Battery advice

soundwave

Esteemed Pedelecer
May 23, 2015
16,746
6,444
48V x 20A is hardly a 250W of continuous power. Or am I missing something?

Derestriction, ‘off-road’ switches or modes and dongles

The Department of Transport say that electric bikes fitted with off-road switches or modes, that enable a bike’s motor to continue assisting to speeds beyond 15.5mph, do not comply with UK EAPC law. The term ‘off-road’ suggests that these bikes can be ridden on parkland, forests or other places away from main roads, which isn’t accurate. E-bikes with increased motor power (continuous rated power above 250w) or increased speed (with motor assistance not cutting out at 15.5mph) cannot be used legally as bicycles anywhere on land accessible by the public; when riding on private land you would need permission from the landowner.

any bike with a open controller that you can change power and speed settings is not road legal.

why do you think i use a dongle because there is no other way to remove the speed limit.

but this part of the law has never been enforced and the only brands that did make kits or bikes with locked down controllers have gone bust.

seen a guy yesterday on a new haibike and knew he had a dongle fitted and got the yamaha motor because did not want any bosch anti tamper crap and it going in to limp mode lol.

wait untill they use gps to track ur ass 247 no dongles will work then ai says no bike shut down :p
 

saneagle

Esteemed Pedelecer
Oct 10, 2010
6,563
3,056
Telford
48V x 20A is hardly a 250W of continuous power. Or am I missing something?
Yes, you are missing something - the understanding of the regulation. There is no regulation on continuous power. It's on the rated power.
 

Sturmey

Esteemed Pedelecer
Jan 26, 2018
631
344
68
Ireland
Can anyone advise a good pre-made battery that will work well for my project?
One suggestion is to get two smaller batteries and wire each independently to the two controllers. You fit pedal assist with display on the rear motor and a basic throttle kit on the front motor with no pas and the display bypassed .(The front motor then works independently as a sort of throttle controlled booster motor).
PS Make sure front forks are suitable for motor.
 
Last edited:

esuark

Esteemed Pedelecer
Jul 23, 2019
266
195
kent
One suggestion is to get two smaller batteries and wire each independently to the two controllers. You fit pedal assist with display on the rear motor and a basic throttle kit on the front motor with no pas and the display bypassed .(The front motor then works independently as a sort of throttle controlled booster motor).
I think the OP has given up on two motors as in post #17
 

Woosh

Trade Member
May 19, 2012
20,214
16,818
Southend on Sea
wooshbikes.co.uk
If the intention is building a road legal bike, then the question is how much real or maximum power you are going to need to climb hills around where you live?
 

Sturmey

Esteemed Pedelecer
Jan 26, 2018
631
344
68
Ireland
I think the OP has given up on two motors as in post #17
He has already bought the two kits. If he buys the two batteries, he can try out by fitting both kits on the one bike as suggested. Its a flexible option in that he can leave the rear kit on the bike and remove the front kit and fit to a separate bike with suitable (preferably steel) front forks if he so wishes.
 
Last edited:
  • Informative
Reactions: esuark

Woosh

Trade Member
May 19, 2012
20,214
16,818
Southend on Sea
wooshbikes.co.uk
He should test first which motor suits him best, front or rear, then use the second kit on another bike.
 

Cavemann

Finding my (electric) wheels
Mar 22, 2022
17
6
As with all best laid plans, mine didn't survive first contact.
My 2-wheel hub motor drive, twist throttle off-road project has turned into a single rear-wheel drive on-road project.
Currently it's working well with the twist throttle and I've posted another thread for advice with PAS.
53295
Once I get the PAS working I intend to remove the twist throttle.
It currently max's out at 22MPH, so my next task will be to figure out how to restrict it to 15.5MPH...
 

