F800GS R/R Mosfet replacement....How to...

[ebrabaek]

So after reading the awesome thread posted by Joel regarding the Batteries, and the stator issues with the bike... I decided to jump on as a beta tester. I have already had one dead battery, but as many explained there were issues with them. I want to raise the charging voltage to 14.2 volt+, and I think by now we have all come to the conclusion that with the exception of a few..... the 8GS is charging too low. So using the link that Joel suplied.... I purchased a Mosfet R/R from a vendor in Joplin,ME. We can get all technical regarding the benefit...etc... But in short By raising the charging voltage to 14.2+.....your charging system would greatly benefit......specially setting you up for a LI battery. So a few measurements was necessary before the surgery. I recognize that the temperature of the case outside the stator is iffy at best, since latent heat from the headers...airflow....etc... will render it mostly .....ummmm. just for fun. But I set it up anyway. After a cold engine start.... and a 8 mile ride 6 of which was on the freeway at 60 mph.... I let the bike idle, and took the following measurements. I got the R/R from this ebay vendor... Thanks to Joel for the link....


Idle after a 5 minute cool down.....


3000 rpm after same 5 minute cool down......


Idle after 10 minutes.......


Then the fan cycled 4 times....and the voltage dropped to 13.45 volts with the fan on.....


After 15 minutes the temp seemed to stabilize at 263.5 deg.F.... The rise was slowed down a lot.....


Here is the kit purchased..... No markings.... But very good instructions..... That was written in English...in this country... Which is awesome to see. It was ordered and shipped within one day.. Very good service...


With those baseline measurements in hand.... I will now cut the stock R/R off,and begin the surgery..... Be back shortly with more pics....



Erling

[GB]

if this is successful, I see a small market for a plug and play conversion kit

[Indy Unlimited]

I got my MOSFET R/R sitting on the bench with a new stator. Will get to it soon as well. Thanks for the beta testing.

[ebrabaek]

IT LIVES............. Ok first thing first....
Removal of the stock R/R....


Remove the seat.....


Start removing the top panel.....




Side panel removal.....


Fairing screw removal.....


Side plastic screw removal.....


Beak...... two screws removal....


side plastic screw next to radiator.....


Bottom side panel screw removal....


Bike will now look like this.....


Disconnect the positive battery terminal.....


To be continued....

[ebrabaek]

The two R/R's next to each other.... Stock on the right.....


Follow the three yellow wires backwards from the R/R..... and cut them a couple of inches from the plug.....


Solder the three new terminals in..... There are 3 inputs to the new R/R from the stator. It does NOT matter which goes where....


Then trace the DC side back to the plug. Here is where I started scratching my head..... There were two sets of DC wires coming of the R/R. two red with white stripe, and two greens. I do not have an electrical diagram so after ohming and voltage tracing... I concluded that they are run in parallel. Seems odd.... and I am suspicious of that one routes to the ZFE....or another brain box... so when I tie them together.... I now have a constant drain on the battery that otherwhy would only drain when the stator is produccing power.... I will return to this shortly....
Follow the DC wires to the plug..... Cut them and splice them together......


Solder in the positive cable with the 30 amp fuse....


And the negative.....


It now will look like this....


Drum roll please...................................:c lap....

[ebrabaek]

It Lives....... and nicely so ....if I must say......
Idle charging went up.....


3000 rpm.......


AC ripple is about the same.... but controlled better. Recall the stock were about the same.... But then peaked at about 120 milli volt AC..... Regardless of throttle position the AC ripple was steady at 72 Milli volt AC......


I am curently working on the mount. It will mount to the stock holes.... but is to tight for my taste... But more importantly... I wanted to move it to where the Charcoal Cannister once sat..... I am also observing the rate of discharge to make sure some box is not still on since I spliced the two wires.... Perhaps someone with a diagram can chime in.... Or if we can knock Joel of the bike....... He could shine some light on this.....

Erling

[ebrabaek]

I have observed the drain switching the key off a dozen times.... and it seems to indicate a 60 milli amp draw, that then drops to 10ma...after about 20 seconds....and after 30 seconds....it drops to zero....indicating all is switching off as it should. I am making a bracket to house the new R/R......and after much thinking I will leave it in the same location...just tilted a bit.... for my taste. It is really up to the individual taste.... but I'm kind of handy with the composites stuff....and can whip a bracket up about as fast as you can saw and bend a sheet of aluminum.... Stay tuned....

