A potential battery solution for dirtbikes?

[Pete's moto]

Searching for all things to possibly build my own battery pack I came across this module.
Could this be a solution for those doing a dirtbike conversion? According to the specs 2 of these side by side can fit in a dirtbike frame with very little modifications.
Can they be connected in series and be sufficient to power a mid drive motor like a qs?

Edited link


https://www.alibaba.com/product-detail/Ev-Battery-44-4v-50ah-Ncm_1600353346658.html?spm=a2700.wholesale.0.0.395c886cRCZRHP

 

[amberwolf]

Your link only goes to teh main alibaba website; you'll need to link to the specific product (and specific version if there is more than one, which is common), for us to see it.


If you connect battery modules that have a BMS in them in series, the BMS must be designed to handle the total series voltage, or else it will be damaged during any event that shuts any of the BMS's off because it will then have more voltage across it than it can handle.

What you need for a conversion will depend on the amount of power you need. That will depend on what exactly you want the bike to do for you, under what conditions, and for how long you want to do it.

If you want it to hoon around on under adverse conditons, you may need quite a lot of power, which means you need quite a lot of motor/controller, and the battery must be able to handle this continuously for as long as you push it hard.

If you need it to run hard for a long time you'll need a big battery with lots of capacity.

 

[Pete's moto]

Alibaba.com AppEv Battery 44.4v 50ah Ncm Lithium Ion Battery Module 12s1p 3.7v Cells For Electric Vehicle
https://www.alibaba.com/product-detail/Ev-Battery-44-4v-50ah-Ncm_1600353346658.html?spm=a2700.wholesale.0.0.395c886cRCZRHP
Try now?

 

[john61ct]

https://app.alibaba.com/dynamiclink?touchId=1600353346658&type=product&schema=enalibaba%3A%2F%2Fdetail%3Fid%3D1600353346658%26ck%3Dshare_detail&ck=share_detail&shareScene=buyer

The link only brings me to the Play store to download the Ali app.

Use a web browser not the app.

Try to get the store link if can't get the specific product one

example https://tzxiya.en.alibaba.com

 

[Pete's moto]

I'll post it later from home pc.
Somehow doesn't do it getting the link from alibaba app

 

[Pete's moto]

I have edited my first post with the correct link.
I hope it works :thumb:

 

[j bjork]

You still havent specified what discharge rate you expect, but according to the spec they are 50Ah and max 3c discharge.
That would mean 150A max.
I would want a lot more on a dirtbike.
Internal resistance 6,25mohm or something like that. Good if it is one module, bad if it is a cell.

The module they show is 6s2p not 12s1p..

 

[Chalo]

You still havent specified what discharge rate you expect, but according to the spec they are 50Ah and max 3c discharge.
That would mean 150A max.
I would want a lot more on a dirtbike.

That's over 13kW at 88V nominal, so like 13 hp after efficiency losses. How much do you think is adequate?

 

[Pete's moto]

You still havent specified what discharge rate you expect, but according to the spec they are 50Ah and max 3c discharge.
That would mean 150A max.
I would want a lot more on a dirtbike.
Internal resistance 6,25mohm or something like that. Good if it is one module, bad if it is a cell.

The module they show is 6s2p not 12s1p..

Yes the module shown in video is a 6s2p but I've seen other videos of other listings of same physical size modules of 12S1P reading 44V.
Can 2 44v be used in series?
They seem to be the sane size as the vw modules used on your build bjork
I'm trying to power maybe a qs138 70h or open to other suggestions.

 

[Pete's moto]

https://fb.watch/a1SfFH3y4d/

Showing 44v read in this video

 

[amberwolf]

Can 2 44v be used in series?

You have to ask the manufacturer about their BMS specifications, specifically which FETs are used, because as I noted before, if the FETs in it are not rated at least as high as the full charge voltage of all packs in series total, then they can fail if one of the BMS shuts off for any reason (trying to protect the cells, etc).

When the FETs fail, they often fail shorted, so that means you then have no protection agianst overcharge or overdischarge because the FETs can't switch input or output off anymore.

If they fail open then your system just shuts down because there's no power.

 

[j bjork]

You still havent specified what discharge rate you expect, but according to the spec they are 50Ah and max 3c discharge.
That would mean 150A max.
I would want a lot more on a dirtbike.

That's over 13kW at 88V nominal, so like 13 hp after efficiency losses. How much do you think is adequate?

About double that. That is for short bursts though, maybe the cells can handle that?

You still havent specified what discharge rate you expect, but according to the spec they are 50Ah and max 3c discharge.
That would mean 150A max.
I would want a lot more on a dirtbike.
Internal resistance 6,25mohm or something like that. Good if it is one module, bad if it is a cell.

The module they show is 6s2p not 12s1p..

Yes the module shown in video is a 6s2p but I've seen other videos of other listings of same physical size modules of 12S1P reading 44V.
Can 2 44v be used in series?
They seem to be the sane size as the vw modules used on your build bjork
I'm trying to power maybe a qs138 70h or open to other suggestions.

Sure you can series 2 of them, it depends on what voltage your controller can take.

Can 2 44v be used in series?

You have to ask the manufacturer about their BMS specifications, specifically which FETs are used, because as I noted before, if the FETs in it are not rated at least as high as the full charge voltage of all packs in series total, then they can fail if one of the BMS shuts off for any reason (trying to protect the cells, etc).

When the FETs fail, they often fail shorted, so that means you then have no protection agianst overcharge or overdischarge because the FETs can't switch input or output off anymore.

If they fail open then your system just shuts down because there's no power.

I dont think there are any bms, more a communication and balance board. That should then be connected to a bms master.
At least that is how it is on the car modules I used, and this looks similar.

 

[Pete's moto]

I dont think there are any bms, more a communication and balance board. That should then be connected to a bms master.
At least that is how it is on the car modules I used, and this looks similar.
[/quote]

I will have to confirm with the supplier but i don't think there is an integrated BMS.
The dimensions are 110x150x355mm similar to the gte modules you used on the YZF. Can you please confirm. If the same, 2 of these should fit in a RMZ250 frame too.

 

[j bjork]

Yes, it seems to be the same size

 

[Pete's moto]

They confirmed there isn't an internal bms in these modules.
$659US shipped for 2. Is this a good option?
Thanks for any input