Woosh Revisiting my first conversion

[Peter.Bridge]

So my very first conversion was 2 years ago. I fitted a Woosh XF08c kit to a Claud Butler step through bike (with rim brakes !)

It has a 36v 20Ah rack battery with I believe a Lishui 18 amp controller built into the battery housing



I was very pleased with it and my niece "borrowed" it to use at University.

She has been out riding with my sister in the North York Moors and on some of the longer hills at full power the motor has been cutting out (I'm assuming the controller is overheating). This used to happen to me before my niece borrowed it



If they take a break it starts working again fine

The other thing that has become a bit hazardous is the rim brakes, particularly down some of those hills !

So my plan is to swap donor bike to one with disc brakes

Would it matter if the new donor bike has "27.5in" wheels (motor wheel is 700c)

trek marlin 5 small mountain bike

this bike is in good condition and full working order however its been sat a while so maybe benefit some tlc small frame,27.5 wheels, hydraulic brakes...

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Ladies Hybrid Bicycle (Carrera Subway One)

• Carrera Subway 1 Womens Hybrid Bike - Grey 16" • Shimano Tourney TX 3x8 (24 speed) • Brake Type : Mechanical Disc Brakes • 16" frame • Excellent condition (hardly used)

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What should I do with controller ?.(My niece is 60-65 kg)

Replace with like for like ?
Mount controller outside battery housing (cooler ?)
Get 9 MOSFET or 12 MOSFET controller + matching display ?

 

[Nealh]

I found when my S06S started cutting out due to thermal cutout that it happened more often and quicker once under pressure.
Mounting outside will likely not make much difference, after mine cut out I fitted another heatsink , two small 5v fans and supply but tbh it made little difference.
A larger mosfet model likely won't fit inside the battery compartment (though one can check) so it will have to be exterior sited.

 

[saneagle]

So my very first conversion was 2 years ago. I fitted a Woosh XF08c kit to a Claud Butler step through bike (with rim brakes !)

It has a 36v 20Ah rack battery with I believe a Lishui 18 amp controller built into the battery housing

View attachment 62768

I was very pleased with it and my niece "borrowed" it to use at University.

She has been out riding with my sister in the North York Moors and on some of the longer hills at full power the motor has been cutting out (I'm assuming the controller is overheating). This used to happen to me before my niece borrowed it

View attachment 62769

If they take a break it starts working again fine

The other thing that has become a bit hazardous is the rim brakes, particularly down some of those hills !

So my plan is to swap donor bike to one with disc brakes

Would it matter if the new donor bike has "27.5in" wheels (motor wheel is 700c)

trek marlin 5 small mountain bike

this bike is in good condition and full working order however its been sat a while so maybe benefit some tlc small frame,27.5 wheels, hydraulic brakes...

www.facebook.com

Ladies Hybrid Bicycle (Carrera Subway One)

• Carrera Subway 1 Womens Hybrid Bike - Grey 16" • Shimano Tourney TX 3x8 (24 speed) • Brake Type : Mechanical Disc Brakes • 16" frame • Excellent condition (hardly used)

www.facebook.com

What should I do with controller ?.(My niece is 60-65 kg)

Replace with like for like ?
Mount controller outside battery housing (cooler ?)
Get 9 MOSFET or 12 MOSFET controller + matching display ?

You need to establish what causing the cutouts before changing anything. If the LCD goes off, it's the battery, and if it stays on, it's the controller. Which is it?

You can use the 700C wheel as long as it fits in the space with your tyre of choice. You need to take measurements to be sure there's clearance behind the chainwheel and at the top of the seat-stays.

 

[Peter.Bridge]

You need to establish what causing the cutouts before changing anything. If the LCD goes off, it's the battery, and if it stays on, it's the controller. Which is it?

You can use the 700C wheel as long as it fits in the space with your tyre of choice. You need to take measurements to be sure there's clearance behind the chainwheel and at the top of the seat-stays.

The LCD stays on

 

[saneagle]

The LCD stays on

Hmmm! I've run many controllers at much higher currents than what I was supposed to. I never had one overheat because of that, despite installing them in spaces where they didn't get much air. The only time I got overheating was when the motor's were too fast for their power, so they ran inefficiently and drew max current all the time.

My thinking is that there must be some other cause of your problem, like connection issue or something. Did you check inside the box and the motor connector?

 

[Peter.Bridge]

Hmmm! I've run many controllers at much higher currents than what I was supposed to. I never had one overheat because of that, despite installing them in spaces where they didn't get much air. The only time I got overheating was when the motor's were too fast for their power, so they ran inefficiently and drew max current all the time.

My thinking is that there must be some other cause of your problem, like connection issue or something. Did you check inside the box and the motor connector?

Yep motor connector right to the line, not checked inside the battery compartment that houses the controller. This is a 201 rpm motor i think (no load unrestricted speed on full battery 19mph)

I have had this before on completely different e-bikes with different batteries and different controllers and different motor, where on a very long steep hill at high power the assist either reduces drastically or stops completely and the controller is too hot to touch. That is hauling me (105kg) up a long, steep hill. I was a bit surpised what I had assumed was the same was happening to my niece who is much lighter, but as @Nealh mentioned, maybe I had "weakened" the mosfets by overheating when I had the bike

eta - this is happening at low speeds 5-6 mph

 

[saneagle]

Yep motor connector right to the line, not checked inside the battery compartment that houses the controller. This is a 201 rpm motor i think (no load unrestricted speed on full battery 19mph)

I have had this before on completely different e-bikes with different batteries and different controllers and different motor, where on a very long steep hill at high power the assist either reduces drastically or stops completely and the controller is too hot to touch. That is hauling me (105kg) up a long, steep hill. I was a bit surpised what I had assumed was the same was happening to my niece who is much lighter, but as @Nealh mentioned, maybe I had "weakened" the mosfets by overheating when I had the bike

eta - this is happening at low speeds 5-6 mph

OK, 5-6mph is a bit slow. I'd be surprised if the motor wires coming out of the controller haven't melted. You should check them if you can.

 

[Nealh]

That was my issue with the thermal cut outs, my cadence is too low going up hill and I don't have great stamina strengths to really go for it. I'm a plodder who can cover great distance though.
A 9 mosfet controller upgrade made the difference for me.