Bafang Ultra mid drive running on 52v?

roissy · Feb 29, 2020

Sorry if this has been brought up before, but after skimming the postings I did not find it...
I have an ebike ordered with a Bafang Ultra mid-drive, it is using the "dorado" type of downtube battery at 42v which seems to be more common these days.
I have found a rather interesting 52v replacement battery on Alibaba, would this be a plugin performance upgrade for the Bafang Ultra?

Thanks in advance.

BTW: Does anyone have a quick way to deal with the "C" ratings showing up battery specs?

motorm3ssie · Mar 1, 2020

The capacitors on the Bafang Ultra Controller are rated 63 Volts, so i do run mine on a 52 volt battery, wich has 58.8 volts when fully charged. Lets assume your controller settings are at 30 amps:

30a x 42v = 1260 watts
30a x 52v = 1560 watts

So yes, performance improves

I dont get your second question, maybe its because im german and my english not perfect...

roissy · Mar 1, 2020

Thanks for your reply,

In researching battery replacements there seems to be a difference in the BMC's used. So yes, I want something with a minimum of 30a output. But what I have found a lot of Chinese spec sheets are using what is called "C" rating, I had to look it up.
I think I understand the rating, but I just have not gotten my head around it because it seems I still have to convert to amps which is what I am used to working with.
Just for fun Google "c rating battery"

Joe King1 · Mar 1, 2020

Talk to David, he'll take care of you :thumb:
https://www.eco-ebike.com/collections/52v

roissy · Mar 1, 2020

Joe King1 said:
Talk to David, he'll take care of you :thumb:
https://www.eco-ebike.com/collections/52v

Thanks for the link, unfortunately, he does not have the Dorado style (on frame) which is becoming so common.

motorm3ssie · Mar 2, 2020

I know what a c-rating is, maybe you should google it

Its easy to convert to amps, just multipy Ah by c-rating. I dont know your dorado battery but if its mounted inside a frame i guess its about 12.000 mAh. If it is c-rated at 2.5:

12 Ah x 2.5 c-rate = 30 A

But if you want to pull 30 amps continously then you should buy something stonger like 40 or 50 amps max. And do not believe random chinese sellers, they often lie about the specs. For batteries you should rely on a thrusted source!

roissy · Mar 2, 2020

motorm3ssie said:
But if you want to pull 30 amps continously then you should buy something stonger like 40 or 50 amps max. And do not believe random chinese sellers, they often lie about the specs. For batteries you should rely on a thrusted source!

Thank you for your answer...
I Googled it, but your example was better...
Most of what I am looking at is 17.5 or even >20ah. The majority of BMC's seem to be 20a continuous although I found one at 35.
As stated in another thread, someone suggested retrofitting the stock BMC with a 40a unit. They did not post a link to the item in question, so I might have to endear more Alibaba hell to find it...

Simonten · Mar 3, 2020

Like Joe King said Dave at eco bike.He will sort you out. With 40a or 50a bms

roissy · Mar 7, 2020

Simonten said:
Like Joe King said Dave at eco bike.He will sort you out. With 40a or 50a bms

I would like to thank all of you who suggested contacting Dave at eco bike...
At the moment they do not carry them but he was willing to build one for me...
And because they most likely will be selling a Frey model that uses that type of battery, they soon will be stocking them.

Bafang Ultra mid drive running on 52v?

roissy

10 µW

motorm3ssie

100 µW

roissy

10 µW

Joe King1

100 mW

roissy

10 µW

motorm3ssie

100 µW

roissy

10 µW

Simonten

1 W

roissy

10 µW

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