Bafang BBSO2 not turning on

[explorer]

I have a beach cruiser with standard brakes that was converted to an e-bike by a local guy that has since moved. It has the BBSO2 with version A controller, the DCP14 color display, and 48 volt shark battery. The bike will not turn on. I ordered another DCP14 display and switch and installed them and the bike will still not turn on. The battery is fully charged and reading 48 volts. Could it be a controller problem?

Is there anyone in Southern California, Orange or Los Angeles County, that can help?

 

[harryS]

I am pretty sure the BBS02 is the same. I have a BBS02. The only time it wouldn't turn on, I had a charged up battery, but the battery connector was loose.

The display doesn't need a controller to turn on. All it needs is battery voltage across two pins, so it makes sense to check that it's getting power.

Test for 48V across pins 1 and 8 in the round 5 pin connector. It's not easy to do, because they're pins. If you don't get power there, go to the main 8 pin connector coming out of the motor. Again, another tricky measurement, unless you have three hands. Hint, have a helper hold the cable.

 

[tomjasz]

Unfortunately, first version BBS02 controllers are now as rare as hens' teeth.

48 volts.

48V is not a full charge. 36V would be 42V, 48V would be 54.6V. As Harry points out it could be a wiring issue. Can you confirm which voltage BBS02 it is?

Check to be certain the sensor is functioning and the brake cutouts are functional. Bothe issues can keep some versions of the firmware from the system turning on. Sharakpacks can also have a bad connection.
Was it a sudden fail with no error codes?

 

[tomjasz]

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[explorer]

I am pretty sure the BBS02 is the same. I have a BBS02. The only time it wouldn't turn on, I had a charged up battery, but the battery connector was loose.

The display doesn't need a controller to turn on. All it needs is battery voltage across two pins, so it makes sense to check that it's getting power.

Test for 48V across pins 1 and 8 in the round 5 pin connector. It's not easy to do, because they're pins. If you don't get power there, go to the main 8 pin connector coming out of the motor. Again, another tricky measurement, unless you have three hands. Hint, have a helper hold the cable.




View attachment 50693

First of all , thank you for the diagram. I checked battery and it is putting out 54.2 volts. I checked the voltage at the display harness and it read 38.1 volts. Plugged in new and existing display and still will not turn on. Any other ideas?

 

[tomjasz]

is the speed sensor flashing when the magnet passes? Are the brake cutouts functioning? First version BBS02 had controller issues. It was updated with a controller with 3077 FET's and that improved on the issues. 3rd version controllers are not compatible. If the speed sensor and brake cutouts are functioning I bet on a bad controler.

Have you ridden the bikes at all? Under what conditions? Can you describe how you road it? By shifting between gears or lots of throttle use?

 

[harryS]

Low voltage cutoff for a 48V battery is set around 40-42V for most ebikes If you're seeing 38.2v, I would say it's too low to start the display. I can put one of my 36V packs, about 41 volts at full charge on my BBS02 and it powers up, but with a low battery icon, If I had one at 38V, I'd try it, but that will have to wait til I run it down them down with a ride. Maybe later this week.

I would suggest trying to probe at the battery connector and see if it's delivering 54,2V when attached to the bike.

 

[explorer]

Unfortunately, first version BBS02 controllers are now as rare as hens' teeth.


48V is not a full charge. 36V would be 42V, 48V would be 54.6V. As Harry points out it could be a wiring issue. Can you confirm which voltage BBS02 it is?

Check to be certain the sensor is functioning and the brake cutouts are functional. Bothe issues can keep some versions of the firmware from the system turning on. Sharakpacks can also have a bad connection.
Was it a sudden fail with no error codes?

It was not a sudden fail. Just wanted to ride bike after a week and wouldn’t turn in. How do I check to see if brake cutouts are functional ? The power side has the female end and can’t get multimeter leads in the tiny holes.

Low voltage cutoff for a 48V battery is set around 40-42V for most ebikes If you're seeing 38.2v, I would say it's too low to start the display. I can put one of my 36V packs, about 41 volts at full charge on my BBS02 and it powers up, but with a low battery icon, If I had one at 38V, I'd try it, but that will have to wait til I run it down them down with a ride. Maybe later this week.

I would suggest trying to probe at the battery connector and see if it's delivering 54,2V when attached to the bike.

the battery is putting out 54.2v at the connector

 

[harryS]

If the battery is putting out 54.2V attached and with the load of the controller, it's a mystery to me why you only get 38V at the display. I would expect a straight thru wire between battery and the display.

By the way, my BBS02 purchased in 2016 from Luna, powers up fine with the brake levers engaged.

 

[tomjasz]

Older BBSxx versions are subject to a fairly high rate of controller problems. I guess I didn't have my thinking cap on when I said check the sensor function. I apologize. Obviously you can't.

If you road the motor hard, not shifting into an appropriate gear as if it wasn't motorized, and took off from a stop on a road gear with the throttle or high PAS mode the old BBSxx likely overheated. Have you ever felt the motor after a ride? I think it's likely a controller issue if all the connectors are OK.

 

[tomjasz]

If the battery is putting out 54.2V attached and with the load of the controller, it's a mystery to me why you only get 38V at the display. I would expect a straight thru wire between battery and the display.

By the way, my BBS02 purchased in 2016 from Luna, powers up fine with the brake levers engaged.

A or B version? 2016 is when they changed. There were three versions. Original model A, model A with updated FET's, and then the BBS02B. B controllers are not backwards compatible.

 

[tomjasz]

By the way, my BBS02 purchased in 2016 from Luna, powers up fine with the brake levers engaged.

There was a firmware version that would not start up with the brakes engaged. I've had several customers with firmware versions that wouldn't start. My first personal BBSHD did the same thing. I've had motors that needed the speed sensor working to start up too. Bafang is notorious with dealers for changing firmware and creating a problem. Like the firmware that recently wouldn't let the motor run with a 52V battery. 07 error.

 

[harryS]

A or B version? 2016 is when they changed. There were three versions. Original model A, model A with updated FET's, and then the BBS02B. B controllers are not backwards compatible.

Doesn't matter to me. It runs fine. Powers up regardless of brakes. No 07 error. I can use throttle and PAS at same time. I guess it better not break.

 

[tomjasz]

J

Doesn't matter to me. It runs fine.

i have 3 2014 36v we ride around a local path. Treat em right and no issues here either.