Hi Power BBS02 confusion!

[roshan]

Hi guys, I was going through HPC's mid motor offerings here: http://www.hi-powercycles.com/hpc-mid-drive-conversion-system-custom-bafang-8fun-bbs02/

If you select the 1400W motor, it says:
"Most retaillers will have anywhere from 21A-25A depending on where you source it. Our kits come standard with a custom 6061 Aluminum Adapter that allows for our included 32-38T sprocket vs the standard 46 or 48T. Compared to stock, the narrow wide chainring provides more consistant chain retention and allows the motor to be geared down for higher torque and efficiency. "

Later they say: "All 36V motors will have the same "500W" stamp on the bottom as other 8Fun Mid Drive Motors. All 48V+ motors will have the "750W" stamp on the bottom. We feel these numbers are very misleading and by no means is any 750W BBS02 fully street legal as even the least powerful versions we have tested from other vendors still put out over 1000W. It is a game that the manufacturer plays to try to be "legal" in certain countries when in fact they are not! This is why we always provide actual system outputs both electrically and mechanically with output to the rear tire where it matters! Don't be mislead into thinking our 1400W kit is almost twice as powerful as another 750W BBS02- It is not. It is anywhere from 50-250W higher on average for the same battery for "750W" stamped motors. Compared to a true 25A output controller (stamped 48V x 25A), we see on average about 50-60W higher power output. In rare cases, we have seen over spec 25A controllers from other vendors that have even slightly exceeded our 26A controllers."


So are they just custom programming their bbs02 or are they getting a custom controller installed from factory? I'm confused!

 

[nukgat]

I don't know what kit or programming HPC sells, but my bafang BBS02 750W kit maxes out at 26A at 48V. I get my readings via cycle analyst.

 

[roshan]

I don't know what kit or programming HPC sells, but my bafang BBS02 750W kit maxes out at 26A at 48V. I get my readings via cycle analyst.

That's stock 750W. Mine do too.

 

[neptronix]

Eh, my BBS02 from em3ev was peaking out at something like 30A. There is nothing special about what HPC is selling. They just programmed it hot like em3ev has.

 

[BigEzy]

So are they just custom programming their bbs02 or are they getting a custom controller installed from factory? I'm confused!

roshan,
I was told yes, on modified controller by HPC. Controller arrives different from factory and also modified by HPC "Programing"

I just installed their 1200w mid-drive system. When I placed my order I asked the same question, and was told by Chris & George;

The kit is based on a 48v, 750w, BBS02.
It has a 26A factory modified controller with modified programming.
It comes with a reduced 38T sprocket.
The Battery is a 12.5Ah, 52v. It charges to 58.8v.

According to HPC, these changes account for the increased torque, range, and efficiency. And yes, the battery cost more than the motor kit.

This being my first build, I am a noob on ebikes, but felt I knew enough from researching ebikes here, and other project applications experiences. It should make sense that these type modifications could be done easy enough by a supplier and should make a marked improvement over a "stock" BBS02 with a 48v battery.

So far, my kit is performing as good or better than expected, but I do not have any other Ebike experiences to compare it to.

http://endless-sphere.com/forums/viewtopic.php?f=28&t=66682

 

[r3volved]

12.5ah? Are you pulling more than 25a?
Is that a 3c battery? Is it meant to go with that kit in particular?

 

[roshan]

Eh, my BBS02 from em3ev was peaking out at something like 30A. There is nothing special about what HPC is selling. They just programmed it hot like em3ev has.

That was exactly what i suspected.

 

[BigEzy]

12.5ah? Are you pulling more than 25a?
Is that a 3c battery? Is it meant to go with that kit in particular?

According to my CA, I have pull over 30A several times on a slow steep climb, but normal range seems to be about 15-20a when accelerating with full power while already moving.

As I say, I am very new to this, so I do not know much about the battery. And unfortunately HPC did not provide ANY documentation. This is the description they have. " All New Li-NMC (Nickel Manganese Cobalt) packs provide more power lighter weight smaller and 25% more range than last year's LiFePo4 chemistry! -Lightweight High Quality 51.8v (nominal) Li-NMC 14S battery pack with integrated full featured high performance Battery Management System for improved performance and drain rates up to 60A continuous!"

