Blew controller by hooking battery up backwards

[fechter]

So I figure something is pretty dead in the controller. Unless anyone has any great ideas I'm going to leave this one for organ donation to some future controller.

Hmm... I might be interested in an organ donor like that. It may be beyond repair too.

 

[spinningmagnets]

Concerning electrics, I'm a toddling infant, and this is so annoying to me (I'm still learning)...I get that the mass market is very sensitive to minor differences in price, but...

I understand adding diodes and FET's make a controller more expensive, (even if its just $5) but it costs the same to make two black wires as it does to make a black and red wire. Changing the positive cable to red is one of the first things I do to old cars that I've bought. Also putting red felt ring around positive battery post.

I don't know what a FET does, but I keep reading about controllers having the FET's upgraded, they should be mounted in a socket, like computer RAM memory cards. (I am also a computer infant, but I have followed instructions and swapped out RAM cards)

Fechter, when will you start selling your "Fech-troller 3000" kits?

 

[dnmun]

they already have a red and black wire. he swapped out connectors as i remember. that was how the mistake happened originally.

the FETs need a lotta solder for the connection because they carry so much current.

i would like for richard to get the bones so he can open it up and we can see how it failed when it was reversed, educational. he may be able to fix it for fitek too, and they are close already, just driving a little. jmho. sorry richard, more work in 2 days.

 

[fitek]

I think I had the controller on the table at the Maker Faire when Fechter came by... or maybe I hadn't pulled it out of the box yet...

I'll find a use for the FETs if nothing else. I got a cheapo solar charge controller from Frys last night... only 10amps charging current? needs an upgrade!

 

[fechter]

I think I had the controller on the table at the Maker Faire when Fechter came by... or maybe I hadn't pulled it out of the box yet...

I'll find a use for the FETs if nothing else. I got a cheapo solar charge controller from Frys last night... only 10amps charging current? needs an upgrade!

It was still in the box. I am interested in playing with it if you give up. Don't bother removing the FETs. I have piles of them, I can save you the work.

 

[The Stig]

I just accidentally hooked up my infineon backwards and it survived no problem... phew!

 

[fitek]

So I said earlier that the hub motor blew up. It seemed unlikely, so I took the motor apart. It looks fine.

I tested the controller with another motor-- and nothing. Tried swapping throttles, no go.

Looks like another dead controller? What gives, I didn't even do anything to it-- used it for maybe 15-30 minutes max. There's no "debug" LED like the v1 ecrazyman, so how do you go about debugging this thing?

 

[fechter]

Measure the voltage at the throttle connection. See if you have 5v there. You can also check for voltage at the hall sensors. With everything disconnected, you can try measuring resistance between each phase wire and either battery wire. None of the 6 combinations should look like zero ohms. If so, a FET is shorted.

I'm still interested in the little sensorless one if you give up on it.

 

[fitek]

Thanks Fechter.

Let me see if this controller is dead too. If so, I can mail you both (I generally only make it up to SF on the weekends, I don't assume you work then?)

 

[fitek]

Fechter, checked voltages, all good, checked FET resistance - the low side FET on phase B blew out, all pins shorted. I replaced it with one from the dead controller, but I did a really shitty soldering job. Does sort of spin the motor now... Will have someone with better skills and tools check it out tomorrow evening.

 

[fitek]

Success, the controller now works again. Man, how crappy that it blew out with totally normal usage. My old Ecrazyman has been totally solid.

Replaced IRF1405 into the "dead" controller and tried it too, but it just heats the big resistor on the corner of the board up. Something is drawing a lot of current, I'm guessing the resistor is for the logic side.

Fixed my scope last night, so I'll poke around a bit.

 

[dnmun]

that's normal. the power resistor has to dissipate a lot of heat and gets too hot to touch after a few minutes.

do you have a voltmeter? if you can test the12V and 5v rails and verify that there is signal from the hall sensors and the throttle, you will know a lot then.

do you know if it was the high side or low side driver you replaced?

 

[fitek]

The controller that just stopped working-- it was the low side on phase B that blew out. I took one of the FETs from the controller I hooked up backwards to make it live again.

Will measure the voltages and report back.

Now that I have a working and a non working controller, it should be a lot easier to troubleshoot...

I got a handful of IRF1405 now too, maybe they'd be an improvement over the stock FETs (which I could use in my experiments that often end up with dead FETs).

 

[fitek]

I hooked the controller up and I'm getting some action out of it, but the IRF1405 blew out. Grr. I'll have to find another sacrificial FET.

So perhaps it is possible to easily recover (LM7805 and some caps).

 

[mpmackd]

I bought a 48v 1000w YXM motor kit off eBay recently. The battery BMS has a red and black wire coming out of it, but the connection adapter it came with has a brown and blue wire that's supposed to connect to it. Then that adapter connects to another adapter that connects to the controller.

So ya, it's not always so simple as red-to-red and black-to-black. It took a while before I found out how to hook it up. I finally found out through a dozen emails and forums that it's red-to-brown.

If anyone else bought that kit off eBay with the 20AH battery, send me a message.