Battery keeps dying

[bvailette]

Edit: Bike is a 1980 gs450

So I did the quick test on my battery and got these results

Key off - 13.35
Key on - 12.8
Idle - 15.2
2500 - 16
5000 - 16.56
Key off - 14.2

My problem is i take the battery full out and recharge it upstairs on a charger. Ill put the battery "it's about 2 months old" into the bike and after a few hours of riding and turning the bike off and on I notice the neutral indicator will start dimming a little. A couple more starts and stops later there is nothing. The battery isn't strong enough to start the bike and needs to be recharged. Ive had the battery integrity tested twice at advanced auto parts and both times its come back "Good but needs a recharge"

So with that all being said I'm just at a loss. The one thing that i will say the guy at the store recommended me this battery After looking over amazon and a few online part stores they recommend this battery They're different and also the reason I changed my old battery out was because I left my bike "on" for a few hours by accident at the house and the lights drained it to death

[chuck hahn]

its OVER charging and cooked the battery from the inside out. rectifier / regulator is toast.

[chuck hahn]

What bike is this???

[bvailette]

Sorry after all the I still forgot something, The bike is a 1980 gs450ET

[Guest]

Sorry after all the I still forgot something, The bike is a 1980 gs450ET

What Chuck said. Get yourself a good multimeter and get to testing. Bet you find your stator is about fried as well.

[posplayr]

No reason to suspect the stator but as chuck said the r/r is toast and your battery is probably boiled out. Try adding water and see if you can recover it.

[Guest]

If it has boiled out and is not damaged too much just fill it with distilled water, it should bounce back after a little while, but the overcharging will damage the stator if it has been going on for long. The R/R doesn't ever overcharge if it works properly so that is definitely toast and should be replaced before further damage occurs. If the stator checks out after R/R replacement (a series R/R recommended), you should be prepared for it to fail down the road. Mine lasted another year before it gave up after the regulator failed and the battery boiled out.

[chuck hahn]

I didnt see a manual at Bikecliff for that bike, so maybe someone has a link??

[Steve]

I didnt see a manual at Bikecliff for that bike, so maybe someone has a link??

Center column, third from the top: GS400-450 '77-'87.

.

[chuck hahn]

My day to be so tired I cant read Steve!!! HA HA

[posplayr]

If it has boiled out and is not damaged too much just fill it with distilled water, it should bounce back after a little while, but the overcharging will damage the stator if it has been going on for long. The R/R doesn't ever overcharge if it works properly so that is definitely toast and should be replaced before further damage occurs. If the stator checks out after R/R replacement (a series R/R recommended), you should be prepared for it to fail down the road. Mine lasted another year before it gave up after the regulator failed and the battery boiled out.

Why does overcharging damage the stator?

[tom203]

Why does overcharging damage the stator?

It runs wild uncontrollably - sorta like a car on downhill with no brakes!

[posplayr]

It runs wild uncontrollably - sorta like a car on downhill with no brakes!

Say the R/R regulation is gone and the R/R is just regulating three phase. All of the output power is either going to the system or the battery. If the R/R were to regulate, we already know that the stator current will rise putting more stress on the stator.No regulation the current drops back to the load currents.

If there were a series R/R , then we know the regulation stator current is always just the load current.

I just don't see where the stator is more likely to be damaged under non-regulation. It is the shunt regulation that kills it, removing shunt control improves things for the stator, al though it is worse on the rest of the electrical including the battery.

[Guest]

I may be wrong. The regulators on my '78 and the '79 parts bike both failed by overcharging and boiling the battery out. When the one on the '78 failed I replaced it with the one on the '79 until it boiled my battery dry again also about six months later. When I went to use the stator in the '79 parts bike before ordering a new stator when it failed a year after the Compu-Fire installation, it turned out to be in worse looking shape than the one I took out of the '78. I don't know the history of the '79 except it only had about 5,400 miles on it when I got it, so I made the assumption the regulators had caused the damage in both cases. No scientific evidence. It could have been the regulator on the '79 had failed and was replaced, but the stator was already fried, and got parked at that low mileage. I'm sure you have a reason for questioning me, just going on cause and apparent effect.

[posplayr]

I may be wrong. The regulators on my '78 and the '79 parts bike both failed by overcharging and boiling the battery out. When the one on the '78 failed I replaced it with the one on the '79 until it boiled my battery dry again also about six months later. When I went to use the stator in the '79 parts bike before ordering a new stator when it failed a year after the Compu-Fire installation, it turned out to be in worse looking shape than the one I took out of the '78. I don't know the history of the '79 except it only had about 5,400 miles on it when I got it, so I made the assumption the regulators had caused the damage in both cases. No scientific evidence. It could have been the regulator on the '79 had failed and was replaced, but the stator was already fried, and got parked at that low mileage. I'm sure you have a reason for questioning me, just going on cause and apparent effect.

Well, that is clearly quite possible. If it was the stress on the stator and R/R that cause the R/R to fail first then, then it would be logical to suspect damage to the stator as well leading up the the R/R failure.

I was thinking that the R/R failure might have been sporadic, of randomly induced in which case there would be no reason to believe in stator failure. I guess it must be it is far more likely that dirty connections can cause the R/R to increase it's shunting, driving up the failure probability for both stator and R/R. It is not random but as inevitable as entropy.