BBS02 750W controller dead

Hi,
This morning i was about to head out on my bike, fitted with a 48v 750w bbs02. i had it set on to number 9, and was in 7th gear. I pressed the thumb throttle, the bike jumped forwards and i quickly pressed the break lever to cut off the motor.

Now i can not get the bike to work. i have tried turning it off and on, leaving the battery disconnected, everything. All i get is a small click from inside the motor when i press the thumb throttle. there are no errors coming up on the screen. and the battery was fully charged.

The motor does not respond to pedalling, just makes a single click when pressing the thumb.

I opened up the motor, and when i disconnect the 3 motor phase wires, i can turn the motor easily (by turning the sprocket in reverse) and when i connect 2 or more of the phase wires back, the motor is very hard to turn.

Does this suggest that the controller is broken somehow?

Any help from anyone would really be appreciated.

Did you disconnect the brake to make sure that it is not a failed brake switch?

Hi, Thanks for your reply.
one of the first things i tried was disconnecting the brake cutoff cable thinking it may have become stuck on. then disconnected every connection and reconnected everything. the clicking noise stops when i press the brake lever and press the throttle so it sounds like that is ok.

I opened up the motor and connected my multimeter between the battery ground, and each of the 3 motor phase wires and it shows battery voltage of 48v on each phase wire.

when turning the chain backwards it is very hard to turn, but if i desconnect the 3 phase wires, it turns easily and i can hear the motor turning.

I want to eventually use a CAv3 with the motor so might be able to get a 3rd party controller and connect to the motor.

Sounds like blown FET/S in the controller.

Several failures with the same symptoms here. What is the common denominator?

How whey happened to be used?
How they were programmed?
Battery voltage?
Production lot?
Something else?

I've plugged into the computer using the programming software, and found that it was programmed with "initial current %" on the software showed 100%. From what I've read on the forum here it can create excessive current. Assuming this is what has happened and the fets are fried, I have ordered a pack of 10 of the same fets as in the controller from china for $4.83 (£2.93) and will try soldering them in as I have nothing to lose. If that doesn't work I might need some advise on a normal controler to replace the broken one. But I want to use a cycle analyst. So I would get a controller with a cycle analyst interface plug.

Anyone good with electronics that would know if it is likely just to be the fets or whether any other components are likely to need replacing?
Thanks in advance.

ac246 said:

I've plugged into the computer using the programming software, and found that it was programmed with "initial current %" on the software showed 100%. From what I've read on the forum here it can create excessive current...

Click to expand...

I'm not familiar with this thing, but it sure sounds like you are on to something...

i think it is the amount of current that when the throttle is first pressed, so having it set to 100% turns the throttle into an on off switch which is why mine fried.

I have done some tests on the controller board, There is a short between the Blue phase wire and the Battery Positive. I will try soldering in new FETs and see if this helps. maybe the controller is sensing the sudden surge of current from the short circuit which is why it only gives a click then cuts out straight away.

Red > Green 14k
Red > Yellow 14k
Red > Blue short

Black > Green 10k
Black > Yellow 10k
Black > Blue open

Succesfully repaired my blown controller. It was just clicking when pressing the throttle, or when turning the pedals, or when pressing and holding the walk assist. I removed the controller and removed all of the rubber around it. Then identified the faulty FETs and ordered the exact same ones. P75NF75 and soldered these in their place and now it works brilliantly. Have reprogrammed it from the computer so now it starts gently and also limited the controller to 18A.

I spoke with a friend who is an electronics engineer and he said that one of the FETs will be shorted and causing the overload circuit to turn off the power. Which is why there was an initial click.

Once I took them out I noticed it was only one of the fets on the blue phase that was blown but without taking them out I would not have been able to tell. So I replaced all three. Cost me about £3 to order them on ebay but they would have taken 30 days from china so I also ordered some off of rapid electronics here in England for £15 with next day postage for 9 of them.

Hopefully this will help someone else repair their burnt out controller.

