BBS02 500w versus BBS01 350w

[eHomer]

There's still a serious danger that I'm going to buy one of these damn things

My standard battery packs are 36v 10ah lithium-ion, so would the continuous current draw of the BBS02 500w be too much for them ? (is it 15 amps ?)

Would the BBS01 350w be safer with those batteries, long-term ? (assuming that would be about 10 amps ?).

I've read so much about these motors but I'm still unsure of any physical difference between the 01 and the 02. Are they the same construction, eg bearings, shafts, casing etc.. ?

I do understand the reasoning about Hub drives being more casual for commuting, and the considerations about extra loading on the transmission, so it would be in addition to having a hub motor bike, rather than instead of.

 

[amigafan2003]

I thought the 500W versions were 48v? But yes, you'd be pushing it on that battery.

Certainly on the 48v500w BBS02's the motor and casing is larger and the whole unit about 1lb heavier as a result.

I've got a 48v500w unit on the way.

 

[Geebee]

The main diffference is a longer motor so more copper and magnet.
500w come in 36 v and 48 v, battery wise it depends on what the batteries continuous rating is, some people on ES have had battery issues on the BBS02.
The 250w is 15amp, 350w 18 amp, and the 750w 25amp, I don't know for the 500 but I think your estimate are low for peak amps.

If you are not going to worry about leagality you may as well buy the BBS02 and run it on PAS 2 which will give similar performance to the lower powered one and have more reserve for over heating.

 

[eHomer]

Thanks for the replies.

BMS show 36v and 48v availability for the BBS01 350w and for the BBS02 500w, but just 36v for the BBS01 250w.

If the 02 is a pound heavier and more meaty then running it knobbled at PAS 2 with my limited batteries sounds like a good option in case I ever upgrade them to LIPO, but then again. I'll be stuck with deciding either 36v or 48v now.

 

[Geebee]

Personally if you have 36 v packs I would go with that, keeps universal usage betweeen bikes/trikes

 

[eHomer]

Personally if you have 36 v packs I would go with that, keeps universal usage between bikes/trikes

I've made that a standard for myself so far Geebee, as they're so expensive and will eventually need replacing.

The ability to get 33% more power/speed from the same weight of motor without putting extra current through the windings or controller is appealing though.

I'm assuming the BBO drives are wound differently for 36 and 48 volts, so that the pedaling cadence is the same ?

 

[Geebee]

From what I can gather maybe not as there are reports of 110 rpm on 48v, the bb01 on 36v seems to be 80 rpm.

I have been reading eveything about them as I will most likely buy the 250w version down the track.

 

[eHomer]

From what I can gather maybe not as there are reports of 110 rpm on 48v, the bb01 on 36v seems to be 80 rpm.

I have been reading eveything about them as I will most likely buy the 250w version down the track.

110rpm for my chubby legs , that would clinch the 36 volt version for me !!

That really does surprise me though. Having read about how hub motors have their rpm set by the windings, rather than the ratio of the planetary gears, I'd have thought that all crank drives would have be designed for a standard pedaling cadence.

If you have to pedal 33% faster with the 48v versions, that's a definite deal breaker for me.

 

[Deleted member 4366]

I've read somewhere that the 48v are the same crank-speed as the 36v ones. I also now heard of about seven different versions of volts and amps, presumably as each large customer has different requirements for the legislation in their country. Add to that the various software versions, and the whole thing is now becoming very muddy.

 

[eHomer]

I've read somewhere that the 48v are the same crank-speed as the 36v ones.......

That would make a lot more sense.

As you say, the more info that comes out on these drives, the more confusing it gets.

 

[Geebee]

From ES re the BBS02
"In the french forum someone postet that the 48V Motor is doing 140rpm on the crank with no load. Lcrewse told me 110rpm when you use throttle and the cadence is not limited, so the 110rpm on the crank with full load should be realistic."
Plus comments about higher PAS settings exceeding comfortable cadence levels.

 

[eHomer]

From ES re the BBS02
"In the french forum someone postet that the 48V Motor is doing 140rpm on the crank with no load. Lcrewse told me 110rpm when you use throttle and the cadence is not limited, so the 110rpm on the crank with full load should be realistic."
Plus comments about higher PAS settings exceeding comfortable cadence levels.

I certainly wasn't doubting what you had read Geebee, just wondering if some of the sources were confusing the issue by maybe running a 36v winding at 48v, rather than a 48 at 48 (if there is a difference).

Like you said, I'm reading everything I can find on the subject, and trying to assimilate the real SP.

