Bafang 250W amazing range

[legin]

I have just completed a 30.5 mile ride using assist 5 out of 9 and the battery has only dropped one bar, I just checked the voltage and there’s 37v left, I did a test ride to work and back as this is the first real ride I have used it but I was surprised after getting back from work ( 11 miles each way) and the battery was still reading full, this is with a new 36v 21ah battery from Jimmy with all copper connectors but I wasn’t expecting that sort of range, I was using the throttle quite a bit too on the hills and long straights, had 31mph out of it on the straight....(standard bafang 46t ring)
It’s a 36v 250w bafang still at 15amps using Karl’s special sauce settings...I am really chuffed with how it has performed and won’t even charge it tonight so I can see what sort of mileage I will get from a full battery.......
Over the moon.........
Rob.

I have a 36v 417wh battery, with rear hub motor The bike weighs 22 kilos and I weigh 64. The claimed range on the flat with presumably no wind resistance is 60miles. This must be in Eco mode. Where I live in Devon is horrendously hilly, however, and the battery will drop 10% at full power on a climb at 1 in 5/6/7 of just over 300feet, so 40 wh. On a slightly less hilly route, I managed 16 miles and used 25% battery, so in keeping with what the makers boast. I have also managed, with 2 climbs of 300+ feet from sea level, including some other shorter, less steep, climbs, 20k ( the display shows only metric) with a 21% battery drain. The secret is to remain in Eco mode for as long as possible and to try moderately steep hills in what is called "City" mode, one up from Eco. Of course the one in 5/6/7 gradients have to be at full power. Switching off on the flat or downhill was also needed. But the main thing, and I have had the bike for 3 years, is to pretend you are on an ordinary bike, feathering the pedals as much as you can. So you are not necessarily going very quickly. I know this is not necessarily what an e-bike is about, but we are talking only about maximum battery range here. As we probably all know, the power required to get up steep hills does not equate to the power saved going down a similar hill and does not equate either to travelling on the flat. So, on very hilly ride, I would be lucky to get between 25-30 miles out of the battery, but with careful management, even with some moderately steep hills included,it should be possible to get considerably more than this.
One question I have, though, and it may have been answered above, is should I be riding in the lowest gear possible and at the highest cadence comfortable in order to get the lowest battery consumption?

 

[DeanosBeano]

Damn i am missing out , i get 16 miles on the forest Fire roads in Bowland with my 36 volt 200 watt 11Ah and 14 ah on my fatbike rear hub set up . i think ill give this Mid Drive lark a coat of looking at i swap my batteries out (carried in paniers) when they are at 32 volts

 

[vfr400]

Damn i am missing out , i get 16 miles on the forest Fire roads in Bowland with my 36 volt 200 watt 11Ah and 14 ah on my fatbike rear hub set up . i think ill give this Mid Drive lark a coat of looking at

You might end up disappointed. Energy cannot be conjoured up from nothing. Read the whole thread before deciding.

 

[Nealh]

I have just completed a 30.5 mile ride using assist 5 out of 9 and the battery has only dropped one bar, I just checked the voltage and there’s 37v left, I did a test ride to work and back as this is the first real ride I have used it but I was surprised after getting back from work ( 11 miles each way) and the battery was still reading full, this is with a new 36v 21ah battery from Jimmy with all copper connectors but I wasn’t expecting that sort of range, I was using the throttle quite a bit too on the hills and long straights, had 31mph out of it on the straight....(standard bafang 46t ring)
It’s a 36v 250w bafang still at 15amps using Karl’s special sauce settings...I am really chuffed with how it has performed and won’t even charge it tonight so I can see what sort of mileage I will get from a full battery.......
Over the moon.........
Rob.

37v is about 50 - 60% capacity so the one bar dropped isn't a true reading, the final bars should appear a lot quicker then you think.

 

[dwvl]

One question I have, though, and it may have been answered above, is should I be riding in the lowest gear possible and at the highest cadence comfortable in order to get the lowest battery consumption?

If yours is a hub motor, it will be unaffected by what gear you choose - it's connected directly to the wheel, after any gears. The gears are for your legs, so you should choose whatever gear is most comfortable for you at any given point in your journey.

