Overvolting a Pendleton somerby

[richard beadle]

Hi all,
Been lurking for a while slowly building up my knowledge, to the point where I manage to build my own bike, tszd2 500w on a forme ripley 1 mtb. Really enjoyed the process and the results have been great, managing to do a regular 50 mile round trip commute 3 times a week, saving at least 15 quid a week in fuel, happy days.

Now to the point when I got my bike the Mrs wanted one to, she got herself a Pendleton somerby £500 from halfords. It's ok if you like that sort of bike but seriously limited by the puny battery, it's also fairly poor on steep stuff. Yesterday after 27 miles it was pretty much empty and I had to ride it home for her with no power while she rode my bike. Of course now she has tried mine she has become power hungry and realised the limitations of her bike and wow so did I.

So my idea is to up the volts on the bafang rear hub motor, I have a spare hailong 48v 12a battery which I plan to use. I'm guessing the controller will need replacing and I would like some recommendations regarding that, I was thinking this one, with an LCD3 display

http://www.pswpower.com/peng/iview.asp?KeyID=dtpic-2016-3F-39N8.50CQE

I don't know much about these controllers so any help would be most appreciated or any other advice as to potential pit falls.

The priority is to get more range but a little more poke on the steep stuff would also help, not bothered about flat out speed.

Ultimately the whole kit will then be tranfered to another hybrid style bike, once we have decided on one.

Many thanks

Rich

 

[Deleted member 4366]

Volts affect the speed as well as the power. You might find that the motor runs very inefficiently at 48v, but it depends on its present unrestricted speed.

36v would be a better step up for a shopping/ touring bike. 48v would be better as a high-speed commuter, but the rest of the bike isn't really suited to high speed either.

36v will give 50% more power and speed, which would be a substantial improvement. I've converted a few 24v bikes to 36v and all the owners were happy with the improvement.

 

[richard beadle]

Hi Dave, thanks for the response, pretty sure it's already running at 36v have to double check when I get home but I'm 99% sure it's 36v. What are your thoughts on the controller I know you recommend them for the q128.

 

[Deleted member 4366]

If it's already 36v, 48v should be OK. I must have got it mixed up with something else that's 24v. I should've checked.

 

[richard beadle]

Yeah probably would have helped if I had put it in the original description,sorry about that.

What are your thoughts on the controller I picked Dave?

Many thanks

Rich

 

[Deleted member 4366]

That controller should be OK. I doubt that you'll be using level 5 much though.

Another thing that you'll probably have to give some attention to is the gearing, which will most likely be too low when you increase the power. I have 8-speed DNP freewheels with 11T top gear, which will most likely fix that. £20 inc postage.

How many teeth on the standard top gear?

 

[richard beadle]

That controller should be OK. I doubt that you'll be using level 5 much though.

Another thing that you'll probably have to give some attention to is the gearing, which will most likely be too low when you increase the power. I have 8-speed DNP freewheels with 11T top gear, which will most likely fix that. £20 inc postage.

How many teeth on the standard top gear?

13t on top gear 32t bottom 8 speed by-dnp slick shift.

Dunno about that level 5 Dave, I think that extra 250w my mrs experenced on my bike has driven her power crazy. Although I dare say that will soon end in the first week when she falls off and either never rides it again or gets me to put it back how it was lol

 

[richard beadle]

Like I said before though, top speed isn't a priority it's main increased range and hopefully a bit more grunt up hill, she wants.

 

[Deleted member 4366]

You'll see what I mean about the gearing!

Check whether the motor is sensored or sensorless. If sensored, a KT sine wave controller will be fine, otherwise you need a square wave one.

 

[richard beadle]

You'll see what I mean about the gearing!

Check whether the motor is sensored or sensorless. If sensored, a KT sine wave controller will be fine, otherwise you need a square wave one.

Ok Dave how do I check this I've reached the limit of my knowledge. Do you mean the pas sensor ? It's a bafang motor, there is a serial number on it but I can't see any model number.

 

[richard beadle]

You'll see what I mean about the gearing!

Check whether the motor is sensored or sensorless. If sensored, a KT sine wave controller will be fine, otherwise you need a square wave one.

Ok so I stopped being lazy and did some further digging, from what i understand you are referring to a hall sensor and if my motor has one it should have 7/8 pins in the moulded connector coming from the motor, is this correct Dave?

 

[Deleted member 4366]

Three thick wires and at least 5 thin wires for sensored - or a 9 pin connector. Sensorless is normally only the three thick wires or a three pin connector, though sometimes they have additional three thin wires for a speed sensor.

 

[richard beadle]

Cheers Dave it's a nine pin connector, 3 pins slightly longer and thicker which I assume are the phase pins. I'll get on with orderering the sine wave controller.

Many thanks