 

[Geebee]

Yeah it is getting confusing all right, Lcrewse is the seller of them in America so his info should be accurate.
The programming tool Lcrewse has sounds like it would be great as an end user as you can setup just about every factor, and maybe causing a lot of the confusion due to different programming by different sellers.
It sounds like the 36v and 48v BBS01 is a similar speed to each other from various posts.

 

[Savvas]

I'm pretty sure that it's been established on ES that both versions are wound for similar motor speeds (rpm per volt anyway). But I'm not quite understanding why pedaling cadence is at issue here anyway. There's a freewheel (two in fact) between pedal and motor to prevent any over-running and danger to the rider from spinning cranks. And if you are starting to spin too fast, would you not just go to a higher gear to slow your legs down and increase the load on the motor (and reduce it's revs)? I thought that was the whole point of the mid drive - to work through the gear train?

Savvas

 

[Deleted member 4366]

It has a big effect on the motor's efficiency. Ideally you want the motor to be at about 2/3 its maximum speed at your natural cadence, so for me that would be a max motor (crank) speed of 90 rpm. If it can spin faster, it's efficiency will reduce while pedalling, or yours will.

 

[Domm]

Interesting thread. Am I to understand that (now in 2016) you must pedal with one of these mid drives or it will just force your legs round? Sounds unpleasant!

 

[KeithMac]

I've been looking into the BBS02 (and HD), trying to work out best compromise.

The Intersat 14.5ah 48v battery looks a good match.

I've read time and again you should not load these motors up at low rpm, use the gears to keep the rpms up or you'll overheat it or fry the controller.

 

[Fordulike]

Interesting thread. Am I to understand that (now in 2016) you must pedal with one of these mid drives or it will just force your legs round? Sounds unpleasant!

Nope, the chainring assembly has a one way bearing in it, so it freewheels when the motor is spinning. You just ride it like a normal bike

 

[Fordulike]

I've been looking into the BBS02 (and HD), trying to work out best compromise.

The Intersat 14.5ah 48v battery looks a good match.

I've read time and again you should not load these motors up at low rpm, use the gears to keep the rpms up or you'll overheat it or fry the controller.

If that's one with Samsung 30Q cells, then yes, it's a perfect match for the BBS02.

I find the trick is to keeping the motor happy, is to find a few hills and ride up them using leg power alone. If you struggle using one particular gear, then the Bafang won't like it either. Try a lower gear.

The pedals only need to be turning to kick the motor in, so you can actually use a much lower gear and just go through the motion of pedaling. This will keep the motor spinning fast, although there will be zero assistance from your own legs. Hope you get what I mean.

 

[culy30]

If I can add my tuppence worth.............PAS is exactly that, you turn the pedals and motor kicks in, you have the same freewheel as a normal bike. ie you can coast downhill without pedalling. The BBS series of motors all have similar characteristics, they go up hills really well, but you need to understand a little bit of physics in order to get the best result. As Fordulike says, use your gears, if its a very steep hill (say 15%) use bottom gear and pedal comfortably, you can even "soft-pedal" ie just keep up with the motor, and remember that the motor likes to spin quite fast. If you were to select a big gear (say top gear ie smallest rear sprocket) and try to climb a steep hill, your motor will have to work really hard, it will draw the maximum current allowed by the controller, the motor will get hot, the battery will drain faster and you could burn out some of the electronics if you do this for a prolonged distance. Its the same as trying to drive your car up a steep hill in top gear by putting your foot to the floor. The message is, use the gears in the same way you would when riding a non-ebike. I recently rode some steep hills and beat all the semi-professional racing cyclists fastest times by a big margin. I used bottom gear (my 34t biggest sprocket) and PAS 7. I could have gone faster on the 30t cog using PAS 8 or 9.

I ride all kind of bikes, I love riding all of them. The difference an ebike makes (to me) is:-its like having the wind in your back the whole time and I can wear normal outdoor clothing. I recently rode over 50 miles (each way) for a lunch appointment. I just needed to comb my hair and wipe the flies off my teeth (I smile a lot when riding the ebike) before sitting down to lunch. I make around 2-3mph higher average speed on the ebike compared with my expensive sub 7 kilo racing bike. I would have needed oxygen a shower, a massage and a change of clothing before sitting down to lunch.......................you get a good low intensity work out on the ebike.......you can chat to fellow riders while cruising along at a brisk pace and you wont break into a sweat..........unless its 37 degrees outside like today! Get one, you'll love it!

oh and the battery, fully agree with Fordulike. 30Q cells are the way to go.