That is great news for bbs02 owners

ac246, I am intrigued on how you managed to remove the potting compound from the controller. Do you have any photos you can share?
This has always looked like a daunting job with simply digging the compound out not really an option due to the potting mix molding around all the components.

I am really please you managed to repair the controller and is indeed great news for BBS02 owners.

You will need to also consider how you are going to re seal the controller. The drive is designed to use a potted controller as the cavity where the controller resides in is designed to breath and has vent holes machined into it.

Great job and fantastic news for many of us. I too have the same problem but my bad kit was a freebie and I was just waiting for someone with more electronic knowledge to figure it out. Now I'll look into repairing my bad controller. Thanks for the fix.


Bob

Hi, i went for a quick 9 mile spin round the local woods and it works perfect. i have some photos of the controller. The potting compound was really easy to take off, it is just like pealing silicone sealant off of something. it is very rubbery and came off very easy. i actually used a small flat headed screwdriver. i tried uploading some photos but it said they were too large. i will try to make them smaller and try posting again. I will look into a way of re potting the controller.

Some photos of my controller. I didn't take many photos.

There are a few un used holes on the controller which look like they were for potential header plugs which werent used such as on the second photo.

Really appreciate this ac246. I've now had 2 controllers blow on me, both within the first 10 miles. The replacement one from EM3EV just blew a hour ago after 4 miles. I also think that my throttle is faulty - this seems to be a common issue.

The bike was running fine in PAS mode so I didn't both to connect the throttle initially - as this seemed to be a problem when the last controller blew. I cleaned the throttle with some electrical contact cleaner and plugged it in. The bike slightly lurged forward without be touching the throttle and then the motor stopped responding all together. So annoying. Luckily I wasn't too far from home so smashed a few Flat Whites and trundled home manually... lame.

Are these the badboys you ordered http://www.rapidonline.com/electronic-components/p75nf75-mosfet-t0220-80a-75v-47-5622 I'm going to give this a go myself and report back. Anything else needed for the repair? E.G Conductive epoxy?

Did you refill the controlled with Silicone?

gorndog said:

Really appreciate this ac246. I've now had 2 controllers blow on me, both within the first 10 miles. The replacement one from EM3EV just blew a hour ago after 4 miles. I also think that my throttle is faulty - this seems to be a common issue.

The bike was running fine in PAS mode so I didn't both to connect the throttle initially - as this seemed to be a problem when the last controller blew. I cleaned the throttle with some electrical contact cleaner and plugged it in. The bike slightly lurged forward without be touching the throttle and then the motor stopped responding all together. So annoying. Luckily I wasn't too far from home so smashed a few Flat Whites and trundled home manually... lame.

Are these the badboys you ordered http://www.rapidonline.com/electronic-components/p75nf75-mosfet-t0220-80a-75v-47-5622 I'm going to give this a go myself and report back. Anything else needed for the repair? E.G Conductive epoxy?

Did you refill the controlled with Silicone?

Click to expand...

But as ac246 mentioned he reprogrammed the controller as well. Could be the fracture is miss-programing a lot of these controllers. Of course that would be strange that even new one sent to you are also miss-programmed. But who knows. You might want to check this out.

Bob

Yea I will order some UP, and reprogram. Paul at EM3EV was kind enough to throw in a LCD extender cable when we sent the replacement controller. I have the USB serial hardware and just need to slice this cable up, wire it to the USB serial and then I can programme the controller.

Hi Gorndog, Yep, they are the right Fets. P75NF75 manufactured by ST microcontrollers.

The throttle can put a lot more power through the FETS than the pedal assist the way it is pre programmed.

I noticed a potential design problem on the controller board, which could be causing excess heat and blowing the FETs but wouldnt happen very quickly like we have experienced... They have tinned the power tracks on the pcb to make them thicker by using solder, and on the track around the edge they have used a piece of wire to thicken up the track, but this does not go all the way to the end so could be causing excess heat which is conducted into the FET. Some parts of the tinned tracks are also a little thinner where there is less solder. Just a theory though.

