BMS Group Buy

Groupbuy? “The BMS
Basically to partner with @Louisvdw 's new BMS driver for Victron, etc

Is anyone interested in adding to your order next time you purchase these BMS’s. I am keen but would like to share shipping.

I would.
This is for the 7-20S 200A JDB/LLT Smart BMS model

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Basically to partner with @Louisvdw 's new BMS driver for Victron, etc

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I’m game … I have a part or two more I want …

Here it is:

My suggestion:
BMS comes with Bluetooth, so for $5 extra, add another UART port to interface with Louis Venus Software AND you can see the BMS on your phone using the Bluetooth function.

Then I think it is also $5 from the same supplier, I want 2, get this little boxy, instead of the open component:

This is how it looks without the boxy:

My test bed setup, this is for the 24v configuration:

This is how the wiring works:

So for 24v / 48v configuration - 72v, just keep on connecting the wires per cell:

Im in. Would like the 200A unit and all that is needed to connect this to MP2 and phone via bluetooth.

What is the feeling on when we want to do this buy?

I hope to send out invoices today, place the order … call it 1-2 days.

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When I enquired they said they did not have the BMS suggested. I suspect that they were just not keen on selling two units. They said they would get back to me when it was back in stock but that was about 2-3 weeks ago.

Jip, no stock ito drama with parts and all that in China … think the USA has some finger in that pie …

Our collective order is ready to be placed.

Right, the order is at final last ready for the Jaibiada 24v/48v BMS’s with RS485 port added.

Will be flown in.

Are you going with the newer 200A solenoid Jiabaida model?

Maybe next order. The ones I like and everyone bought with me can do 24v and 48v, dependent on how you connect the balancing wires.

And it comes in a TTT proof casing see. :stuck_out_tongue_winking_eye:

But yes, methinks I would want to “try” one, will order more later, after having sold my then weeks old tried and tested “new” BMS.

I am in discussion with the Jaibaida rep on Alibaba at the moment.
I wanted longer balance leads, the other outlet I was looking at had 0.4 m leads, which I think will be too short. This lot does 0.8m leads with I think will probably be OK.
If you want longer you have to order 50 units.
I don’t know prices China has clocked off for the day.
The thing is though the NTC leads for the temperature probes are still short.
I don’t quite understand that logic.
Anyway, they seem reluctant to tell me the NTC model involved and again it’s 50 units if you want longer.
There were 3 temp probes on the other BMS model I was looking at, (I think there is only one on the newer 200A model).
Anyway, I just thought I’d let you know if you are doing a group buy it may be a viable option for you. Better to know and not use the option, than not to know about it.

Before when I was placing the order, I could get free extra balancing wires … it did not seem to be an issue, as I’m under the impression I’m buying direct from JBD.

Would 0.8m length not affect the voltages and sending?

The BMS I now have has I think 3 sensors, two seem to be inside and 1 outside, and the outside one with very short wire like you say.

I have wondered about that, it being for the enclosure or for between cells … ?

I am as well. My place is:
Dongguan Jiabaida Electronic Technology Co., Ltd ?

Yes, but in practical terms No.
Yes, it is a variable resistance and any added resistance will affect the reading.
I don’t know what model NTC is used but commonly available ones are of standard resistances at 25 deg of:
1 MΩ
50,000 Ω
10,000 Ω
3,000 Ω
2,252 Ω
So you see adding maybe a quarter of an ohm extra, will only make a negligible difference.

I can only see one external NTC on the newer 200A, but the other model I looked at had 3 external NTC’s all short.

Well, Victron ( who I assume knows best) attaches the probes to the actual cells.
I suppose you have the freedom to set the temperature trips, so you could use ambient in snow countries.
Alternatively, it may be of interest to know how hot the BMS is getting.
I don’t actually know, some of this will depend on how @Louisvdw 's driver works.
I think without a BMS, Victron has simultaneous options for BMV probes, Inverter probes Venus probes and probably charger probes that can be hooked up to VRM. My understanding is the highest temperature measurement of all of them is what decisions are based on.
So maybe you only want the BMS to know about its own temperature and not report it to Venus, I don’t really know at this point.

I still have my inverter temp sensor connected to the batts. I just watch the ambient temp, cause in my mind to properly do temp sensing, is to do it per cell.

I agree with this, I think controlling decisions should be based on the temperature of my 100K batteries not my 1K BMS.

EDit: If this is how it can work I am not bothered about getting long NTC leads.

@TheTerribleTriplet , just as a matter of interest are there any distinguishing marks on that external NTC on your BMS, or is it covered in heat shrink?

Covered in a nice metal box … I opened the previous one ONCE … and NEVER again. :laughing:

Did not take note of the parts. Sorry.