36v battery with 48v motor

Hi all, First post. I have a bbs-01 kit with a 36v battery and I want to change to a front hub 250w motor. If I get a 48v motor can I use it with a 36v battery if the controller can do 36v too? Would this harm the motor or make the battery go on fire? Not understanding this at all, the conflicting information across the internet just confuses me. Help!

 

Thanks

You can, but it will run at 36/48=3/4 of the claimed max speed (so if it runs at 240rpm at 48V it will only run at 180 rpm at 36V) Why not get a 36v front hub motor ?

Edited July 24, 20241 yr by Peter.Bridge

Motor will run slow and with less torque. Battery will be OK so long as the maximum current is no greater than it is now. However I suspect this will lead to the motor feeling underpowered.

Why a 48v motor? If you get a 36v motor and wish to change to 48v battery and control later, the motor will handle this no problem.

Hi all, First post. I have a bbs-01 kit with a 36v battery and I want to change to a front hub 250w motor. If I get a 48v motor can I use it with a 36v battery if the controller can do 36v too? Would this harm the motor or make the battery go on fire? Not understanding this at all, the conflicting information across the internet just confuses me. Help!

 

Thanks

Hub-motors don't really care about voltage. The voltage only affects their max speed in direct proportion. If you need more power, you can always increase the current, as long as your battery can provide that current.

I don’t really understand the advantages of a 48v over a 36v motor. Are 48v motors not more robust and longer lasting? What I would like is long range ability, maybe 40 or 50 miles and low front hub weight. Does range depend on voltage or battery capacity?

I don’t really understand the advantages of a 48v over a 36v motor. Are 48v motors not more robust and longer lasting? What I would like is long range ability, maybe 40 or 50 miles and low front hub weight. Does range depend on voltage or battery capacity?

 

An advantage of a mid-drive compared to a hub drive is that it makes use of your bike's gears

 

GOOGLE hub motor v mid drive

 

https://www.electricbikesales.co.uk/blog/hub-drive-v-mid-drive-which-electric-bike-motor-is-best/#:~:text=Mid%2Ddrive%20ebikes%20also%20tend,use%20of%20your%20bike's%20gears.

An advantage of a mid-drive compared to a hub drive is that it makes use of your bike's gears

 

GOOGLE hub motor v mid drive

 

https://www.electricbikesales.co.uk/blog/hub-drive-v-mid-drive-which-electric-bike-motor-is-best/#:~:text=Mid%2Ddrive%20ebikes%20also%20tend,use%20of%20your%20bike's%20gears.

And the weight is in the middle on the bike but I want to change to a front hub.

I don’t really understand the advantages of a 48v over a 36v motor. Are 48v motors not more robust and longer lasting? What I would like is long range ability, maybe 40 or 50 miles and low front hub weight. Does range depend on voltage or battery capacity?

They're the same, so there is no advantage. The advantage comes when you run whatever motor at 48v. At the same current, you get 30% more torque from 48v, or you can use 30% less current toget the same torque as running at 36v.

 

Let's say that you have a 36v 260 rpm motor and a 48v 328 rpm one of the same type. At 36v, they will both give identical performance - x amount of torque and 260 rpm max speed. At 48v, they both give 1.3x torque and 328 rpm.

 

Let's say that you have two batteries. One is 48v 12 ah 13S4p (52 cells) and the other is 36v 15ah 10S5P (50 cells). Whichever battery you use, both motors will give approximately the same range as each other. To be precise, the 52 cell one will give 4% more range because it has 2 extra cells. On a ride at full power all the time with a 15 amp controller, either motor with the 48v battery will give 30% less range than the 36v one because you’ll be using more power and getting more speed, assuming no limit set.

 

In the real world, you ride with the amount of power you want. 48v gives the potential for 30% more torque/power, but most of the time you don't use the extra power, so not much effect on range, but if you have a lot of hills and turn up the power to max, then range would be affected more. Range depends on how many watt-hours in the battery when you start and how fast you use them up. 48v has the potential to use them up faster, but how fast you use them depends on you.

I don’t really understand the advantages of a 48v over a 36v motor. Are 48v motors not more robust and longer lasting?

No

 

What I would like is long range ability, maybe 40 or 50 miles and low front hub weight.

 

Maybe an AKM75 or Bafang G62 - what is your weight, fitness, what terrain are you likely to use the bike for ?

 

Does range depend on voltage or battery capacity?

 

A 48V 10Ah battery would have approximately the same range and weight (and possibly the same number of cells) as a 36V 13.5Ah battery

An advantage of a mid-drive compared to a hub drive is that it makes use of your bike's gears

 

GOOGLE hub motor v mid drive

 

https://www.electricbikesales.co.uk/blog/hub-drive-v-mid-drive-which-electric-bike-motor-is-best/#:~:text=Mid%2Ddrive%20ebikes%20also%20tend,use%20of%20your%20bike's%20gears.

