Summary E-Assist & Hiatus

I've been using Rover II with the Bafang BBSO2 E-Assist Kit from Luna for the past couple of months putting on well over 1000 km with many daily rides of 40KM or more. Sorry I can't give you exact distance as the Odometer on the 750C Display has a nasty habit of resetting if you hit the wrong button and there is no way to re-input the correct reading. I have solved that issue by remounting my old Bell Bike Computer as a backup. I had to mount it at the base of the steering arm as I found there was interference between sender and computer if it was mounted close or above the 750C Display.

Generally really pleased with the BBS02 Kit, but have a few issues, mostly solved.

Starting with Luna's 750C Color Display. This is a BETA unit and hope there will be a firmware update in the near future.

Luna 750C Display is very readable speed and watts except with sun glare. Mounted on a handlebar extender mounted to left handle, above brake, throttle, and Level Assist toggle. Smaller text items vibrate too much while riding for me to generally read. Two Green circle graphs glow around Speed and Power when moving- Questionable value 

1. The Clock feature is erratic, randomly deciding to change the time when the unit is shutdown. Battery installed or not seems not to matter. When operating it seems stable
2. The screen black w white text and coloured graphics is hard to read under bright/glare conditions.
3. Watt meter (which I prefer over amp) needs either finer calibration or ability to set sensitivity. I use Level 1 Assist which typically draws an average on level conditions of about 70w but it bounces/jumps up and down from 0 to 26 to 49 to 75 to 96 to 122 (approx. in those spacings). A more stable average reading would be more realistic. The Graph is even more dramatic in its movement at this level of use. At higher watt draw all seems a bit more stable but no one on e-assist is going to be running consistently at several hundred watts...unless a bear is chasing you
4. No USB outlet for cell or headlights.
5. No cadence monitor although the motor has a cadence sensor in it. Part of the PAS.
6. Inability to input Odometer readings. Trip Odometer does not reset to zero unless you start riding immediately after resetting
7. Screen scratches easily. Anti scratch shields makes reading even more difficult.
8. No clear outline of how/if firmware can be updated.
9. Many settings listed that have no apparent function/effect for the BBSXX motors.

Learned a few things about troubleshooting problems with the BBSO2. First off Luna was quick and knowledgeable assisting after I opened a 'trouble ticket'. The ticket had an auto answer immediately and a followup email addressing the issues within 24 hours during weekdays.

Luna's Forums had some of the answers I needed, but I had not looked close enough initially. Other, when diagnosed as new was quickly added to the forums.

My first problem showed up as a sudden shut down and refusal of the unit to accept a charge and not start up.

The initial problem was probably caused by me not connecting/disconnecting the battery charger properly. Each battery system/charger has very specific orders to follow and they were posted in the forum. I just did not find them in time to follow properly. The resultant connection 'sparks' had caused my battery management system (BMS) to 'trip'. 'Jump starting' the battery per the forum corrected that issue, but like many intermittent electrical problems I still had something unresolved.

Strange behaviour continued. Unexplained shutdowns, sudden surging of the unit to high watt draw without using the throttle or the pedal. I looked and looked finally noting arc burns on the cradle connection posts. Cleaned and reinserted battery. Seemed to work okay, but still unexplained shutdowns. Noted on one shutdown, unexplained bouncing of the voltage 36-51-36-40. Was stumped.

Battery connector prongs in base of cradle

Prongs had arcing marks indicating poor connection

Placed two velcro straps under cradle to hold battery tighter. Note round locking hole at right end of cradle. If battery not inserted fully into cradle, locking pin can simply deflect cradle back appearing battery locked when in reality is not.

Battery inserted after battery contact clamps  were bent (carefully  w screwdriver) to more firmly grip the cradle contact prongs. Velcro straps around battery and cradle

On Luna's suggestion carefully bent the contacts on the battery so they would grip the cradle contacts more positively. Then further used two velcro straps under the cradle and around the battery to reinforce battery/cradle contact.

That solved the issue. No problem since. Hard to believe it was that simple. I was ready to start ripping battery cases and controllers apart. Vastly relieved and very impressed by the email and forum support I received.

Been out riding pretty much every day and love the operation. Runs very smooth and quiet. Using the stock Luna program settings for now and cruise at around 22kph L1 and sometimes L2 assist. Rarely use throttle. Charging battery on lowest charger setting to 80% except once a month to 100% to allow BMS to balance cells.

 My runs are 40-50 km max and not running out of power. If going further charge to 100% just prior to run.

So that's it for Bent on a Budget for the time being. I'm taking a hiatus for the rest of the summer and will post again when I have something noteworthy.

Enjoy the ride!