Battery draining when bike off?!?!?!

[IcyHotUrBeanBag]

Hey forum friends, I tried to start my bike one day and because it was flooded it wouldn't and the battery drained. I pop started it and ran it around for a while then stopped and went to class. When I went out to start it the battery was completely dead. I get that. The battery was only 2 months old so I brought it to the battery shop and had them check it with a volt meter. With my manual on hand we checked the readings. One problem though, I forgot to turn on my headlight for the tests. Anyway, on idle the battery was somewhere around 13.5. Around 2,000 rpm it read around 16+. The book says to change the regulator/rectifier which I am going to do. One question though. After riding the two miles to the battery shop my previous dead battery had held a charge, after I turned it off, for about 5 minutes at the battery shop. After hours it was dead again. How does a battery lose a charge when the bike is turned off?

[mike10]

short

Short in the electrical system. I had a bad turn signal switch. Over a few days it would drain the battery.

[Killer2600]

Hey forum friends, I tried to start my bike one day and because it was flooded it wouldn't and the battery drained. I pop started it and ran it around for a while then stopped and went to class. When I went out to start it the battery was completely dead. I get that. The battery was only 2 months old so I brought it to the battery shop and had them check it with a volt meter. With my manual on hand we checked the readings. One problem though, I forgot to turn on my headlight for the tests. Anyway, on idle the battery was somewhere around 13.5. Around 2,000 rpm it read around 16+. The book says to change the regulator/rectifier which I am going to do. One question though. After riding the two miles to the battery shop my previous dead battery had held a charge, after I turned it off, for about 5 minutes at the battery shop. After hours it was dead again. How does a battery lose a charge when the bike is turned off?

5 mins is not enough time to charge a dead battery, it'll only put a surface charge on it which will disappear with ease.

16+ volts charging is enough to cook a battery if given the time to do so, after replacing the R/R you may find your battery is bad. What I would do is charge the battery with a battery charger and once fully charged, unhook the charger and see if it self-discharges to below 12.6v overnight. A two month old battery should not.

There is also the possibility of a parasitic drain on the battery when the bike isn't running, something that shouldn't is drawing power.

In any case fun stuff, so prepare for fun

[tom203]

Short in the electrical system. I had a bad turn signal switch. Over a few days it would drain the battery.

Yes, might even be the R/R itself sucking the life out of battery.

[IcyHotUrBeanBag]

no kidding, good to know.

[IcyHotUrBeanBag]

What is the best way to find a short

[IcyHotUrBeanBag]

Short in the electrical system. I had a bad turn signal switch. Over a few days it would drain the battery.

I am brand new to electrical. If the bike is off, how does a short or bad switch drain the battery? I assumed if no electrical components are on when I turn the bike off the battery is not being used.

[IcyHotUrBeanBag]

Ok, so hopefully when I change the R/R things will work out.

[tkent02]

The charging system is still connected to the battery, but current does not flow because of the diodes in the rectifier, which act like check valves. If the diodes go bad, you have a small short.

You could disconnect the regulator wires while it's parked to see if it stops the battery from discharging.