Of course, the battery consumption of any motor is determined by how hard you work it. If you let the motor do all the work without putting in much pedal effort yourself, the motor will take that energy from the battery. If you put in more of the work yourself, the motor will take less energy from the battery. This is obviously true for hub and mid-drive motors alike.

 

[DeanosBeano]

My fat bike is currently offline so I went and wired up it's batteries to my Juicy bike and went to the forest today that's 3 36 volt batteries swapped when down to 1 bar
10,11 and 14 AH on a 250 watt motor
Mainly fire roads and 4 steep climbs I got around 16 miles with about 8 left in battery

The contraption made out of necessity to get to the forest

 

[anotherkiwi]

If yours is a hub motor, it will be unaffected by what gear you choose - it's connected directly to the wheel, after any gears. The gears are for your legs, so you should choose whatever gear is most comfortable for you at any given point in your journey.

The motor having to supply less Watts because you are pedalling in the correct gear won't be affected by the gear you have chosen? Do we have a new law of physics about to be published to an unsuspecting world?

 

[awol]

The contraption made out of necessity to get to the forest

Thats a strange seat angle, I think I would be sliding off it.

 

[DeanosBeano]

Thats a strange seat angle, I think I would be sliding off it.

Haha the gel is all at the top so I sit on that , although I'm stood most of the time in the forest .

 

[dwvl]

The motor having to supply less Watts because you are pedalling in the correct gear won't be affected by the gear you have chosen? Do we have a new law of physics about to be published to an unsuspecting world?

I'm not sure how I have confused you. Please read my post again (all of it, if it helps) and then I can clarify any bits you take issue with.

 

[anotherkiwi]

I'm not sure how I have confused you. Please read my post again (all of it, if it helps) and then I can clarify any bits you take issue with.

The motor, even a hub motor, is affected by the gear you are in. Unless you are riding a moped (throttle only).

Initially I was also under the impression that because the motor is in the hub gears didn't matter but they do. On the same stretch of road being in the correct gear can save up to 2 Wh/km from experience, possibly even more.

The physics are simple: you input a certain number of Watts by pedalling. If you are pedalling inefficiently (in the wrong gear) those Watts will be lost as heat...

 

[dwvl]

The motor, even a hub motor, is affected by the gear you are in. Unless you are riding a moped (throttle only).

Initially I was also under the impression that because the motor is in the hub gears didn't matter but they do. On the same stretch of road being in the correct gear can save up to 2 Wh/km from experience, possibly even more.

The physics are simple: you input a certain number of Watts by pedalling. If you are pedalling inefficiently (in the wrong gear) those Watts will be lost as heat...

I understand where you're coming from. I acknowledge of course that the more efficiently you pedal, the less work there is for the motor to do, so the less battery it uses. If you're pedalling in the wrong gear, you're going to find it difficult, the motor will end up working harder, using more battery and getting hotter. So we agree, I think.

I thought, though, that this thread is about the OP's (Jayfdee's) delight with the range he achieves using his mid-motored bike, and the assertion that it's because (through selecting the correct gear) the motor can be operated at its speed of peak efficiency whatever the bike's speed?

Then another poster (Legin) said he has a hub-motor, and asked whether he should also "be riding in the lowest gear possible and at the highest cadence comfortable" for best range. In reply, I tried to say that a hub motor's efficiency won't be affected by his cadence because choice of gear doesn't affect the speed at which the hub motor is running (at a given bike speed) - unlike a mid-mounted motor. Legin should choose whatever gear his legs work best at, because the gear chosen is for his benefit, not the hub motor's (and again, unlike a mid-mounted motor).

So, I didn't mean to invent "a new law of physics" and I'm sorry that you inferred that from my original reply. I will try to be more precise in the future.

 

[anotherkiwi]

I could have been gentler in my reply, I'll accept a yellow card and use "tough week at work" as an excuse.

I have both types of motor. I have trouble being efficient with the mid drive because I have a high natural cadence and spin fast enough to get back EMF. On the other hand the hub motor and I both spin at our peak efficiency up to the rated speed of the motor.