Honda Rubicon battery issues

[JacobSlabach]

Theres a horse farm I work/worked at and they have a Rubicon (500cc)  think its a 04.  Its been having starting issues.  First time it wouldnt start, the owner said it had a new battery in it (this is about a year ago I guess..).  I replaced the solenoid and then the starter.  the battery was dead so I jumped it and then it started fine after the battery charged.  about a month later, same problem.  I swapped the solenoid back out with the old one(still had it)- nothing.  the owner had another battery she said was good, swapped that out and it fired up.  Now, today, same problem again... owner says the starter was sluggish and then the battery went dead.  Went out and jumped it again and it ran fine (its a carburated atv so its not fond of under freezing temperatures...).  the stater is working cause when I got there, the battery had 7-9v on it (multimeter said it was rising and falling (with the key on)).  I jumped it off  our van and rode it around for say 5-10mins.  when I shut it off again, battery is reading 14v with key off and 13v with it on.  thats as far as I've gotten..  I asked the owner to let me know if anything else happened later on..  What I'm wondering is if its just the battery, or maybe is the regulator rectifier not working letting the battery be overcharged cause it to die?  And then again, the bike could have sat with the key and headlight on overnight for all I know..

[Frank Angerano]

There could be something that’s drawing off the battery with the key off.  Maybe a light of some sort or maybe a switch for something that was put on after.  Also a relay that could be stuck.  You can check this like you would do on a car.  Make sure the battery is charged and has 12 volts.  Disconnect the positive cable. Take a test light and attach the alagator clip on the test light and attach it to the positive cable and take the point of the test light and touch the positive terminal of the battery.  Make sure the key is off.  If the test light lights up there is a draw on the battery. I leave the test light on and start pulling fuses or plugs until the light shuts down.  That narrows your draw to the fuse that you pull that shuts the light off. 

Edited February 1, 2019 by Frank Angerano

[JacobSlabach]

everything is still stock on the bike... not even a winch or anything..  I think someone just left the key on with the headlight, because when I got there and turned it on, the headlight came on.

[David Peterson]

Your battery could also be weak. How long did you wait before checking the voltage? Usually wait about 1 to 2 hours and check the voltage again disconnected.  You can also check the battery for a weak cell with your volt meter. Do this carefully and safely. Remove the caps, negative meter lead to negative post. Take the positive lead and slowly put it in that cell. DON'T FORCE IT IN. You just want to get it in the acid. Check your readings. If all cells are about the same then the battery is ok, If you have one cell thats shows a real low voltage that's usually a bad cell.

A light coating of regular grease on the battery terminals helps prevent corrosion, makes using the screws a lot easier to remove too. old time trick

Battery's that sit for long periods of time develop a memory and won't fully charge. Get a good battery charger that desulfides the battery. Put it on for 24 hours and that will remove the battery's memory. I use one myself and once a year I put it on our battery's and leave it for 24 to 36 hours. I haven't had to buy a battery in quite a mumber of years, We have battery's all over in lawn and garden, atv, vehicles and gate opener's. 

 

[lemoncap]

Could be a leaky magneto too

[JacobSlabach]

so sorry I never concluded this thread!  Someone had left the lights on (probably one of the kids that runs it around the farm..)  but thanks to all who contributed!  I learned a thing or two from you.