Charging problems

[jorge lobo]

Hello XS lovers
I'm back with my battery not charging
Now I noticed that the charging sistem is ok when bike is in Idle but when I engage the bike to drive it the battery is gone in a few minutes
Any ideas of what may be wrong
Already check conections and de magneto

[tinman905]

Have your battery tested . It is most likely shot if it isn't holding a charge.

[natemoen]

Does the battery actually drain to nothing / how long does it take?

You say you checked connections but did you check them all, headlight to tailight, clean Nd fill them with dielecteic greas?

What are you voltage readings at idle and then also at 4000 rpms?

[cywelchjr]

That's a good operative piece. The charging cannot be good at "idle" on these bikes without running a high idle AND one of geezers regulators. So, that "good at idle" is probably bad, and the system is probably not putting out anything at all (or very little). Since requirements increase with engine speed, the battery would of course drain much faster when riding (plus brake light etc).

[jorge lobo]

Well I did check 90%of the connection, the battery is brand new
When in Idle will read 15.5 V when at 4000 rpm at the begging reads 18.60V and once steady reads 17-17.6V

[cywelchjr]

Well I did check 90%of the connection, the battery is brand new
When in Idle will read 15.5 V when at 4000 rpm at the begging reads 18.60V and once steady reads 17-17.6V

There is either something BAD wrong with your charging system and your battery will be toast soon, or there is something wrong with your meter. Those readings are WAY out of whack, and point to something really bad wrong.

Normally the voltage would read at or maybe even slightly below when at idle, and then rise to 14.5 to 14.8. Anything higher than that WILL boil the battery to death, anything less and it's not going to charge. And AFAIK based on experience, either one will cause problems. However, it shouldn't be possible to get 15v at idle, the system just is not capable of generating that voltage at anything less than 1400 RPM, and in most cases needs a little more than that even so.

[jorge lobo]

Ok I will have to open the new tester do you thing that maybe the voltmregulator is fry

[natemoen]

Could you post a picture of your reegulator/rectifier? Never know maybe a PO has.done something......clever.

[natemoen]

Oh and what is your idle at?

[jorge lobo]

The idle is 800-1000rpm

[jorge lobo]

Could you post a picture of your reegulator/rectifier? Never know maybe a PO has.done something......clever.

Well it look good and the original but I'll try to get one

[cywelchjr]

Well it look good and the original but I'll try to get one

First is to make sure your getting a good test. Those readings are WAY high for that idle speed, which points to the tester.

You say it's a new battery, did you charge it for at least several hours before putting it into service? They don't come with a full charge, only about 80% and need a charge put on them before being put into service. But step one is to insure that you are getting true accurate voltage readings when testing, then you can go from there.

Can you try the tester on a known good system (such as a car)? Voltages should be similar, but cars will give pretty much full voltage at idle unlike a bike.

[Incubus]

I cannot explain that idle reading. Cy is right; it is way too high.

I got running readings like those when I first got Incubus running last year. In my case, it was a bad reg/rec. They can go bad and allow the alternator to charge too high, as well as go bad and constrict current flow.

That's where I would look (after I checked my tester).

Patrick

[jorge lobo]

What is the best way to test the reg/ rectifier

[DAVINCI]

The best way(s) are described above. Have you checked the alternator case to see if there is a magnetic field there when the key is on? A small paper clip should be attracted to it when the key is on. One other way is to unplug it and then start. You should get a below 12v reading at the battery. That would prove that either the reg is toast OR you have a short to ground on the green wire. Then check the green on the harness for a short to ground. If no short, replace the reg.