JBS 4s BMS: JMS = Jaibaida?

Surferdudemi

Solar Enthusiast
I bought a 4s BMS from the JiaBaida0168 Store on AliExpress and it just arrived. What I got is not quite what is pictured, so now I'm not sure if this is a knock-off or maybe a newer model? What's pictured is JBD model SP04S020 and what I received is a JaiBaida SP04S020A4S. The connector layout across the bottom is slightly different and has labels that are not shown in the picture in the store. There are also three black and three blue wires attached, rather than two. Thoughts?
 

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pierre

Somewhere down South
You should be o.k. Quite a few companies manufacture this BMS now. The one with the 3 x wires is rated for 120 amps. The 2 x wire one is rated at 100 amps. The 120A version has 2 x external temp sensors (NTC) and possibly one on the board somewhere. My original 100A version came with only 1 x external NTC and one on the board somewhere. Just follow the connection diagram and you should be good.
 

Dzl

Perpetual Newbie & Unofficial Forum Librarian
Staff member
Moderator
When I originally did the research, my best guess, with moderate confidence was that JBD and Jaibaida were/are the same company. There are tons of different models/sub-models though
 

Yurtdweller

Solar Enthusiast
When I originally did the research, my best guess, with moderate confidence was that JBD and Jaibaida were/are the same company. There are tons of different models/sub-models though
I am also fairly certain that JBD=Overkill. I found a photo of their BMS with the exact same model numbers except for the 'A4S' portion, and a detailed overkill user manual written by a native English speaker. I am hoping that it all applies to my bms, because it confirms that their BMS can work in either series or parallel. I haven't yet found a user manual specifically for my model number. I am planning to parallel two 12v packs(or more) and possibly series up to 24v if necessary.
 

Horsefly

Photon Sorcerer
Overkill is definitely JBD, and JBD is Jiabaida (correct spelling, vs Jaibaida). I've purchased from both Overkill and directly from Jiabaida.

Overkill Solar does some value added to the JBD purchased on Alibaba or Aliexpress, such as putting in larger leads on the B- and C- pads, and I believe they do some calibration of the boards. However, the two best things about Overkill is that it is a U.S. based support if you need it, and the excellent manual that Steve @ Overkill wrote. Most everything in the manual applies to all the JBD models.
 

Dzl

Perpetual Newbie & Unofficial Forum Librarian
Staff member
Moderator
I am also fairly certain that JBD=Overkill.
Overkill does not equal JBD (as in they are not the same company), but the BMS's Overkill sells are JBD BMS's under their own brand name, which I think is probably what you mean.

They also put in the time/effort/money to write a manual for the specific models they sell. If you have the same model number, it should apply to you as well, if you have a different model number, it will still mostly apply, but some small and large things may be different (JBD has a lot of different models, and a few different lines I think).

Side note, Overkill Solar is a forum member, blanking on the name right now.

I found a photo of their BMS with the exact same model numbers except for the 'A4S'
With some careful study, I think you could probably learn to decipher the model numbers, from what I recall at least a good portion of the model number is pretty intuitive.
What is your model #?

I haven't yet found a user manual specifically for my model number.
Unfortunately there probably isn't one if its not one of the three Overkill sells.
believe the reason they wrote one is because there was no good documentation direct from the manufacturer. This is a great 'value add' from them, before that, I thought of them as just another reseller rebranding a ubiquitous BMS and selling to a western audience, but my opinion of them really changed when they took the time to write that up (or pay to have it done). Since then, I have come to see them as a reseller that adds considerable value to the community.
 

Horsefly

Photon Sorcerer
Thanks for the clarification. The BMS I received is marked Jiabaida SP04S020A4S 100 A.View attachment 73528
As an example of the value-added from Overkill, the wires on they one you got are probably 12AWG and probably pretty short. Overkill replaces them with longer and larger 8AWG. Like I said, I'm pretty sure they also calibrate the BMS. The one I got was pretty well calibrated, but the ones I've gotten from JBD required some more calibration of the cell voltages.
 
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