Upgrading hub motor

Hux

Finding my (electric) wheels
Oct 8, 2019
19
1
I would like to swap my rear fat bike 250 hub motor for 500w for a bit more power going up hill. Can I get away with just swapping the motor? Or do I need to swap any other parts at the same time, like the controller and LCD display

Im told the current kit is Bafang!
Has anyone else done this before?
 

Woosh

Trade Member
May 19, 2012
12,025
9,198
Southend on Sea
wooshbikes.co.uk
it's a expensive upgrade.
The 500W version of the Bafang G06 runs on 48V.
You need a new motor, LCD, controller and battery.
 

Hux

Finding my (electric) wheels
Oct 8, 2019
19
1
it's a expensive upgrade.
The 500W version of the Bafang G06 runs on 48V.
You need a new motor, LCD, controller and battery.
Thanks for the response, why do I need to swap the battery
 

Woosh

Trade Member
May 19, 2012
12,025
9,198
Southend on Sea
wooshbikes.co.uk
Thanks for the response, why do I need to swap the battery
that is often the case. You need 48V 12AH minimum to run the 500W G06, better with 48V 15AH.
What capacity / voltage battery do you have at the moment?
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
8,290
3,121
56
West Sx RH
Simply getting a 500w hub won't give you any more power as you will still be using the same controller current, your best option is to show us a pic of your controller.
A new controller with more current will give you more watts at the wheel ( if the battery is capable ) and you can still keep your existing hub, again show us a pic of your battery and tell us which cells are used.
 

Hux

Finding my (electric) wheels
Oct 8, 2019
19
1
Simply getting a 500w hub won't give you any more power as you will still be using the same controller current, your best option is to show us a pic of your controller.
A new controller with more current will give you more watts at the wheel ( if the battery is capable ) and you can still keep your existing hub, again show us a pic of your battery and tell us which cells are used.
 

Attachments

Hux

Finding my (electric) wheels
Oct 8, 2019
19
1
I have no idea what cells are in the battery!
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
8,290
3,121
56
West Sx RH
Ah yes, I now remember your bike was in a thread the other day.
Can you post a link again to the bike then we might be able to see what the battery cell specs might be. Your controller is a Bafang compatible one that works with 961 lcd, at 15 amps max is should put out about 430w at the wheel. If the battery was capable you could use a 17- 22a controller for more current but it does need to be Bafang compatible. Until you know the battery specs it could be a waste of time and money.
 
  • Like
Reactions: oldgroaner

Hux

Finding my (electric) wheels
Oct 8, 2019
19
1
Specifications
1. Frame: Alloy 6061,Suspension frame
2. Fork: Alloy suspension
3. Handle/Stem: Alloy PROMAX
4. Rim: Alloy 6061# double wall rims
5. Tire:20*4.25inch fat tire, KENDA K1032
6. Battery:36V10.4Ah lithium battery, Removable battery
7. Motor:brushless,DC motor,rear drive 36V250W
8. Display:LCD display, 5 level PAS speed
9. Controller:36V, brushless hall controller
10. Brake:F/R disc brake, ZOOM
11. Derailleur Shimano
12. Hubs: Shaft Hubs + Quick release
13. Front round light included
14. Fenders included
15. Luggage Rack
16. Black wheels
 

Hux

Finding my (electric) wheels
Oct 8, 2019
19
1
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
8,290
3,121
56
West Sx RH
Very little spec to the battery except it is 10.4ah which probably suggests it is a 10s4p config and likely uses something like Samsung 26F or J cells in which case the they are maxed out with the current controller.
 

Hux

Finding my (electric) wheels
Oct 8, 2019
19
1
Very little spec to the battery except it is 10.4ah which probably suggests it is a 10s4p config and likely uses something like Samsung 26F or J cells in which case the they are maxed out with the current controller.
Thanks, so would I need a better battery if I upgrade the hub motor ?
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
3,094
929
Basildon
You could probably go to 18 amps OK. In the old days when batteries were crappy - long before we had nice Samsung and Panasonic cells, I often increased the current to 18 or 19 amps without any problems. The increase in current has a proportional affect on torque and power.

The good news is that the cost to increase current is zero. You only need to add a blob of solder to the shunt, assuming that you have a wire one.

The shunt is normally a wire hoop, like a staple, and it often sits behind the end-plate of the controller, so is easy to access. The idea is to put a blob of solder on 20% of its total length. Sometimes they already have a blob from the factory, so you need to lengthen it to reduce the clear length by approx 20%. Don't overdo it. 30% is about as high as you should go. Here's a picture of one. You can see two blobs, one on each leg, totalling about 40%.


If you have a solid state one, you have to solder another one with 1/5 of its value over the top of it. Say you have 05 written on it, you get another one of the same size with 01 written on it.

 
  • Like
Reactions: AlanRHB and Hux

Nealh

Esteemed Pedelecer
Aug 7, 2014
8,290
3,121
56
West Sx RH
As I mentioned you don't have to change the hub motor, if you want more power you need more current.
 

