Motor cuts under load

[wheeliepete]

Your suntour battery should be easy enough to convert if you can cope with some soldering. Open up the case and post some photos of what you find inside. You will need a new bms, but it should be fairly straight forward. DEATH to all closed systems

https://www.ebay.co.uk/itm/Battery-Protection-Board-BMS-PCB-10Packs-36V-10S-Li-ion-Cell-Max-40A-Balance-BSG/122928984391?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

 

[anon4]

Thanks. I will try the 13a controller first. IveI had other issues with this crappy controller so it's possibly just tripping something. If not I happen to have just bought a fantastic gas soldering iron kit from Aldi lol

 

[anon4]

I was reading that the BMS can also be bypassed for discharge. Is this a reasonably safe route, as long as the controller has a low voltage cutoff?

 

[wheeliepete]

I was reading that the BMS can also be bypassed for discharge

Yes, that may be possible, depending on the complexity of the suntour BMS. It would also mean that your charger would still work, which is doubtful if you change out the BMS completely.

 

[anon4]

 

[anon4]

 

[anon4]

Image wont load but basically the BMS is a huge board on top of the whole pack

 

[anon4]

https://drive.google.com/file/d/1Us2dF1W7GK0P5jPkpJ-8rqDemnIWu985/view?usp=drivesdk

 

[peter.c]

ouch that's more than a simple bms odds are it looks for the suntour controller
may be totally locked together 2 way comms if to upgrade you have to change the lot it

 

[anon4]

ouch that's more than a simple bms odds are it looks for the suntour controller
may be totally locked together 2 way comms if to upgrade you have to change the lot it

Strange how it works with no load, or the restrictor plugged in (which goes like 10mph rather than 15.5 for some reason). I still think amp limit. If I lead a wire straight from the negative end to the terminals it will probably know right? How would I get this darned thing out?

 

[wheeliepete]

Hmm, kinda what I expected to see, as peter says, it's gonna have to go. It may seem a little daunting, but under that mess is just an ordinary battery pack like every other one out there. Bonus is there's plenty of room for the new BMS

 

[anon4]

Hmm, kinda what I expected to see, as peter says, it's gonna have to go. It may seem a little daunting, but under that mess is just an ordinary battery pack like every other one out there. Bonus is there's plenty of room for the new BMS

If I get it out can I still use my charge port? And how do I do it?

 

[anon4]

Just desolder the tabs and unplug?

 

[peter.c]

I guess you will not want to give up but if you have to buy a new controller and display and bms or a complete battery only to find a hidden sensor in the wheel it could be a costly nightmare

 

[peter.c]

the charger port will need some kind bms

 

[anon4]

I guess you will not want to give up but if you have to buy a new controller and display and bms or a complete battery only to find a hidden sensor in the wheel it could be a costly nightmare

Its not the wheel it flies with a normal Chinese battery plugged in. Unfortunately its not a frame mount one, also it's hers

 

[anon4]

Is bypassing the negative for discharge not an option then?

 

[wheeliepete]

I don't know of anyone having done this to the suntour system, so you are putting yourself up as a guinea pig on this one, but see no reason it won't work. I doubt there is anything in the motor to prevent this working, you have had that running with a different controller and your chinese battery, maybe a test run on the road with that setup would ensure that all is well.

 

[anon4]

I don't know of anyone having done this to the suntour system, so you are putting yourself up as a guinea pig on this one, but see no reason it won't work. I doubt there is anything in the motor to prevent this working, you have had that running with a different controller and your chinese battery, maybe a test run on the road with that setup would ensure that all is well.

So do I just run wires straight from the battery terminals (which I'm guessing are the end ones that are screwed on) to the terminals for the bike? Or is there something else I have to do?

 

[peter.c]

It is not an option I would risk a battery fire is a spectacular thing it will not go out or a burnt out pcb might cost a small fortune to replace the other option is a yose power battery it is £172.00 delivered for the 14.5 ah + the cost of the new controller and display