willing to help

Click to expand...

The NC Guru would seem appropiate

Shucks guys. Cut it out.

How about the One Eyed King?

Thanks Lee! That YouTube is hilarious! I now understand. I already have GPS/ heated grips/ 12V 1A plug/ and I plan to:

1 light up the storage area and
2. maybe install fog lamp,
3. heated jacket and gloves liner plus
4. LED light for the wheels


gpd211, How do you measure the power draw? Does the voltmeter (I presumed) indicate certain voltage that indicate it is OK? Where do you plug in to measure. Sorry I am very dumb in electrical.

Ideally the voltage should be taken at the battery terminals. The CVS unit I am using does so. It turns itself off if there is no activity for 5 minutes. If you take the voltage at other places you may have voltage drop that would confuse your reading. A fully charged battery should read about 12.6 volts. When the engine is running, the alternator should increase the system voltage to at least 13.2 volts to charge the battery. If the alternator cannot hold this voltage or higher, then you are either overdrawing the system, or the charging system is not working properly. If the situation is allowed to continue, the battery will become discharged to the point that it will not start the bike.