Benjahmin

Esteemed Pedelecer
Nov 10, 2014
1,446
896
65
West Wales
Listen to these guys, you do not need a new motor. The 'power rating' of a motor is misleading B.S. The power consumed by a motor is determined by what the controller gives it, it's a bit like a tap, you need a bigger tap to get more flow.

What vfr400 is suggesting is a freeby workaround, you just need a soldering iron.
Nealh is suggesting a new controller that has a bigger tap in it (though this can come with connection complications).

However, a bigger tap can only give more flow if the supply capacity is there. This is why the battery is mentioned. Not all battery cells are equal. Some cells are high capacity (bit like a marathon runner), others are high flow ability (bit like a sprinter), but the two don't come together in the same cell. Hence trying to ascertain what cells are in your battery to see if it's capable of giving the higher flow your bigger tap can deliver.
Bit of a laboured metaphor, hope it helps.
 
  • Like
Reactions: AlanRHB and POLLY

Woosh

Trade Member
May 19, 2012
12,025
9,198
Southend on Sea
wooshbikes.co.uk
6. Battery:36V10.4Ah lithium battery, Removable battery
there is no way you can get the best out of the 36V 250W G06 with this battery leave alone using it with the 500W G06. You can also damage the battery easily when using a low capacity battery.
The Chinese grade their motors on the basis of continuous power. If it says 250W on the label, you can pump 250W into it all day, the mass of the motor will dissipate the heat without burning the coils or the sensors. 350W motors have thicker wires, lower stalling resistance. 48V 500W motors have thicker wires and usually have more turns in each coil so gives higher torque at low speed and better acceleration.
Typically, when the motor is labelled as 250W, the maximum peak power is double that. Your controller and battery need to be paired to the motor so that they work well together. For example, 250W motor can peak at 500W, the controller should be 14A-15A 36V. 350W motor peaks at 700W, controller should be 18A 36V. This is a popular choice for manufacturers, they simply ask for 350W grade motors for use as 250W.
500W motors are suitable for offroading where you would expect high, short gradient, high acceleration. The controller would be 48V 20A.
If you have a 36V 15A controller, then choose a battery which does not get damaged at that current continuously. That's belt and braces. As a rule of thumb, 1.5C. If C is 10AH for the battery, then 1.5C is 15A for the controller. If your motor is 250W then 36V 10AH is the minimum required.
If you want 500W motor then you'd need 48V 14AH.
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
3,094
929
Basildon
there is no way you can get the best out of the 36V 250W G06 with this battery leave alone using it with the 500W G06. You can also damage the battery easily when using a low capacity battery.
The Chinese grade their motors on the basis of continuous power. If it says 250W on the label, you can pump 250W into it all day, the mass of the motor will dissipate the heat without burning the coils or the sensors. 350W motors have thicker wires, lower stalling resistance. 48V 500W motors have thicker wires and usually have more turns in each coil so gives higher torque at low speed and better acceleration.
Typically, when the motor is labelled as 250W, the maximum peak power is double that. Your controller and battery need to be paired to the motor so that they work well together. For example, 250W motor can peak at 500W, the controller should be 14A-15A 36V. 350W motor peaks at 700W, controller should be 18A 36V. This is a popular choice for manufacturers, they simply ask for 350W grade motors for use as 250W.
500W motors are suitable for offroading where you would expect high, short gradient, high acceleration. The controller would be 48V 20A.
If you have a 36V 15A controller, then choose a battery which does not get damaged at that current continuously. That's belt and braces. As a rule of thumb, 1.5C. If C is 10AH for the battery, then 1.5C is 15A for the controller. If your motor is 250W then 36V 10AH is the minimum required.
If you want 500W motor then you'd need 48V 14AH.
In principle, that's right, but we know from actual experience gained over many years that there wouldn't be any detrimental affect from soldering his shunt a bit.

I've personally run 250w ebike motors that came with 24v 12A controllers at 48v and 18 amps without anything burning or going bang. That's 3 times as much power! Here, we're talking about 20% more.

It's similar with batteries. It's true that the lower the current you use, the better it is for the battery, but the battery won't die if you run it with higher current. In the worst case, you'd exceed the rating of the BMS, which would be something like 20 or 25amps, then it would self-protect and cut out. I think in OP's case he wouldn't care if his battery life is reduced from 3 years to 2 years and 10 months for the sake of a bit of extra power. That's his decision.
 
  • Like
Reactions: Hux

Woosh

Trade Member
May 19, 2012
12,025
9,198
Southend on Sea
wooshbikes.co.uk
Controllers don't have loop wire shunt for many years. They are all SMD now.
When did you see one of them last time?
 

Woosh

Trade Member
May 19, 2012
12,025
9,198
Southend on Sea
wooshbikes.co.uk
In the worst case, you'd exceed the rating of the BMS, which would be something like 20 or 25amps, then it would self-protect and cut out. I think in OP's case he wouldn't care if his battery life is reduced from 3 years to 2 years and 10 months for the sake of a bit of extra power. That's his decision.
batteries often die of accidental deaths. It's the law of small probabilities. He'd be lucky to get away with just a blown fuse but more often than not, a blown fuse will end up as a dead battery.
 

Related Articles

Advertisers