Hello all,

Another question for those that know more than I. I went too go for a ride today and had too jump start the bike, damn battery was dead. It has only sat for 48 hours, I thought that maybe I had left the ignition on but once I got the bike started I noticed that at 800 rpm (idle) i was only putting out about 11 volts, once I started riding and was turning about 2k rpm it was up too almost 14 volts and stayed there for a bit. I was curious if the charging system is supposed too work like a normal one, 12.5 volts at idle and 13.5 above Idle. Oh yeah this is on a 2001 FLHT.


Thank You,
Chris

 

If you're looking at a gauge on the bike they are not very accurate. With a multi-meter you should see around 14.6 volts at the battery with the engine running at highway speeds. If you are not getting those numbers you may simply have a poor ground or other connector in the charging circuit. Start with the big cables at the battery and check each end of both, for cleanliness and tightness. Check your ground cable from engine to frame.

 

Yes grbrown is on the right track, but my question is how old is your battery? ?

 

If all the wires are good, check the voltage regulator.

 

Thank you guys. The dealer told me the battery was brand new. I rode it last night and this afternoon the battery was dead. It is something that happened overnight. Just started doing this. What should the voltage be at idle? I know that the gauge says at first start with the jump start it was up too almost 14 volts at 1200 rpm. But after riding it for about 15 minutes it went down too about 12.5 volts. That is on the gauge on the Dash panel. I just checked the charging system with my DVM and at about 2500 rpm the voltage is about 13.2, also the battery was down too 11.75 volts, I am charging the battery up over night and will check all of the connections in the morning and see what I come up with. Hopefully if it is the charging system the dealer will do something for me seeing as how I bought the bike this past Sunday. They did mention that the give a 30 day warranty so maybe at this point the best thing I can do is call them and see what they can do for me. Thanks for all the help guys. It is much appreciated.

Chris

 

Hello again,
Another update to the above. Last night when I got home I decided too put the battery on the charger and give it a real good charge. That was about 530 pm and let it charge in the bike until about 8ish when I checked it and noticed that the battery was getting really hot. I disconnected the charge for about 2 hours too let it cool down. I went out again about 10:00 and decided too pull the battery out of the bike and charge it on the ground. I got up around 6:30 this morning and the battery was quite warm too the touch. When I hooked the battery up originally too the charger it was pulling about 8.5 amps on the charger and this morning after about 8 hours of constant charging the battery was still pulling 6.5 amps on the charger. I put my meter on the battery and it read 12.75 volts. So I figured I would use my load tester on the battery and it tested good. Granted it is an older tester and it will not test for a bad cell or a shorted cell. If the battery is dead than this will explain why the dead battery over night.

Thank you for reading
Chris

 

sounds like a bad cell, i had a new battery that only lasted about a month, took it in and they did a load test and it was bad, but they did say there were having some problems with there battery's, so they were told by MOCO to charge them first then do a load test. before they let the bike go out. to make sure.

 

Sounds like you are using a car battery charger which can ruin a MC battery. The most a MC battery should be charged with is 1.5 amps. Also if you jumped it from a car battery and left in on too long you can damage the battery. I'm a firm believer in the Battery Tender Plus which has a chip that monotors the battery and keeps it fully charged. Some of the cheap trickle chargers will only bring battery up to 80-85 % of full charge on these sealed batteries.

If you still have problems after you get a good battery I'd say you have a wire grounding out against the frame, could be anywhere. Try lightly touching your frame and see if you get a tingle.

 

That's news to me. I think you're mistaken about that. The alternators on these bikes put out way more than 1.5 amps when the battery is low.

 

Well maybe you should check with the HD dealer to see what they use and why!