Bafang Max Drive bikes

[Ultrafunkula]

No you still get sag because you have privileged distance over power, you want at least 30Qs if not HD2s with a 22 Amp controller and those motors. You only get 15 Ah for the same number of cells but 60 A or 80 A current on tap. What is the BMS Amp rating?

I have nuked a bottle battery with my GSM at 15 Amps! These motors draw max Amps differently than hub motors do - maybe they ramp up quicker? Maybe they sustain current draw over longer periods? In any case they eat weak batteries for lunch...

Bms rating that Jimmy fitted is 50amp, he said that the 17ah GA cell pack would supply 22a without issue, a spin up the road at full whack sagged within a minute , only for it to recover after a few minutes of rest. You have me worried that I could destroy this pack , I may have to turn the motor down a little, For a little un it sure is greedy , many thanks to D8ve for input as I'm a bit of a thickie when it comes to all the tech stuff. Maybe I should find time to study amps and ratings a little more, surprised that the small motor isn't making heat with the large amperage going in, your thoughts?

 

[anotherkiwi]

I did a little experiment with the GSM:

- 10 Ah LiPo 15C rating (150 Amps but over on ES they say 20-25% is more realistic) so say 30 Amps constant or 2 x the controller max of 15 Amps. The battery sags by about 1-1.5 V at full power
- 20 Ah LiPo 10 C rating so about 40 Amps constant, the sag is now 0.6 V over the same road
- the 10.4 Ah Li-Ion rated for 20 Amps now sags >5 V (initially about 3 V)

I am currently studying my options for a new Li-Ion battery which I will assemble with a DIY kit. 3P10S for space reasons so 36V 9 Ah with 3000 mAh cells and because they are on sale will probably get Sony Konion 30 Amp rating. That will give me 90 Amps so I should see sag equal to or less than the 10C LiPo battery. My second choice is the HG2 followed by the 30Q in third place.

Your motor comes with a 25 Amp controller, Bafang have been building motors for ages, they know what they are doing, you won't see it overheating. The 500 W BBS02 (also 25 Amp) has been run for long periods at full power with negligible heat by the Americans.

 

[Deleted member 4366]

Bms rating that Jimmy fitted is 50amp, he said that the 17ah GA cell pack would supply 22a without issue, a spin up the road at full whack sagged within a minute , only for it to recover after a few minutes of rest. You have me worried that I could destroy this pack , I may have to turn the motor down a little, For a little un it sure is greedy , many thanks to D8ve for input as I'm a bit of a thickie when it comes to all the tech stuff. Maybe I should find time to study amps and ratings a little more, surprised that the small motor isn't making heat with the large amperage going in, your thoughts?

Sag of a couple of volts or so is nothing to worry about. It's just a matter of physics. I tested my new 10S2P LGHG2 battery at 10 amps. It sagged about 2 volts and became warm by the end of the test. That's not enough to cause any concern.

 

[anotherkiwi]

Except when the LVC kicks in half way up the last hill before home...

 

[Johncon]

I reached out to a couple of suppliers in Alibaba who have the Max drive kit listed as 250-350w. One answered now that it’s the same motor, on the 250 the controllers give max 15A and the 350 version 18A.

Sounds about right as the BBS01 had he exakt same difference?

he offered me to buy a 350 controller and I asked for more details, pricing and so on.

As I only have the original batterie that came at 10ah I think I would need a bigger/better one to use a setting higher than 20A?

 

[anotherkiwi]

Better cells at least. A 5P10S battery composed of LG HE4 cells would be a good option.

 

[Ultrafunkula]

I reached out to a couple of suppliers in Alibaba who have the Max drive kit listed as 250-350w. One answered now that it’s the same motor, on the 250 the controllers give max 15A and the 350 version 18A.

Sounds about right as the BBS01 had he exakt same difference?

he offered me to buy a 350 controller and I asked for more details, pricing and so on.

As I only have the original battery that came at 10ah I think I would need a bigger/better one to use a setting higher than 20A?

It would be good to have supplier of the 25amp rated controller instead of Emax 20amp one , hope they come back with good price,
My original 10ah battery with I think the 29 Samsung pinkies was ok for light commuting and gentle jaunts but any serious use or motors unlocked potential soon showed its unsuitability , 15 miles of low speed following pedal powered cycle I still had 3/4 battery life left ,yet I could do 15 miles and see it with a 1/4 left and feeling very lack lustre at full tilt.
Yet to use my new battery to any length of distance and time as I have been to busy to use the bike after fitting it.

 

[Johncon]

Unfortunately he didn't have the controllers after all. He had only 500w ones. For the BBS i suppose.
I wonder if those things are kept tight in a specific chain of logistics and not open for everyone. Other ways we would have seen more spare parts.
I may be that specific vendor only gets/sell full kits only.

In the meantime...
The bike. Not the best parts but they'll do. Got it for 1100gbp and well se if I change the fork and brakes or Ill look for a FS emtb. Ebikes rock.


Did my first tour offtrack. Im just a novice in the woods but damn this thing climbed. I had to be carefull downhill on technical passages not to pedal as the bike would just take off!
Had lvl 4-5 for the most and lowest gear (38-11) and it climbed well. Off course i hade to help a bit but you could feel the motor pulling you up.

On the road the biked holds 30-36 km/h on flats depending on level 3-5 without pressing to much with the legs. I think this is where the motor comes to its rev limit as I could feel it just droping power if the cadence was too high.

