Battery not charging

[chadwikket]

Last fall while driving my 81 gs650g to storage the lights slowly dimmed until eventually there wasn't enough power to sustain motion. (aka the bike died in the middle of an intersection.

The bike has always had trouble starting, and has kind of always had a problem keeping the battery charged. The battery was new last year.

I don't really have any experience with electrical work on a bike. I do have access to a multi reader.

Any help would be mighty fine.

[Big T]

Read the Stator Papers on the main page and test away

[Buffalo Bill]

Easy things first.

I found out the expensive way my bike had a bad ground from the regulator/rectifier ground (black wire) to the battery neg-. I ran a wire from the one to the other and then it charged good. I had to buy and install a $200 stator to find out all I needed was piece of scrap wire.
You can easily tell if the bike is generating by shining the headlight beam on a wall and watching if it gets brighter when you rev up the rpms.
If your battery boils away it's water, it's the regulator/rectifier.
If you just get no charge after you're sure the connections are good, its the stator.
The Stator Papers on this site tell you how to test the components, it's not too tough. Replacing the components is not too tough either.
Best O' Luck!

[chadwikket]

I will check it out. I'll keep you posted.

Thanks for the help!

[spyug]

Welcome aboard.

Common problem with these old beauties. As the guys said try the extra ground from the R/R directly to the battery first. That sorted it for me to. If that doesn't improve the situation then read and follow all the tests in the Stator Papers.

In addition to weak R/Rs and stators, corroded connectors are a big problem. You should go through the bike and clean up all connectors. Too many to do at one fell swoop so do a few ( starting at the battery and fuse block) at a time. The switch controls on handlebars often get gunked up as well so you should carefully take them apart and clean them up.

Another problem is bad grounds so pay particular attention to making sure your grounds terminate at clean metal to metal joints.

You may have boogered the battery so you might want to get it load tested and perhaps re-filled.

Good luck with it.

Cheers,
Spyug

[chadwikket]

I have done the tests in my manual.

The voltage of the battery while at 5000 RPM is 12.7 DC volts. The manual says that it needs to be at least 14.5 volts.

After that I removed the seat and tested the three connections it specified. The readings were 65 +-, 65 +-, and 72 +- AC volts. The manual claimed they needed to be 80.

I have yet to check the grounds and the connectors. I will do that soon.

Thanks for the help.

[Nessism]

I have done the tests in my manual.

The voltage of the battery while at 5000 RPM is 12.7 DC volts. The manual says that it needs to be at least 14.5 volts.

After that I removed the seat and tested the three connections it specified. The readings were 65 +-, 65 +-, and 72 +- AC volts. The manual claimed they needed to be 80.

I have yet to check the grounds and the connectors. I will do that soon.

Thanks for the help.

Your voltages are fine. Problem is your R/R or the ground wire. As stated by the others, extend your ground loop to run to the battery. That fixes the problem quite often. If you need a new R/R, there are lots of low cost solutions. Do a search for tons of info. I'm running a late model CBR R/R I bought off ebay for $25.

[posplayr]

Could also be the positive lead going through the fuse box. Measure the following voltages.

1.) R/R (+) to Battery (+) at 4000 RPM should be 0.25V no more that 0.5V


2.) R/R (-) to Battery (-) at 4000 RPM should be 0.25V no more that 0.5V

#1 will fail is there is excessive corrosion and resistance in the fuse box.
#2 is an issue with corrosion on the battery grounds

[chadwikket]

I'll check it out.

Thanks for the Info!

[BassCliff]

Hi Mr. chadwikket,

Sorry I'm late to the party. Be sure that evey electrical connection and ground on the entire wiring harness from headlight bucket to tail light is clean and free of corrosion, including the fusebox and ignition switch. This will save you headaches in the future. Ask me how I know. Please check my website for more stator/regulator information.

Now let me roll out the welcome mat for you...

Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff