BBS01B 250w to 350w

[whiteturbo]

I have two bikes with Bafang 250's and generally i'm happy with them. When i first got one i tried to up the amperage to, i think it was 17 or 18 amps, to turn it into a 350w but got error messages so gave up with that idea. A year later and i am thinking i need more power but not at too much expense, I looked at getting a BBS02 500w but the 750w is same price and anyway money is tight at the moment. So I wondered if i bought a 350w controller(about £80) would it make a noticeable difference as i know the only difference between the 250w and the 350w is the controller. Or should i just make do with what i have until i can afford a BBS02 xxxw.

 

[anotherkiwi]

15 X 42 = 630
18 X 42 = 756

125 W more hot off the charger. I think you would get more kicks from a 48v motor but you need a battery and that is a whole new budget.

 

[peter.c]

I now have the 500watt 25 amps in my latest off road build in this spec even at 36 volts with a nearly flat battery it has more usable power across the range the pulling power on a full charge the only adjustment needed was the keep current. This is the spec that was originally intended for before it was restricted

 

[Footpath]

Hi everyone, I currently have a Bafang front hub 250v 36w brushless Hall sensor motor with 35Nm. I have a 48v 10ah battery and getting a new controller. I’ve had some really good advice and guidance from members on this forum so far.
My question is- if I upgrade to a 48v 500w Bafang motor, with more Nm, do I just need to buy a new hub or do I also need to put in a hall sensor etc myself? Basically I have the ability to do a straight unplug, un bolt, re bolt, replug and re program controller and away I go. Is it as simple as that? I hope so! If so, can anyone suggest a link for a suitable. Motor? Thanks in advance

 

[wheeliepete]

If you are getting a new 48v controller you can run your 36v motor at 48v, giving you increased torque and speed. Be aware that your battery is fairly low capacity and depending on the cells inside it, may not be able to run at high current very well. What controller have you ordered?

 

[Footpath]

Hi, it’s a KT 48v 350w controller, but I realise I’d have to re order and get a 500w one. Is that right?

 

[Footpath]

It’s the-
48V 350W Brushless DC Sine Wave Controller ebike Electric Bicycle Hub Motor Controller with right output

 

[Footpath]

I only ride for 20 - 30 minutes per day and it’s mostly flat. The new controller is 17 amps.

 

[wheeliepete]

Sorry, I didn't connect you with your trike thread, I'm with you nowSo you are already running with a 36v motor and KT 48v 15amp controller. You should notice some improved torque with the 17 amp controller you've ordered, 20 amp would give a little more, but if you are riding on mainly flat terrain, then I'm not sure how much. Motor watt ratings have nothing to do with performance, so don't be mislead by this. Your 36v 250 watt will run faster than a 48v 500 watt with the same winding rating, in your case 10, at 20 amps 48v. If you want more speed, then you need a faster wound motor, not higher watt rating, but torque decreases as motor speed increases.

 

[Footpath]

Thank you Wheeliepete, good advice. I’ll stick with what motor I have then... maybe I get a 20 or higher amp controller? What would you recommend...20, 25A? Cheers

 

[anotherkiwi]

The sweet spot for many 250 W rated motors is 17-18 Amps. Any more and you have to start thinking about heat issues. Not on the flat but if you ever meet a steep enough hill that is when you will start having issues.

20 Amps x 54.6v (hot off the charger) = +1 kW

Plastic gears start to melt at about 160°C, wire insulation gets iffy over 120°-130°C

 

[Footpath]

Hi Anotherkiwi, thanks for that. I didn’t take overheating into account. I’ll see how it responds to my new 17a controller. Cheers