Peter.Bridge

Esteemed Pedelecer
Apr 19, 2023
1,204
539
As with all best laid plans, mine didn't survive first contact.
My 2-wheel hub motor drive, twist throttle off-road project has turned into a single rear-wheel drive on-road project.
Currently it's working well with the twist throttle and I've posted another thread for advice with PAS.
View attachment 53295
Once I get the PAS working I intend to remove the twist throttle.
It currently max's out at 22MPH, so my next task will be to figure out how to restrict it to 15.5MPH...
Looks great ! - on my display / controller it's press and hold the + and - buttons together to set the max assist speed. I'd not thought of putting the controller under the downtube - does it need any weather protection for the controller and connections ? (bag?). What hub motor is it ?
 

Cavemann

Finding my (electric) wheels
Mar 22, 2022
17
6
Looks great ! - on my display / controller it's press and hold the + and - buttons together to set the max assist speed. I'd not thought of putting the controller under the downtube - does it need any weather protection for the controller and connections ? (bag?). What hub motor is it ?
Hi @Peter.Bridge,
Thanks, I'll try that out on my display.
I'm not 100% sure on the weather protection, I've seen lots of people buy a box to put the controller in. My thinking is that the two end plates have rubber gaskets, so in principle are water-proof. That leaves the cable entry point which has a rubber grommet but looks a bit baggy around the cables, so I positioned the controller facing down and to the rear, so shouldn't suffer from spray off the front wheel and water from above should flow down the cables and not inside the box. Time will tell I guess...
I'm using a Bafang RM G020.250.DC motor
 
  • Like
Reactions: Peter.Bridge

saneagle

Esteemed Pedelecer
Oct 10, 2010
6,563
3,056
Telford
Hi @Peter.Bridge,
Thanks, I'll try that out on my display.
I'm not 100% sure on the weather protection, I've seen lots of people buy a box to put the controller in. My thinking is that the two end plates have rubber gaskets, so in principle are water-proof. That leaves the cable entry point which has a rubber grommet but looks a bit baggy around the cables, so I positioned the controller facing down and to the rear, so shouldn't suffer from spray off the front wheel and water from above should flow down the cables and not inside the box. Time will tell I guess...
I'm using a Bafang RM G020.250.DC motor
It's quite important to make sure that the top end is sealed, and better to leave a drain hole at the bottom in case it isn't. If you're worried about water getting in the drain hole, put a bit of thin plastic tube in the hole.
 
  • Like
Reactions: Cavemann

Peter.Bridge

Esteemed Pedelecer
Apr 19, 2023
1,204
539
Hi @Peter.Bridge,
Thanks, I'll try that out on my display.
I'm not 100% sure on the weather protection, I've seen lots of people buy a box to put the controller in. My thinking is that the two end plates have rubber gaskets, so in principle are water-proof. That leaves the cable entry point which has a rubber grommet but looks a bit baggy around the cables, so I positioned the controller facing down and to the rear, so shouldn't suffer from spray off the front wheel and water from above should flow down the cables and not inside the box. Time will tell I guess...
I'm using a Bafang RM G020.250.DC motor
I have 2 menus on my display one is hold + and- buttons and one is hold + and - buttons and repeatably press power (8 times?), think the max assist speed is on the first menu (use + and - to adjust and power button to toggle through options. I'm wondering if it is already set to 35km/h, I would expect that motor with a full 48v battery to have a higher unrestricted PAS top speed, unless it is a really high winding.
 
Last edited:
  • Like
Reactions: Cavemann

saneagle

Esteemed Pedelecer
Oct 10, 2010
6,563
3,056
Telford
I have 2 menus on my display one is hold + and- buttons and one is hold + and - buttons and repeatably press power (8 times?), think the max assist is on the first menu (use + and - to adjust and power button to toggle through options. I'm wondering if it is already set to 35km/h, I would expect that motor with a full 48v battery to have a higher unrestricted PAS top speed, unless it is a really high winding.
That's like the Freego ones. I'm not sure about yours, but some have two speed limits: One for the throttle and the other for the pedal assist.
 
  • Like
Reactions: Cavemann