Theres possibly a way to solder a programming port directly onto the controller instead of having to make a programming cable. for mine i just sliced the cable that lead to the screen, and connected 3 wires from the ground, RX and TX wires to one of the USB to serial convertors.

When i want to program the motor i just turn it on as usual and connect the usb to the three wires and then plug it into the computer. The LCD displays Error 30 while it is plugged in but it allows very fast testing as all you need to do is pull one of the wires off and then test the bike.

The potting compound in the motor will need to be replaced but i havent yet. i wanted to test the bike out fully first. and i need to find a potting compound that is just as easy to remove as the original.


This week i may be able to take my motor apart again and take some good quality photos of the PCB showing the port for where we could solder a programming port directly. No point doing this though unless you are removing the potting compound to repair. I tested mine out after reprogramming, then changed the settings down to 18A.

My other project im about to start is to replace the controller completely with one of the controllers off of em3ev, (9 fet IRFB3077 Infineon Controller (Motor With Hall Sensors) ) and then use this with a cycle analyst. I have started another thread to write about this. I have Just placed an order for them so hopefully by the end of the month it will be up and running.

Nothing else special needed for it, Maybe put some more conductive paste behind the Fets but there is a conductive pad behind them anyway so probably dont need them. Dont forget to put the screws back in before re soldering them in. and use a multi meter to just double check there is no solder bridging between the legs on the fets as it may damage something else on the controller. check the multimeter readings on one of the other fet triplets and make sure that the new readings are pretty much similar afterwards.

Good luck...

Again thanks posting this. It will certainly help lots of people and also give others holding back a bit more confidence to go with the drive now we know we can DYI repair it.

Also gives the opportunity to change out FETS to higher quality units if you want to.

Kepler said:

It will certainly help lots of people and also give others holding back a bit more confidence to go with the drive

Click to expand...

I'm sure they'll be thrilled they had the confidence to go with this drive when the controller dies in 20 or so kilometers. Even so that it has been proven possible to fix it yourself, I'm sure that people are buying these kits to ride, not to fix(repeatedly?).

Paul from em3ev.com is sending a new controller. He said it's a known problem and that he's had a few of these dead controller warranty claims. Not much good telling me this now. If he'd told me that when I was buying the drive then I'd still have bought a battery from him, but I'd be happily out riding right now with an AFT kit, my other choice. You get what you pay for, and now I am serving penance for being a cheap arse.

I have absolutely no confidence in the BBS02 kit, especially after gorndog's experience of the warranty replacement dying after 4 miles. How long will my new one last? 20km, 200km, 2000km? I think I'd have more luck seeing Elvis or winning the lotto, then having it last 2000km.

rolls, you are such a sook. If you are not ready to take the good with the bad, perhaps DYI ebikes just isn't your thing.

Kepler said:

If you are not ready to take the good with the bad, perhaps DYI ebikes just isn't your thing

Click to expand...

So you are saying that if you put out hard earned cash for one of these, then you should be quite happy with a catastrophic failure in the first 20km?

If you're happy with that, then why don't you put your money where your mouth is and buy this kit off me? Less than 20km. I haven't even peeled the plastic off the motor or the display.

Its hardly catastrophic :lol: Its just a controller that you are getting replaced under warranty and that will take about 10 minutes to fix. Seems like the cost to you just a bit of time. Joys of DIY ebikes and dealing with chinese quality control.

Sure, i will take it off your hands. How much you want for it?

I to have had the exact opposite experience than you, having done over 4000km on the same kit from em3EV. I am using the frame pack as well so Paul tuned mine down to match the battery. I have since set my unit at 18A with my level 9 set to 70% and have been running this way for thousands of Km's with no issues. I believe this is very similar to Keplers settings.

It cost me AUD$660. So that plus whatever postage is to Melbourne.