BBS02 got error 07 before, now error 12

[greeneyes]

Two weeks ago I tried charging my 52V battery to 100% for the first time (I was using 85% until then). It worked fine for maybe half hour but then it started to occasionally show error 07 - high voltage protection. But after a few minutes it started to work again. Then I got the error again. Then it worked again. At one point it refused to work for maybe half an hour, even though the voltage was like 54V, which is odd since I regularly used it at that voltage before. Once it got below 53V, it started to work fine. Except it showed the error for a few seconds when it was at 48V. This was all in one day, and didn't repeat since then.

Today I tried charging to 100% again. First hour was fine. Then I started noticing that the motor shuts off for a few seconds sometimes, even though I'm pedalling and the display shows I'm actually using quite a lot of power. And the wattage indicator seemed to show nonsense, no way was I using 750W going 15kmh on an easy slope. Then I got error 12 - fault in the current sensor in the controller. It kept showing the error nonstop, but I was occasionally still able to use the throttle despite the error. Sometimes even the PAS kicked in. However, the throttle used too much current, I was practically doing wheelies the moment I touched it. It worked maybe half of the time I tried it. Eventually the battery got down to 50V and suddenly the error was gone and everything worked as normal.

I have a BBS02 750W and a 52V battery from em3ev. I use the grintech satiator charger. I have 800km on the bike. I did program the controller, but only to make it weaker - lowered the maximum current to 18 iirc, lowered the starting current, made the lower PAS levels a bit weaker. I usually only use the PAS and try to conserve battery. I checked for pinched cables and everything seems fine on that front.

Is there some controller problem in the hardware or could it be software? Somehow it can't handle higher voltage, even though it works at first.

[AZguy]

Those symptoms are a bit all over the place

Some BBS's have firmware that doesn't play well with 52V batteries and throw overvoltage errors above around 55V but hard to point to that with any certainty with what you have going... maybe it's a factor and you have other issues too?

How are you measuring voltage? Most voltmeters that don't cost hundreds of dollars aren't super accurate so you may need to take that into account... many have a stated accuracy of 0.5%-1% new (they do drift with age) and sometimes that's of the full scale but even if just at 0.5%-1% of 55V it still works out to ~0.25-0.55V which when looking at battery state is bordering on relatively significant

[greeneyes]

I'm measuring via display and connecting to the battery via bluetooth, the app shows voltage as reported in the bms. I don't have a multimeter since I'm out on a trip the past 2 weeks. The display reports voltage about 0.3V lower than the bms. But the voltage reported on the display seems to change from second to second, plus minus 0.4V from the average.

[stts]

Dang. Strange bunch of errors. Makes me think water got into the motor. Then you get all kinds of conflicting error displays. And water is very bad news when a battery is plugged into it. Even when just sitting there's the potential for continued arcing and sparking that eats at the circuits. Myself I would unplug the battery and pick a time to open up the motor to have a good look around and even heat it up with a hair dryer to promote drying out. Then plug it back in after a few days to see if the errors vanish. People have been discovering water getting into these motors with very bad effect. So it's worth an investigation to halt that kind of damage.

[greeneyes]

Wouldn't it be happening all the time if it was water? I only cycled in the rain maybe twice and not for long.

[stts]

Water is random. If there is alot, then the damage going on will probably end up with a hopeless situation. If its just a little moisture and humidity, the battery current will slowly eat at the circuits. With the arcing and sparking triggering a variety of errors. Yup, Id be unplugging it right now. That stops damage in its tracks. Then look to be opening things up at the first opportunity. You don't take chances when water is suspected. Because it ruins things in very short order.

[greeneyes]

I guess I'll try to see if aliexpress will accept a return, there is supposed to be a one year warranty. Is it probably just the controller? But I voided the warranty by programming it...

[stts]

I got kicked off Aliexpress for demanding warranty on stuff that didn't run 5 minutes. Now I cant get anything at all from them. Makes me sad that I demanded warranty. Their stuff is super cheap. Now I get nothing at all. :( I will eventually get somebody else to order stuff for me. But so far people run from me when I ask them too. As for programming void, there's no way they would ever know you programmed it. They only know what you tell them.

[73Eldo]

So it is stable if its below a certain voltage like that 85% you have historically done? If so then it seems like you just have hardware or firmware that doesn't actually like a 52v battery. Or is still not acting right at the lower voltages? That is where I'm having trouble following whats actually going on.

[stts]

As voltage rises, more arcing and sparking goes on. But with enough time, even a 9 volt battery will eventually eat up a wet circuit. It might still be saved if he keeps it unplugged until he knows it's dry as a bone. I hate that potting they do in the controller because its never really sealed and capillary action grabs moisture and sucks it right into the circuits. That gloppy never hardening silicone or just clear dielectric paint is a way better protector from moisture. If I dig my potting out, I will paint the circuit for protection. From the pics I saw, it looks like they quit using potting on the M line of motors. Very smart upgrade.

[greeneyes]

It's stable below 85%. But once I charge to 100%, it works at first but starts to show errors even below 85%.

[greeneyes]

On Aliexpress they said it doesn't support 52V and that I damaged the controller by using a 52V battery... If I find no water, can I just buy a different controller or do I need to get a different motor for this battery?

[stts]

Hah, 4 more volts and you damaged the controller. Bwahahaha. Yea, Aliexpress gave me every lame excuse in the book to get me to go away but I pressed them hard and got a refund. But then they kicked me out, so it was just a bad scene from all viewpoints. But, open that thing up and hair dryer the crap out of it. prop it up for an hour to let the insides get a long hot tornado. Then let it dry out overnight. Heat it the next day and let dry to really make sure. Then plug it back in to see if your errors go away. An yes you can get a new controller for it. But lets see if you can get this one to work first. You can also unscrew the rotor windings section to dry it out too. There are youtubes that show the whole dissasembly process. It can be moist in all the wrong places even if you dint see any water. Just depends if you know the signs of trouble. When in doubt, post pics so we can see too and advise.

[AZguy]

A different controller might address things, if and big if the high amperage wiring has no issues (I'm not so sure based on your descriptions)

However if you are confident in the high amperage wiring and are ready to pull the trigger on a new controller I'd try reflashing firmware that supports 52V battery... nothing to lose at that point...