Waterproofing / rainproofing the 35a controller on RR+?

[pnwetc]

As someone living in perpetually-rainy Metro Vancouver, I sometimes take my Radrunner Plus out in light rain, and even when it's nice out an unexpected shower can hit now and again. For all its other faults, the stock Rad controller seems to handle the rain like a champ. Now I've come this close to purchasing the Bolton 35a controller, but after searching these forums and /r/RadPowerBikes, I'm concerned by the number of posts detailing how these controllers are much less watertight than the stock controller. I'd hate to drop a couple hundred dollars on a new controller and have it fizzle out under circumstances where the stock one works pretty well.

I've followed with interest handlebar's ongoing experiments with extending fenders, with what seem to be mixed results. But as helpful as those posts are, they make me want to open up the question more broadly: if you've purchased the 35a controller, how do you deal with rainy rides? Has anyone had success with aftermarket controller boxes (especially when mounted on the bottom of a RR)? Has RTV or other kinds of sealant worked out for you? Any other solutions? Or do you simply not bike when it might rain?

[SQFRad]

I'm interested in this too. I'm running the 35A controller, but I don't bike in the rain. I'd like to relocate my controller to underneath the passenger but finding the necessary cables is proving difficult.

[Eric7]

One thing I am thinking of is to use clear bathroom caulking on the outside.  You can always peel it off with your fingers.

This is until you can find a better solution.

[handlebar]

I had to look it up. It's a 35a controller I've had for 15 months. For maybe a year I didn't notice a problem. I see why. Some logic circuitry may be extremely sensitive to moisture, but throttle and PAS would quickly warm the controller enough that the circuitry dried.

About 3 months ago, I finally discovered that the proper tire pressure is 30 PSI. Rolling resistance is so much lower that I've reduced my motor usage by 75%. The controller runs cooler, and if there's moisture, circuitry may take longer to dry each morning. The first couple of miles is when the controller has sometimes failed to recognize a shift.

The bottom and sides are one piece, so there won't be a leak between them. The sides fit into slots in the lid, so that should be okay. The vulnerability must be at the ends. On the front, I saw that water could run through the rubber grommet on the cables. RTV fixed that. I saw that water had sat on top of the controller. I didn't know if the end plate gaskets were totally water proof along the top, but I added a little RTV.

The end gaskets don't fit tightly at the bottom. That was so crazy that I thought they were open for ventilation, and the designer knew that water couldn't flow up into the box. That seems to have been wrong.

With the grommet sealed around the cables and the end plates sealed on all four sides, I think my controller will be okay.

[JTK77]

My custom controllers have sealed seams and grommet. Most importantly The pcb is conformal coated.

[Tony]

You are wise to think about water effect to your 35 amp controller. I?ve had a couple of problems with mine. First problem the front light stopped working, looked inside to see the small lighting circuit board burned.  Second problem I noticed moisture in the display which progresses to slowly destroy the display. This is on a Mini 4.   Third problem to follow later. Water in the controller!

[handlebar]

You are wise to think about water effect to your 35 amp controller. I?ve had a couple of problems with mine. First problem the front light stopped working, looked inside to see the small lighting circuit board burned.  Second problem I noticed moisture in the display which progresses to slowly destroy the display. This is on a Mini 4.   Third problem to follow later. Water in the controller!

Some mornings I've gotten fog in the display of my Bolton upgrade. It's not from rain, so it must be condensation. Parking in the sun will clear it. I don't know if this could lead to corrosion trouble.

[Tony]

Mine started out just looking like condensation which would disappear when parked out it warm weather. It gradually got worse. Probably cheaply made, not sealed well when you consider it has hole in it for a usb connection. I now put a small clear plastic bag over it secured by a rubber band if it looks even remotely like rain or heavy dew.

[Tony]

My 35 amp controller is hidden in a controller box. I went out a few evening ago with the weather forecast showing little chance of rain. I secured my bike outside at my destination putting the bag over the display and seat cover just in case. It rained fairly hard to my surprise.
On the way home at a leisurely ride, the bike started to fly along at full power and showing an erratic speedo. I got the bike under control by natural reaction of squeezing the brakes a little, this cut power to the motor as it should. This happened again further along making it difficult to manoeuvre  when turning at junctions.
  Arriving home I got off the bike and it shot off on its own with my trying to hold on to it. The front wheel climbed up the front of my wife?s car, with the bike almost vertical I managed to quickly pull it over sideways and apply the brake which cut the motor.    It was pretty late, I  don?t think anyone saw this happen but if they did they must have had a laugh at this old fella with the electric bike.  Little damage done just a few scratches to my bike. Next day the bike seems to have dried out and runs normally, I haven?t taken it apart yet to look inside the controller.
Still very pleased with the performance of this controller but it?s powerful  when it?s out of control
.

[pnwetc]

About 3 months ago, I finally discovered that the proper tire pressure is 30 PSI. Rolling resistance is so much lower that I've reduced my motor usage by 75%. The controller runs cooler, and if there's moisture, circuitry may take longer to dry each morning. The first couple of miles is when the controller has sometimes failed to recognize a shift.

