86 Big Red 250ES Battery Drain

[vwalleyes]

Hi, Been having problems with the battery on my Big Red for a while. I have a brand new fully charged battery in it now, the starter turns over & starts great. If it is left for a few days the battery is dead, no crank. Starts OK by kick start. Im assuming that there is a short somewhere in the electrical system which is discharging the battery.

Any ideas on where to start looking?

Thanks!

Tom in MN

[Oldshell4481]

may sound dumb but did you leave your light or key on?? is there enough acid in your battery to hold a charge?

[mikey's250sx]

if you leave it in neutral won't the neutral light also stay on?

[Oldshell4481]

yeah if the key is left on

[vwalleyes]

When the key is turned off the neutral light shuts off, I always take out the key. And yes there is enough acid in the battery, it is brand new.

[Oldshell4481]

brand new batteries dont come full, you need to fill them, so if you didnt fill it it wont hold a charge for very long.

[vwalleyes]

When I brought home the new battery I filled it with acid, charged, and now its in the bike. It started great. Sits for a few days, dead battery. Charge it up again, same thing. I don't think its a battery problem, its new.

I checked wires today, could not find any obvious shorting problems. Can anything like a coil or voltage regulator or stator go bad & drain the battery?

Thanks

[ATCnut]

There are any number of places that can be causing your problem. The way I troubleshoot these problems is to put a current meter in series with the battery, which will show that current is flowing and drawing the battery down. Then, using the wiring diagram as a map, I disconnect wires until I find the path the current is taking. This will lead you to the problem.

[vwalleyes]

Thanks ATCNut,

I'll give that a try. Too bad I put the current meter in parallel with the battery. Need to buy fuses. I am just a simple mechanical engineer. All I know about electricity is to not let the smoke out...

[ATCnut]

Welcome

I'm an electrical engineer. That just means when I blow the fuse on the meter I should know better . lol