You have to feel sorry for the guy. He has no experience of what's available, so he just bleats his diluded mantra. One day he'll try a decent hub-motor system. It' going to be tragic when he realises the mistake he's been making all this time. He'll be inconsolable, poor guy.

Maybe an AKM75 or Bafang G62 - what is your weight, fitness, what terrain are you likely to use the bike for ?

11 stone, slightly overweight, slightly fit

Mostly paths and off-road but no technical MTB stuff. Some on road but I try to avoid traffic.

11 stone, slightly overweight, slightly fit

Mostly paths and off-road but no technical MTB stuff. Some on road but I try to avoid traffic.

Front hub-motors are nowhere near as good as a rear one. Why wre you considering one? What bike are you wanting to convert?

Front hub-motors are nowhere near as good as a rear one. Why wre you considering one? What bike are you wanting to convert?

Simplicity and cheapness? Bike is a 30+ year old Specialized. Only want a motor to help me out when I’m knackered.

Likely a stupid question, why are rear motors better than front?

Likely a stupid question, why are rear motors better than front?

Safer, easier to install, better steering, better traction and better suspension. You should only fit a front motor if there's no choice, like when you have hub gears.

 

Does your bike have disc brakes? If not, it's probably a good idea to buy a donor that has them before doing all the installation work.

I have cantilever brakes and they are working well, no issues over the months I used the BBS-01 mid set up. Also I have no suspension. I was a little concerned about the torque effects on front forks. Any recommendations for a 250w rear kit?

I have cantilever brakes and they are working well, no issues over the months I used the BBS-01 mid set up. Also I have no suspension. I was a little concerned about the torque effects on front forks. Any recommendations for a 250w rear kit?

 

Did your BBS01 wear out or fail? Why are you getting rid of it? Just curious. I have one and like it a lot for my hilly location.

Maybe this?

https://www.ebay.co.uk/itm/393411923286?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=af9qsealrbi&sssrc=4429486&ssuid=luwi6nqksbk&var=&widget_ver=artemis&media=COPY

Did your BBS01 wear out or fail? Why are you getting rid of it? Just curious. I have one and like it a lot for my hilly location.

 

No the BBS-01 is fine, could be a long walk if the chain breaks though and I don’t really like the way the mounting plate cuts into the bottom bracket. And I like the look of a compact hub motor. The mid drive was just the first type I tried now I want to try a hub:cool:

Maybe this?

https://www.ebay.co.uk/itm/393411923286?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=af9qsealrbi&sssrc=4429486&ssuid=luwi6nqksbk&var=&widget_ver=artemis&media=COPY

its just a bit of a cheapo controller - try to find one with a KT controller - they have power based PAS levels rather than speed based PAS levels

I'm a fan of front hubs albeit small light ones that don't affect steering via weight ot torque steering.

At 11st one is perfect for one and 1.75st lighter then me and I love my small front hub.

The only advice I can give with front hubs is to always fit them into steel forks , my fork of choice is a Surly disc trucker fork.

No the BBS-01 is fine, could be a long walk if the chain breaks though and I don’t really like the way the mounting plate cuts into the bottom bracket. And I like the look of a compact hub motor. The mid drive was just the first type I tried now I want to try a hub:cool:

OK - fine and dandy.

 

I carry a small chain breaker and a quick link. If the chain breaks, I'd only need to remove one pin and fit the quick link to the two ends.

 

I think that given the small power of a 250 watt Bafang, the likelihood of a chain snapping is pretty small. In my whole cycling and motor cycling life, I have only once broken a chain and that was fifty years ago on a 650cc A10 side car outfit when I had put the back wheel on misaligned so the sprockets were sawing the inside of the chain plates. That chain was completely chewed all the way along and one plate broke and it snapped.

 

I was riding with very strong cyclist once, who snapped a bicycle chain. We were able to fix it so he could get back to base.

Maybe this?

https://www.ebay.co.uk/itm/393411923286?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=af9qsealrbi&sssrc=4429486&ssuid=luwi6nqksbk&var=&widget_ver=artemis&media=COPY

That's a freewheel motor, so OK for gears up to 7-speed. If you have 8 or more, you need a cassette motor.

 

When you choose a hub-motor, you have to get one that meets your needs, not just any one that's cheap, though it can be that a cheap one meets your needs perfectly. How fast do you want to go? What sort of hills do you have?

Going up in voltage is no problem, although your low speed biking may be faster than you want. Usually happens with 3 speed controllers, which are set too high in PAS 1 at 36V.

 

I own bikes with motors front/rear and in the middle, I prefer the mid motors for a faster install. No PAS sensor and controller box, Less work for a flat tire too,

 

I don't care for the niggling concerns about a front fork failure with my front motor bikes. As an engineer, I should trust my work though.

 

In the end, it's the bike, not where the motor is located. Give me a light sporty bike that runs good w/o a motor, and it's better for this old man with any motor.

 

 

 

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