Controller Heat and Fuse change

[erdurbin]

What would be a safe temperature for the controller? I rode mine yesterday for about 15 minutes and when I got back to the house, it was very hot to the touch. I had it in a Craftsman tool bag on top of the batteries. It was zipped up to conceal everything and I do not think it was getting enough air. If it will get hot no matter what, I will just leave it in the bag, but if not, I want to get it out in the open so it can have airflow.

On another note, I too blew my fuse that came with the kit on my first ride attempt. I bought an inline blade fuse holder from Radio Shack and got a package of 30 amp fuses. The wire is 10 awg and more durable than the wire on the original power leads. I work in IT and know the guys at my local Batteries Plus. They gave me some extra battery connectors that UPS's use. I connected all 3 of my 12ah batteries no problem with these, no solder. This is a great idea for anyone that doesn't want to solder. I placed them in a nylon craftsman tool bag from Sears and they fit perfect. It has a zipper top and handles so I can take the whole bag into work for charging. I will try and get some pictures posted soon.

[myelectricbike]

Air circulation is very important for the hub if you do a 48 volt mod but like the hub power phase leads decreasing the wire gage means the windings are less protected (not a good thing). In your case the wiring to the controller circuit board from the rig you setup is less protected by the lower gage wiring so if the fuse does not blow then the higher gage wires will be the ones that loose their insulation first. Since Anderson Power Pole connectors run over $35 each if that is what they gave you then you got a bargain indeed. (Be sure there is nothing wrong with them before it may be too late.)

[erdurbin]

I just have the 36v standard. For the power connectors, I already had 2 from a UPS that went south on us here at work. I got the other from Batteries Plus and cut the 60 amp fuse off. Then, I had the leads ready to butt splice onto the power connector. I had no idea they were $35 a piece. My entire power setup is with 10 gauge wire and a 30 amp fuse. There are 60 amp fuses between each battery, but I don't think they would ever blow.

I guess that really doesn't answer my question. I was wanting someone to give me an actual temperature reading of the outside of their controller after a 10-20 minute ride. I am not worried about the wire melting as I believe the gauge is plenty and the fuse should protect me. I was just not sure how hot the controller would be.

[myelectricbike]

Someone recently posted they had measured 30 amps going to the controller and there is a built in output limit around 20-22 amps so that mean the controller is doing something with 8 to 10 amps besides sending it to the motor. My question is hoe much of this is being turned into heat but I've never had any problem with high controller temperatures since my controllers are normally mounted exposed under or on top of the handle bars. Inside a bag where there is no air circulation my guess is that temperatures could get high enough to turn your ebike into a hot air balloon. Try testing the temperature on your own controller both in the open and in an enclosure and let us know if there is any difference.

[erdurbin]

I went on 30 minute ride tonight full throttle about 80% of the time. I mounted my controler to the side of the frame this time. No heat on the controller to the touch. The batteries were about 95 degree F. I thought that was fine in a sealed bag. In a UPS, they are in a sealed environment as well, (some smaller ones do not have cooling fans). They should be fine in this setup. The controller in a bag is a bad idea. It felt very warm to the touch, not enough to burn, but definitely not something you would want to continue. Leave your controller in open air and let the wind help.

I also hear that if you give anything less than full throttle, you will heat up the controller significantly because it must regulate the voltage going into the motor. The wasted voltage is converted into heat. I haven't tried this and probably never will because I always run it wide open or off (except when I first take off it is gradual with the pedal).

Either way, I am very happy with my kit. I hope it holds up for quite a while.

[myelectricbike]

I'm not suggesting you try this but a few months ago I saw a computer that had all the fans removed but instead of being water cooled it was completely submerged in vegetable oil. I would never be able to do that with my computer because I'm always changing stuff around but a controller might be different. That way you might be able to get away with having it enclosed in a bag or bucket or some other container so it could be used in bad weather. These controllers are not water proof even though they have silicone around the wiring. Then at least if it does heat up in the oil you can carry along a bag of potatoes! 

[erdurbin]

I saw that too, let me know when you try it.

[29a]

Since Anderson Power Pole connectors run over $35 each if that is what they gave you then you got a bargain indeed.

The first time I saw this in another thread I thought it was a simple typo ! (or maybe you where quoted price per case of connectors)
Anderson Powerpole connectors here in Canada $0.95 each (canadian) available at most RC hobby stores rated 15-80 amps (allso available from most forklift truck repair shops).

[timevex]

I've been running my controller (36v 500w front motor) in a plastic bag mounted upside down under my battery rack that is located in the center triangle. After running the bike for over an hour on 100% motor (no pedaling) up and down hills mostly full throttle the controller has gotten only slightly warm, certainly not hot at all. And that's all wrapped up in a sealed plastic bag to keep it clean and dry (obviously not recommended for keeping it cool).

Perhaps you have some mosfets blown that’s forcing more current through the working mosfets (just a guess)

Tim