I threw this open RFQ to all BMS suppliers on Alibaba …
Ideal Specifications:
FETS. In high power applications, usually MOSFETs.
FET = Field Effect Transistor. MOSFET is one kind of FET, the “metal oxide semiconductor” kind.
If tonight between 2AM and 3AM you don’t know what to do, check it out. They are quite impressive, since they don’t amplify current like their BJT brothers, but only need a voltage to switch them on. They do however have capacitance on the gate, so you have to hit them hard (literally one or two ampere for a split second) to turn them on hard.
They don’t have a constant voltage drop (BJT is usually around 0.6V to 0.7V constant, which makes them unsuitable for high current low-voltage applications these days), and if you spec it right they have low forward resistance, but… unlike a BJT, they conduct in reverse, so in order to have directional control you need to put two in series.
And usually just one isn’t enough for the current levels of a battery, so you will usually have a bank of them 
But generally, if you ask about directional charge/discharge blocking using FETs, battery makers should know what you are on about.
Hi guys,
We would probably be able to add it for you, but we would need the protocol documents of the battery/bms, and also a little piece of source code that shows how to talk to the bms. If source code is not available, we can work from the protocol documents, but then it takes MUCH longer, as we would need a battery to test with, figure out the protocol document and write code bit by bit until all the functions of the bms is done, whereas a little source code (regardless of what language) is a much quicker development cycle.
PS, have a look at https://centurionsolar.co.za/solar-management-hub/, we are busy upgrading all our pi’s to the latest version, called SMH 
Regards
Johan
I’m learning to speak Chinese very fast …
At the MOMENT, testing to still confirm this, it appears that the first BMS I so much like, has a LOT of ticks.
Must Have Specifications: AP20S003 - and it comes in a nice metal box …
Good to Have:
Nice to Have:
I’m now finding out which Jaibaida BMS’s models do have separate charge/discharge FET’s / Relays, as it is “hidden” in all the translated English.
So far, methinks, this model BMS could be a winner.
Even here the JBD BMS’e seems to be most liked.
Just note that the Americans do like their 12V (I think it is all those campers), so that JBD is a 12V version.
Mine looks the same but is the 15S 48V model.
Few balancers are active, and those that are cost a premium. You use that expensive balancer once (when the battery is new) and then once in a blue moon (after a large discharge)… and the rest of the time it does nothing.
It’s a nice-to-have in my opinion, not a need
To add a active balancer right at the start, yeah, does not make a lot of sense, I agree.
But I’m not thinking the first few weeks, months of a new bank. I’m thinking of the years to come.
Think Will made the comment, stand to be corrected, that it could be an idea to keep an active balancer around.
After my fiasco with the Daly and the 150ah cells, an active balancer could maybe have helped … but, I’m so over that now.
How to make a bank last a decade, even 2 … NOTHING stops one from adding a active balancer after a few years, long before some cells go “off center”.
Time will tell.
I’m currently running some test with a JKBMS that comes with active balancer. So far it looks like a very nice BMS.
Which boxes does it tick as per above?
Nothing wrong to have more than one option ito BMS’es to get.
It does not use the Xiaoxiang App, but I have the Voltage, Current and Power working already in the driver.
Then it does not do parallel that I know.
The rest it can all do.
Does anyone know what import code to use for BMS’es?
Code 8507.90 or 8542.90
We don’t want drama with SARS on arrival.
I don’t like either of those.
How about 8542.31?
Electronic integrated circuits:
8542.31 - - Processors and controllers, whether or not combined with
memories, converters, logic circuits, amplifiers, clock and timing
circuits, or other circuits
LAPD-LPrim-Tariff-2012-04-Schedule-No-1-Part-1-Chapters-1-to-99.pdf (2.6 MB)
This (I think) is the latest tariff schedule. It is amended very regularly, so it is always best to get the latest version.
Busbars, still 8507.80 you recon?
I use
8542.3 Integrated circuit - battery controller
That sounds even better.
I don’t know, but this would probably work. There seems to be a few codes for bars depending on what they are made of. A lot of them attract a tariff.
But, I suppose “battery parts” 8507.90 would work. I doubt you’ll be hanged for it, if you’re wrong.
the more numbers the more details. It’s a subset. So yes