The bottom and sides are one piece, so there won't be a leak between them. The sides fit into slots in the lid, so that should be okay. The vulnerability must be at the ends. On the front, I saw that water could run through the rubber grommet on the cables. RTV fixed that. I saw that water had sat on top of the controller. I didn't know if the end plate gaskets were totally water proof along the top, but I added a little RTV.

The end gaskets don't fit tightly at the bottom. That was so crazy that I thought they were open for ventilation, and the designer knew that water couldn't flow up into the box. That seems to have been wrong.

With the grommet sealed around the cables and the end plates sealed on all four sides, I think my controller will be okay.

I appreciate these details, as well as all you've done to record your efforts with fenders etc. I see from your earlier threads that some of your negative experiences came when riding on wet surfaces after a rainfall. Have you been riding in the rain with that controller as well? Apologies if you've addressed this elsewhere and I missed it.

[pnwetc]

My 35 amp controller is hidden in a controller box. I went out a few evening ago with the weather forecast showing little chance of rain. I secured my bike outside at my destination putting the bag over the display and seat cover just in case. It rained fairly hard to my surprise.
On the way home at a leisurely ride, the bike started to fly along at full power and showing an erratic speedo. I got the bike under control by natural reaction of squeezing the brakes a little, this cut power to the motor as it should. This happened again further along making it difficult to manoeuvre  when turning at junctions.
  Arriving home I got off the bike and it shot off on its own with my trying to hold on to it. The front wheel climbed up the front of my wife?s car, with the bike almost vertical I managed to quickly pull it over sideways and apply the brake which cut the motor.    It was pretty late, I  don?t think anyone saw this happen but if they did they must have had a laugh at this old fella with the electric bike.  Little damage done just a few scratches to my bike. Next day the bike seems to have dried out and runs normally, I haven?t taken it apart yet to look inside the controller.
Still very pleased with the performance of this controller but it?s powerful  when it?s out of control.

That's a disconcerting experience, especially since you are using a controller box as well. I'm not sure an aftermarket box would really fit at the controller mounting point for RR+'s anyway, but this doesn't make it sound like they (or at least the one you're using) provide much protection.

[handlebar]

I appreciate these details, as well as all you've done to record your efforts with fenders etc. I see from your earlier threads that some of your negative experiences came when riding on wet surfaces after a rainfall. Have you been riding in the rain with that controller as well? Apologies if you've addressed this elsewhere and I missed it.

I'd need goggles in the rain. I haven't used goggles except for bugs, so I guess I haven't ridden in rain. Raining or not, I guess most of the trouble for the controller would be from water the tire picks up. My fender extension is doing well against that. Sometimes it sounds as if I hit a little piece of thin plywood. That seems to be from picking up a stick that jams against the extension. It's loud but hasn't done any harm.

[JedidiahStolzfus]

I got to thinking about this thread while on a ride on wet roads.  It wasn't raining, but it had and the roads were wet, but I didn't go through any puddles.  But my concern is that I have the 35A controller on my RR2 and it's mounted where the factory controller was.  It's low to the ground and there's really no way to cover it to keep the spray out. 

But then I remembered one of my first jobs working for a defense contractor building weapon subsystems.  Any PCB that had the potential to be exposed to wet conditions was conformal coated.  It's a spray that coats the board and basically makes it waterproof.

Fortunately the product is available on Amazon: https://amzn.to/3DKpKJC

I'm thinking about tearing my 35A controller apart and giving it a spray.  There is a drawback to this stuff though and that's if the board gets too hot due to a failure.  It will catch fire.  During my days of testing components that were installed in torpedoes I saw multiple boards catch fire during the tests.  The fire would go out as soon as power was removed, but the fire destroyed the pcb.  Which was a problem because we only had so many spares at the time.  I guess in the case of one of these controllers a new one could be ordered.  If it shorted out and caused a fire, it would have needed to be replaced anyway.

The other solution would be to figure out a way to seal up the enclosure the PCB is inside.  Maybe use a thin bead of RTV around the seams.  Or maybe spray the entire enclosure with the conformal coating linked above. 

[handlebar]

The other solution would be to figure out a way to seal up the enclosure the PCB is inside.  Maybe use a thin bead of RTV around the seams.  Or maybe spray the entire enclosure with the conformal coating linked above.

I have the Bolton upgrade controller on a Radrunner. The first time I used RTV, I left the bottoms of the end pieces unsealed to allow ventilation. It seems a problem may come from mist, which can be drawn up with air. I haven't had trouble since I sealed the bottoms.

[JedidiahStolzfus]

The other solution would be to figure out a way to seal up the enclosure the PCB is inside.  Maybe use a thin bead of RTV around the seams.  Or maybe spray the entire enclosure with the conformal coating linked above.

I have the Bolton upgrade controller on a Radrunner. The first time I used RTV, I left the bottoms of the end pieces unsealed to allow ventilation. It seems a problem may come from mist, which can be drawn up with air. I haven't had trouble since I sealed the bottoms.

Is there space inside to slip in a small desiccant pack?  Spraying the PCB with conformal coating would also solve that problem.