Can a bad Stator cause battery failure?

[Quack]

There are so many knowlegable folks on this board, so I pose this question. I think I know the answer, but.....

The stator on my bike went bad and it has since been replaced. 4 days after I got it back, the battery went dead. The shop charged the battery and it held a charge (for over a week now it has been sitting in their shop), but no one there can explain why the battery lost its charge.

The battery also went dead just before I took it to the shop (which resulted in them replacing the stator). The bike ran fine with the new stator for about 150 miles...when I went to start it the next day, all lights and gauges went dark the second I engaged the starter. So I am wondering if a bad stator can cause a battery to fail. Can a bad battery hold a charge for months (when the bike is not being ridden) and then be drained by riding it for 4 hours?

This is an 06 Classic 900...no electrical modifications other than replacing the horn with a Fiaam 80.

[loki333]

Well, generally speaking, the battery should hold a charge for quite a while.
But that depends on the demands on it, and how its charged of course.
Im not sure about the new gel type batteries, but the lead acid ones have to be checked monthly, or every 500 miles.

So, I'd think that yes, the faulty stator would perhaps cause the battery to either not receive as much charge as it needs, or receive too much charge.
Either will result in the battery becoming damaged over long period.

Also, keeping the battery in a disused state can also screw up the battery.

There are chargers out there that just plug into the wall from the bike, and are supposed to monitor the battery and keep it topped up when not in use.
But i dont like these myself as i hear a lot of negativity about them.

I just take off the battery to charge it, and have resistors on the charger to reduce the current to a trickle-charge to get the maximum possible life out of the battery, as well as have made my own regulator which works better than the original.

Really, as long as your regulator and generator are working ok, and as long as u at least go for a long ride once a fortnight and least start up once a week, and check battery fluid levels (where applicable), then theres no reason that the battery should die on ya.

Anyways, hope this helps in some way

JT

[RichLockyer]

Every time a battery is deep cycled, it can lose up to 20% of it's capacity.
Personally, if my bike fails to start twice due to a dead battery (whether it's from sitting in storage or leaving a light on) I replace the battery.

A healthy battery in normal temperature conditions SHOULD hold a charge strong enough to start a bike and avoid damage to the battery for at least 60-90 days. Over 90 days, it's a crapshoot.

[loki333]

Yeah, that sounds about right.

I dun think i could afford to keep replacing batteries tho.

I just take battery off if i know i not gonna use bike for a while and discharge/ charge it now and again just to get the whole use out of it.

[RichLockyer]

Yeah, that sounds about right.

I dun think i could afford to keep replacing batteries tho.

I just take battery off if i know i not gonna use bike for a while and discharge/ charge it now and again just to get the whole use out of it.

+1

But that is one of the danger of a Battery Tender, especially when used daily. They keep the battery up and may mask any deficiencies in the charging system... which will then rear their ugly heads on day 2 of a 3000 mile road trip

[N3FOLN3FOL]

That is the end result of a bad stator. When I had my 900, the stator was identified as 'bad' due to a weak and dying battery. Both the stator and battery were replaced under warranty. If your stator was replaced under warranty, your battery should be replaced as well.

[Quack]

Thank you all for your replies. I have been told that the battery was my responsibility to replace even though the stator was litterly melted by the dealership. The bike has been in the shop for 13 weeks now...11 weeks to replace a stator (it was on back order), and now 13 days trying to figure out why the battery went dead. I'm a little flustered.

At least they have protected me from getting sunburned in this lovely fall weather.

[Ride4Life]

Can a stator damage a battery??? prolly not

Can a weak battery damage that shiney new stator???? yes!!!!!!!

[Kebo]

Can a stator damage a battery??? prolly not

Can a weak battery damage that shiney new stator???? yes!!!!!!!

I would have to disagree. As I speak from experience, I had 2 bad stators kill 2 batteries in a fairly short amount of time. It's a long story on the stators, but two years in a row I had stator problems that killed my batteries.

[Baitis]

Rectifiers kill batteries. If the rectifier is shot it can send AC voltage to the battery. It can also trash a stator. If the rectifier is internal to the stator it makes troubleshooting easier. Since charging circuits generate AC voltage the whole system needs to be checked for damage before turning the key. A battery in good condition can have a bad cell and still run an engine if it's not shorted. I haven't dug that far into my manual yet to see what the test looks like but it's a simple diode test to find a bad rectifier.