Max Charge 13.8

[Guest]

Looks like I'm maxing out at about 13.8 volts at 4000rpm. Good enough?

Thanks!

[posplayr]

Looks like I'm maxing out at about 13.8 volts at 4000rpm. Good enough?

Thanks!

If you look at the quick test diagnostics you will see it is too low; clean connectors between battery and R/R.

[snackie]

Yeah, I've read the quick test. Just wanted to see if folks thought 13.8V was good enough. thanks.

[quexpress]

If you look at the quick test diagnostics you will see it is too low; clean connectors between battery and R/R.

Is this test applicable to GS only, or to any make/model of motorcycle?

[posplayr]

Is this test applicable to GS only, or to any make/model of motorcycle?

I would not call all of the quick test results to be universal truths, but I would guess most of the older carburated UJM's are going to be similar

[chuck hahn]

I think the range in the service manual is 13.8 to 14.2 as an optimal upper end reading. So its at the low end.

[Steve]

Technically-speaking, 13.8 volts will charge the battery, but it won't charge it fully.

I had a truck years ago that never read over 13 volts when the lights were on (and I had them on all the time).
Not sure why it was low (it went to 14 volts with lights off), but that battery lasted for 7 years.

.

[posplayr]

Technically-speaking, 13.8 volts will charge the battery, but it won't charge it fully.

I had a truck years ago that never read over 13 volts when the lights were on (and I had them on all the time).
Not sure why it was low (it went to 14 volts with lights off), but that battery lasted for 7 years.

.

Steve,
You are correct that 13.8V is enough to charge if not get the battery fully charged, but that is not really driving my answer. If the R/R set point is typically 14.5v then any deviation from that is due to resistance in the connections. I figure the larger the drop the easier it is to increase. So starting out at the cusp is not really where you want to be. The larger the drop the more it is likely to grow so I like to drive it down low(total drops about 0.2V total). Typically with diligence you can get there.
Jim

[Nessism]

Did you rewire the charging system to cut out the stator loop up to the hand control? Add a better ground for your R/R? Check for voltage drop in the R/R power output return to the battery? Doing these things are critical toward having a reliable charging system.

[snackie]

R/R Ground

Nessism,

Before checking the voltage, I had cleaned most of the connections under the seat. Also, I moved the R/R ground (black/white wire) to the battery holder. Is that right? I've attached a photo.

Thanks!

[snackie]

cut out the stator loop up to the hand control

Did you rewire the charging system to cut out the stator loop up to the hand control? Add a better ground for your R/R? Check for voltage drop in the R/R power output return to the battery? Doing these things are critical toward having a reliable charging system.

How do you go about "cutting out the stator loop up to the hand control"?

[Nessism]

How do you go about "cutting out the stator loop up to the hand control"?

Wire the stator directly into the R/R, bypassing the factory harness. You can solder the wires directly or use crimp on terminals. This is critical to the health of your harness because the stator loop often overheats and damages the entire harness.

As for your grounds, get them off that battery tray. That is just the sort of ground that causes problems. Go directly to a solid frame point. Clean the paint off the metal and make sure there is no rust on the attachment.

[snackie]

Wire Stator Directly to R/R

Regarding "Wire Stator Directly to R/R", is there a tutorial for this?
I've not performed a mod like that before and I'm not sure what exactly needs to be done.

BTW-moving ALL grounds off the battery tray now.

Thank you.

[Steve]

Also, I moved the R/R ground (black/white wire) to the battery holder. Is that right?

Although it might look like a good ground, look again. That battery tray is likely rubber-mounted, meaning that it's all insulated.

If you run another wire from that same bolt up to the battery - terminal, it would be OK.

How do you go about "cutting out the stator loop up to the hand control"?

Locate the stator wires where they attach to the harness. If you don't know where they are, look under the back edge of the starter cover, you will see what looks like two wires. Look closer, you will see that one of them is actually a bundle of three wires. Those are your stator wires.

Follow them back, you will see where they connect to the harness. You will find that two of the wires go to the R/R, but the third one disappears into the harness, then re-appears with a different-colored stripe before it connects to the R/R. Disconnect that third wire from the harness and the harness wire from the R/R. Connect the third stator wire directly to the R/R.

.

[snackie]

The stock negative ground has a black/white wire that goes to the same bolt on the battery tray, that's why I moved the R/R ground to that spot. Couple people on the forum didn't think that was a good spot so I move all the black/white grounds to the frame.