Erling

[dsrydr]

What large cojones you have. Very encouraging. Thanks for posting!

[ebrabaek]

Originally Posted by dsrydr

What large cojones you have. Very encouraging. Thanks for posting!

..... I must say that I felt about the same intimidation....as right before I head into a level 2-3 thunderstorm....all armored up......

Erling

[ebrabaek]

So I have observed the battery drain..... and over a two hr span....it went from 13.12 volts to 13.045 volts.....and that looks like a normal idle drain as the cells settles down. The fact that the charging voltage was upped by about 0.5 volts with less AC ripple is very encouraging

[ebrabaek]

Here is a video of the first start...... I was little nervous...... Note how the voltage is climbing and then stabilizing regardless of rpm......

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Erling

[grndzr0]

Awesome!!!! Thanks a bunch man!!!

Ryan

[JRWooden]

Originally Posted by ebrabaek

I have observed the drain switching the key off a dozen times.... and it seems to indicate a 60 milli amp draw, that then drops to 10ma...after about 20 seconds....and after 30 seconds....it drops to zero....indicating all is switching off as it should. I am making a bracket to house the new R/R......and after much thinking I will leave it in the same location...just tilted a bit.... for my taste. It is really up to the individual taste.... but I'm kind of handy with the composites stuff....and can whip a bracket up about as fast as you can saw and bend a sheet of aluminum.... Stay tuned....

Erling

Erling:

1) Per the wiring schematic in the Haynes manual the four wires (two hot and two ground) do indeed go JUST (directly) to the battery and do not wander off to the ZFE or other places. I speculate the same as you ... the needed more current carrying capacity and didn't want to use a single heavier gauge wire as it would make it harder to route the harness.

2) I'm sure the stock regulator got very hot... I've never put my hand on it...
I'm sure that the MOSFET regulator still gets hot ... maybe not AS hot...
So I'm thinking that with the metal bracket bolted to the frame that it does act to extend the heatsink function somewhat .... not sure how big the effect is, but maybe you don't want to use a composite bracket?

Just because I could, when I took my R/R off to get the P/N off the back I re-assembled it with heatsink grease between the R/R and the bracket and also the bracket to the frame.... I know I know ... don't go all on me ... it only took a minute.

[grndzr0]

Originally Posted by JRWooden

Just because I could, when I took my R/R off to get the P/N off the back I re-assembled it with heatsink grease between the R/R and the bracket and also the bracket to the frame.... I know I know ... don't go all on me ... it only took a minute.

LOL, Nice!!!

Ryan

[ebrabaek]

Originally Posted by JRWooden

Erling:

1) Per the wiring schematic in the Haynes manual the four wires (two hot and two ground) do indeed go JUST (directly) to the battery and do not wander off to the ZFE or other places. I speculate the same as you ... the needed more current carrying capacity and didn't want to use a single heavier gauge wire as it would make it harder to route the harness.
Yay.... Mystery solved...... Thank you sir.


2) I'm sure the stock regulator got very hot... I've never put my hand on it...
I'm sure that the MOSFET regulator still gets hot ... maybe not AS hot...
So I'm thinking that with the metal bracket bolted to the frame that it does act to extend the heatsink function somewhat .... not sure how big the effect is, but maybe you don't want to use a composite bracket?
You are right that the composite is like an insulator, but mind you the stock bracket is not touching the stock R/R , because of the little nut inserts... It's like 1/2 mm gap.... Plus there is a big hole cut out in the center.. Mine will mimic that.

Just because I could, when I took my R/R off to get the P/N off the back I re-assembled it with heatsink grease between the R/R and the bracket and also the bracket to the frame.... I know I know ... don't go all on me ... it only took a minute.

I personally believe that most if not all the heat is dissipated through the front heat sink. For the little time I ran it...it did not get very hot. I did not do any heat testing on the R/R, but have been assured that this unit will hold up to the heat quite fine. This unit is fused at 30 amps. Max draw of the stator is about 28 amps at full screw. I believe this units origin is Japan.

Erling