Riding in the rain shorted out my ebike

[praskal]

I have a rear wheel XLyte hub BLDC Motor. I use a 72V 20amp controller. I have two 36V SLA in series (so 72V total).

Horrible problem a couple days ago. I was riding to work in the rain. Suddenly the power kicked on wide open, eventhough I was not pressing the throttle. I had to brake forcefully just to slow down at traffic signals. When I got to work I had to very forcefully apply the brakes enough to stop the bike. I hopped off and bent down to disconnect the leads from the batteries to the controller when all of a sudden the motor completely stopped. Ever since then I can't get any power at all to the motor.

I don't know if something like the mosfets blew in the controller or if something malfunctioned in the motor itself. But when I push the bike I am noticing that the hub motor has some friction and kind of "chunks" along. I have no idea what to do? Any help would be appreciated very much.

Patrick

 

[deardancer3]

Due to the design and complexity of the controllers, Brushless controller failures have less liklihood of applying full power to the motor on their own. A brushed motor controller, with just one FET shorted, ( or moisture induced short) can apply quite a bit of power to a brushed motor.

Since you have a brushless motor and got a lot of motor power applied in the rain, The probability is that initially you had a throttle failure (or a controller throttle circuit problem) caused by the rain, since there have been several reports of this happening on crystalyte systems, and, has even happened to me.

(You did not say whether or not you had switches on your ebrakes, but since you did not state this, I will presume you did not have this feature. Correct me if this is wrong.)

No ebrake switches, so when you applied brakes, you caused the current to drasticaly increase when you were stopping/slowing. (In many situations, the ebrake switches might have suspend motor power)

If you are real lucky, you have a blown fuse somewhere. Or a connection gave up or maybe a wire.
Or blown FET's or worse if you are not lucky. this in addition to a moisture induced throttle circut problem.

The very good news is that you are safe and un-injured. Some folks get into accidents and get quite hurt when this happens.

Disconnect the battery from everything and see if you get the appropriate voltage at the pack out put.

inspect all connectors, fuses, and connectors.

put the bike on a stand to keep the rear wheel off the ground, and reconnect the system. remove the cover from the throttle and get it dried out.

Motors seldom blow windings, and are fairly easy to ohm out to verify continuity.

Other posters may help with more detailed trouble shooting if your battery is ok.

Write youself a note that, After you get out of this jam, to install one ebrake switch and a motor kill switch. you have used up a fair portion of your good luck.

dick

 

[praskal]

I do not have ebrakes. I also do not have a fuse.

I unplugged the controller from the motor and the resistance went away. Yay! So this means that something is shorted out in the controller. Of course, the main thing that will get shorted out is the mosfets. Too bad.

The batteries are fully charged and are putting out 76V on my voltmeter. I did not know that should have fuses in the system. Now it makes perfect sense. Would you put a fuse on the black (positive) lead or the red? Or both?

Okay, I opened up the controller and it is FRIED. I guess I need a new one. I think I should get a 35amp 72V controller this time with a fuse in line. The two 20amp controller I have had have both blown. Also, they get hot easy and cut out power right in the middle of my commute frequently.

 

[Drunkskunk]

Best to put the fuse on the red wire. If you put it on the black, and it blows, you might leak electrons from the wire, and that kind of thing can ruin your bike's paint, not to mention the mess on the garage floor.

 

[EMF]

Drunkskunk is kidding a little bit, but he's giving good advice about where you want to locate that fuse. I put the fuse on the positive side, because like a switch, you always want to cut power on the "hot" side.

If you had your fuse on the negative or ground side, you might not get any protection, if the short was ahead of the fuse. Such as in a rainstorm. Or as in your case, the throttle appears full on to the controller. Then, no matter what, if your battery pack, starts flowing too much current, the fuse will step in and save your equipment, as it is sitting between the power source and your motor/controller. So, when you hit your brake and threw a big load on your system and the amps went crazy, the fuse would have (hopefully) blown. Having said that, put the fuse close to the battery pack.

 

[Deepkimchi]

If you are going to run 72V might want to get the modified 50A 72V controller at ebike.ca.

There is a sticky on how to upgrade FETs if that is the only thing that is fried. maybe you can used the fried version as your experimental 2nd alternate controller.

 

[praskal]

That 50amp controller is $310 without shipping. Damn. 50amps would drain my batteries in a couple minutes probably.

About the fuse, if I had a 40amp controller, would I use a 50amp 100V fuse? Or what?

 

[mvadventure]

I started a thread last summer about my 5304 trying to kill me as it too wouldn't shut off or slow down. The rain I got caught in was my first and worst so far and it was definitely scary even though I was in a rural area there was still traffic. The power went off however when I turned to key off so my problem wasn't in the controller but either in the cruise or throttle and I tend to think it was the cruise brake on the throttle side as that hasn't worked since. I do not pretend to understand how that would do the nasty but the nasty was done and that is the only thing that doesn't work.

Suggestions were to use silicon to seal all exposed areas and that I have done. Now, if possible, when it STARTS to rain i put plastic bags over the throttle and cruise control before I put my rain suit on. Thus far it hasn't happened again but I haven't been caught in a real drencher. Yet. I keep my controller as waterproof as possible all the time, so far it hasn't gotten too hot despite the rather warm days we had this summer. It's mostly perfect bike riding weather right now though and heat isn't a situation. Sixteen miles this morning in 45 minutes including a stop at the hardware store. 20 miles yesterday in an hour and fifteen minutes of very pleasant sidewalk riding along the ocean.

Mike

 

[calinb]

Patrick,

What kind of throttle do you have? Twist grip? Thumb levers? LED annunciators? I've ridden in some very heavy rain with my 1/4 twist grip and had no mishaps so far. Maybe just lucky.

Thanks,

-Cal

 

[praskal]

Well, I have a thumb throttle. But there is a portion of the lead that goes to the controller that was not waterproofed. It was pouring. I could see that it could short out. But now that I have a new controller and everything, luckily the throttle still works normally. So it needed to be dried out only. I got a cycleanalyst this time, so I can can tabs on the ah's. That's nice to be able to do.

 

[kbarrett]

I think I'm going to put a small tube of dielectric silicone grease in my bike's tool bag ... just so it is handy to glom into the throttle if I am about to get drenched.

 

[NickF23]

Living in the UK its happened to me all the time when I used to ride in heavy rain. Normally the drainbrain would stop function first, then the batteries would short a little but stil kinda work ok, then the throttle would start going ballistic. Everything would recover when the bike dried out. Standard crystalyte throttle quite easy to short. I think you can buy a waterproof throttle somewhere (magura perhaps? not 100% sure it works with a crystalyte controller maybe extra resistors?) combined with good waterproofing of the connector and controller rain shouldn't be a problem. Forcing the motor stop with the throttle on full is the simplist way to blow a controller. Hence a kill switch of some kind is pretty important.

 

[calinb]

I think I'm going to put a small tube of dielectric silicone grease in my bike's tool bag ... just so it is handy to glom into the throttle if I am about to get drenched.

During last week's heavy rains, I noticed my twist throttle was occasionally sticking on slightly. I also noticed that the large diameter disc end of the throttle grip--the end that seals the twist grip against the housing--had a bit more of a gap than usual. I loosened the set screw on the housing and pushed it up solidly against the white disc, closing the gap with the grip. I also glued the stationary half of the grip securely to the bars so it can't loosen up on that end. I've had no problems since then, but this gap is obviously a point of water entry into the housing.