According to my CA. I have used over 10Ah of the rated 12.5Ah several times, with remaining voltage around 50v. The two times I did run the battery till cut-off, I had not yet installed the CA. Battery takes about 2.5hrs to fully charge with 58.8V, 6A. charger.

Yes, battery comes with kit, with several options on Ah & cell quality. But both motor kit and battery are also available separately.

Eh, my BBS02 from em3ev was peaking out at something like 30A. There is nothing special about what HPC is selling. They just programmed it hot like em3ev has.

This is what I gathered as well.. Some minor tweaks and a quality (or at least I hope) battery. Not unlike what other recommended vendors sell.

 

[neptronix]

Yup. I could run 14S as well and have 1600W peak from my em3ev kit if i wanted.

But this is one thing to keep in mind: the drive cannot handle that power continuously.. not even close . It will very quickly saturate the stator and then go into power limiting due to the temp sensor inside. It does this by design at stock power levels. You have 1600w for a few minutes, then you get dialed down to.. who knows.. 750w continuous?
The HPC kit will have the same stator and thermal limitations.

By the way, 14S will give you a very high pedaling cadence which isn't comfortable to pedal at for a long period of time. That's fine if you wish to not pedal at all. 13S is really the sweet spot for this drive, for pedaling.

 

[BigEzy]

By the way, 14S will give you a very high pedaling cadence which isn't comfortable to pedal at for a long period of time. That's fine if you wish to not pedal at all. 13S is really the sweet spot for this drive, for pedaling.

Interesting. I have that exact same problem, I feel It's a little to fast, I tried to count it the other day and it seemed about 60rpm cadence. Maybe 45 would be better for me? I was thinking the reduced 38t sprocket was the cause? I did not realize battery discharge rate played a major role in cadence?

 

[neptronix]

It's all about the battery voltage. That determines the speed of the motor output.
38t is also a rather short gearing, which does prevent the drive from spinning at speeds which if continuously held, would overheat it pretty badly.

It probably spins at something like 90-100rpm on 14S.

 

[samsavvas]

So are they just custom programming their bbs02 or are they getting a custom controller installed from factory? I'm confused!

AFAIK all 48V BBS02 motors and controllers are the same - same windings, same controller etc. I very much doubt that a single vendor in a relatively small market like the USA would be able to get Bafang to build something new and different for them alone! Their supplied battery might have more cells and a higher voltage or current, but as others have said, in a geared mid-drive, increased voltage, current and top-end motor speed has implications for both motor/controller longevity and riding comfort. Messing with the controller's settings is also a fraught exercise - you need to know what you are dealing with! And if you put a tiny chain wheel on the drive shaft of course you are going to get more torque at any one particular speed. But it won't give you more 'power' per se!

My feeling is that the BBSxx drives work well within a relatively narrow band of parameters. They are mainly designed for every-day transport and commuting. I don't believe they are built for extremes or for hotting up. For sure you can go down that route but it seems you will rapidly cross over into compromised performance and longevity. I think Bafang's designers got it more or less right first thing. Changes we've seen since these drives first came out have just been incremental increases in quality and safety margins. I would be quite skeptical of vendors who reckon they can super-charge what is a clever but relatively modestly designed unit.

Savvas.

 

[amigafan2003]

You can slow the cadence down with programming.

Mine's set to about 70rpm which is ideal for me and it runs on 15s but only charged to 62v (it trips the HVC is the voltage is above 62.25v).

 

[opperpanter]

Looks like HPC BBS is nothing special. Just put in some better matching sprocket for off road driving and some programming that you could do yourselve.

 

[neptronix]

I didn't know you can do that.... but that's not ideal. Basically, the controller goes into heavy PWM to limit the speed. It's just like how a 3 speed switch works on a hub motor.

Do keep in mind that you're sacrificing some efficiency and making the controller work harder when you do this. It seems like you're also negating some torque that would have been gained by going to a higher voltage too, but i'm not familiar with the intricacies of how the bbs02 controller works so i can't say..

You can slow the cadence down with programming.

Mine's set to about 70rpm which is ideal for me and it runs on 15s but only charged to 62v (it trips the HVC is the voltage is above 62.25v).