My bike has now 20A Limit as it was stock, assist levels are 20,40,60,80.100.
Keep current at 50% and Current decay 4.
I think the battery hold ok too.
Pulled the trailer with our two kids for 15km
Speedrun 14km
Offtrack 5km
Had 6 bars left (of 10) on the meter. Seems ok for 35km of moderate to heavy work.
How accurate is that thing anyway, one should never get under 30 in order to not damage the cells?

 

[Johncon]

Washed the bike today, Only water with a hose to remove dust and the display was like this after. It was like that for 2-3h then it started to dry.
This is supposed to be waterproof so I wonder if you have experienced he same or should I try to get the lcd replaced?

 

[Ultrafunkula]

Nice looking bike, climbing ability on these motors are great, so silent too, I have my keep current at 80, makes motor a little louder ,my display I have never got wet but they are supposed to be watertight, Brightonebikes on this forum has fitted a colour display to the max drive , looks mighty nice too.

 

[Johncon]

Ah. I wasnt to glad about that so I took it to the dealer l and I ended up returning it.
Liked the motor but the bike itself was not on par. Seem I might get to the next level and that means a Bosch. Not many Max drive bikes here.

 

[Kinninvie]

Booked a test ride of a Freego Martin Sport for next Thursday.
Its for a 20 stone pal who wants to get some exercise while following my BBSHD..
I guess I will have to detune it to 500 watts so I dont lose him in the first 5 minutes.
Be interesting to see how the torque sensor feels compared to my BBS motors.
Hopefully I will like it as I really fancy the 1000 watt Max drive motor.

 

[Woosh]

A heavy guy will do well on a torque sensored system.
(unless he is asthmatic).

 

[Johncon]

Given i have returned the old bike with the max drive I thought I come and share some points comparing it to a Bosch CX. Maybe it is of interest for some.

-The Bosch has Only 4 modes/levels and even at the first(eco) you have enough power. Campared to the Max drive where 1 didn't do much.
The Bosch i also a little bit more powerfull, turbo is...turbo compared to the Bafang with stock settings.
(Compared after I tuned the max drive at 50% keep current and linear assist levels, I’d say they are similar Bosch is a bit stronger at the bottom)

-The pedalassist/torque sensor is quite similar in funktion between the two
-The Bosch is louder. Is noticeable too and not by a small margin. Bafan did well here
-It really sucks I have to buy a dongle for 130€ haha
-The bike I got, Cube Reaction, is a much better bike


I’m must say The Bafang is not a bad motor at all compared to the more expensive / sofisticated Bosch.

 

[AndrewJ]

D

Booked a test ride of a Freego Martin Sport for next Thursday.
Its for a 20 stone pal who wants to get some exercise while following my BBSHD..
I guess I will have to detune it to 500 watts so I dont lose him in the first 5 minutes.
Be interesting to see how the torque sensor feels compared to my BBS motors.
Hopefully I will like it as I really fancy the 1000 watt Max drive motor.

How did the Bafang Max compare with the BBS02 in terms of the power and the torque sensor?

 

[Kinninvie]

The Max was not too bad considering the lack of watts compared to a BBS02.
The torque sensor worked well although with my weak legs I prefer the speed control of the BBS02.
What really surprised me was the KTM Machina 273 that we also tried and ended up buying.
It climbed twice as easily as the Max drive and only cost £300 more.
Of course you can tune the Max drive quite a bit and maybe even get it to the same level but that would invalidate the warranty and as the bike was for a newby he didnt want to mess with it.
If I was buying for myself only I would have gone with the Max as I prefer to run LiPo batterys at £160 for 16Ah rather than the Bosch £700 for 11.6Ah!!!

 

[Woosh]

The torque sensor worked well although with my weak legs I prefer the speed control of the BBS02.

the 48V MaxDrive is definitely suited to 100kg+ with weak legs.
On level 5 assist, you merely rotate the cranks to climb.

 

[Deleted member 4366]

The Max was not too bad considering the lack of watts compared to a BBS02.
The torque sensor worked well although with my weak legs I prefer the speed control of the BBS02.
What really surprised me was the KTM Machina 273 that we also tried and ended up buying.
It climbed twice as easily as the Max drive and only cost £300 more.
Of course you can tune the Max drive quite a bit and maybe even get it to the same level but that would invalidate the warranty and as the bike was for a newby he didnt want to mess with it.
If I was buying for myself only I would have gone with the Max as I prefer to run LiPo batterys at £160 for 16Ah rather than the Bosch £700 for 11.6Ah!!!

Comparisons are tricky. The reason that the two bikes climbed differently can only be down to gearing. There could be a slight power difference because some of the Max-drives are set to 15 amps, but you can re-program them to 22 amps, which would be much more powerful than the KT, but you still need the correct gearing to get the best climbing for you. You can always climb steeper hills by lowering the gearing.

 

[PhilYerBoots]

I've noticed a 'clicking' or 'whirring' noise from the motor on my Greenway Cross to be getting worse recently and it even does it with the motor off and rear wheel lifted whilst turning the cranks.

I suspect at the very least I will need to remove and strip the motor down and re-grease as shown by @josephcornelius here:-

http://www.pedelecs.co.uk/forum/threads/greenway-cross-city.26736/page-13#post-388264

At worst possibly looking at replacing the whole motor maybe ?

Has anybody else on here had any similar issues with the max drive unit ?

Based on worse case scenario can somebody recommend a seller for a replacement motor unit. I'm struggling to find any UK based sellers but seen a few on Alibaba for about $460, presumably with customs duty to add to that.