walvolt

[walvolt]

I have a 6 year old Volt Pulse ebike. It has a bafang rear hub fun 8 motor. The lcd meter is 5 wired and the controller is unlabeled and so not identified. I have been experiencing intermitent power supply to the extent that the bike is unusable due to unreliability. It seems from pedelecs' forum that it is a common problem. The battery has been replaced last summer. Are there any diagnostic ebike mechanics in the Uxbridge/Hillingdon area. I am loathe to buy new parts blindly (meter, controller,etc.,) unless the problem source is identified. Today I had the bike indoors to refit brake caliper. Also looked at battery terminals to ensure they were in contact and clean. Tried the bike on the thumb throttle and it engaged the power. Tried it again, it went ok. Third and almost immediate attempt produced no result! That's been the pattern of things lately. Bike is stored in garage and never used in rain.
Any advice or suggestions would be much appreciated.

 

[Fat Rat]

Hi welcome
Good luck with your problems

 

[Nealh]

Walvolt intermittent power is commonly down to power from the battery so check the connections again and at the controller, also check the motor hub connector and make sure it fully pushed together.
The PAS sensor can also cause your issue make sure the magnet disc is firmly fixed and only rotates with the pedal crank also make sure the gap from it to the sensor is < 2mm.
If non of these help out we can guide you to try and see if there is an electrical fault elsewhere using a meter.

 

[Benjahmin]

Intermittant faults are a right barsteward aren't they?
As Neal said, go round all the plugs you can find and make sure they're fully pushed home.
When you get the no power condition is the lcd display still live?

 

[walvolt]

Neal and Benjahmin, thanks for the advice. Am just about to follow your suggestions. Neal, (Neahl?) I also have a new 5 magnet crank ring and will replace the original that had broken a year or more ago and recobbled together. Benjahmin, meter appears to be functioning well with no error flashes at any time. Would you believe it.? The beast fired up this morning many times without fail. Was kept overnight in house. Wonder if this is significant? Will report on progress (progress hopefully). By the way, the meter remains live when power is lost.

 

[Nealh]

If the meter/ bar display doesn't loose power then you can rule out a battery connection issue, the display receives a 5v signal via the controller then sends a comms signal back to said controller to say all is ok.

As ben has said sometimes intermittent faults can be difficult to find, but in most cases can be attributed to a wire issue. Painstakingly go thru each wire connector, disconnect each one and give the wire/connector on both sides a gentle tug/wiggle to ensure nothing is loose. Bullets and jst type pin connectors now and then need a little fine crimp to ensure good contact.

I recently had an issue with my front light/horn combo where the horn was intermittent, I suspected a wire break in the wiring as it was kinked and didn't feel right after splicing in a new piece of wire the issue still persisted. I then turned my attention to the jst pin connector and found a wiggle identified a false connection, crimping the female lug has ensured a better connection.

Certainly look at the pass first to ensure it is working.

When as you say the "beast fired up this morning" is that again just throttle or PAS as well ?

 

[walvolt]

If the meter/ bar display doesn't loose power then you can rule out a battery connection issue, the display receives a 5v signal via the controller then sends a comms signal back to said controller to say all is ok.

As ben has said sometimes intermittent faults can be difficult to find, but in most cases can be attributed to a wire issue. Painstakingly go thru each wire connector, disconnect each one and give the wire/connector on both sides a gentle tug/wiggle to ensure nothing is loose. Bullets and jst type pin connectors now and then need a little fine crimp to ensure good contact.

I recently had an issue with my front light/horn combo where the horn was intermittent, I suspected a wire break in the wiring as it was kinked and didn't feel right after splicing in a new piece of wire the issue still persisted. I then turned my attention to the jst pin connector and found a wiggle identified a false connection, crimping the female lug has ensured a better connection.

Certainly look at the pass first to ensure it is working.

When as you say the "beast fired up this morning" is that again just throttle or PAS as well ?

 

[walvolt]

As I indicated earlier, have just changed the magnetic ring (pas?) and it fired up ok on both pedal power and throttle. However tried again later and .. . No power. The motor power cable connector I had pushed hard together so as it previously worked, should rule that out.
Break cut-outs: the rear brake cut out is disabled as I am waiting to receive a new Reed switch to connect into that circuit. I have left that circuit open. However the front break cut out is as supplied from new and never tinkered with. I mention this as I definitely squeezed the front brake lever just prior to the last and failed attempt. Might it be worth backing off the cutout adjuster?
Finally, I shall bite the bullet, drag out the controller and check each of the connectors. Thanks again for your help. Grateful walvolt.

 

[Nealh]

Brake sensor and throttle can cause problems disconnect them from the controller and ride just with PAS to see if the intermittent problem goes away.
Then if it works ok again connect the brake sensor again and try it out, last of all connect the throttle. That way you may be able to pin point the issue if it is a peripheral issue.

 

[Benjahmin]

Also check that the new pas disc is firm on the shaft and constantly within 1-2mm of the sensor.

 

[walvolt]

Last night I removed the controller with the mass of wiring and found no loose connections, wiggled and pushed together all connectors a bit and then resisted them. To my disappointment, power was still inactive despite several attempts . . . Tried again early this morning and unbelievably it worked and continued to do so throughout the morning !?* Road tested it this afternoon and all functions ok. That I think shows all components function (if only at some times) and support your knowledge that most ebike faults are wiring/connector related. I shall store the bike in my garage tomorrow after retesting. If there are problems after storing it there (humidity?), I shall take your advice and disconnect the throttle and brake cutouts and see what happens.
Once again, many thanks Neahl. Fingers crossed!

 

[Nealh]

Somewhere in all of that is a wire/connector fault. It may be a broken wire that now and then contacts and only needs a slight bump/movement to cause the issue or a false connector pin contact.
Certainly ride without the Brake and throttle for a while to see if all is well.

Do check out the three phase wires, if bullets they can be problamatic and need crimping, otherwise theoretically the wire/connetion issue I would say is one of three , PAS , brake or throttle.
It is impossible to pin point which without thorough detailed examination of the wiring .

 

[walvolt]

Will bear the 3 phase connectors in mind for any future problems. The feed cable to motor has a 3 pin Julet connector with skinny little pins.

 

[Nealh]

Will bear the 3 phase connectors in mind for any future problems. The feed cable to motor has a 3 pin Julet connector with skinny little pins.

Have a look inside the connectors for any sign of moisture oxidisation.

 

[walvolt]

Shall do at some point sooner rather than later. Thanks.

Also Benjahmin, new magnetic disc is fitted and working