NEW 200A JBD BMS for sale

I have 2 x 200A JBD BMSes for sale.

They were part of the lot TTT brought in.
They have bluetooth and RS485
Comms with Venus OS possible if you load a driver on the OS.

Looking for R2000 per BMS…

I got hold of two BSL 6.4’s, and with limited time decided to hold off on my DIY batt builds.

Hi Willem

I will take both. Please message me your contact details.

As a matter of interest, why 20 S?

It is a 13s to 20s if I am not mistaken.

Just checked the manual. You are correct it’s a 13 - 20 cell bms…

Purely for information:
At the time of the last order, the chip problem was forcing us to get the 13s-20s version.

The version I’m personally very much in favour of, is the 8s-20s, meaning 24v OR 48v banks can be connected. Just opens up SO many more possibilities.

What makes the 20s interesting, one can have 17 or 18 cells on a 48v bank on Victron, as per @Phil.g00 musings. :wink:

The ONLY bleh issues on these JBD BMS’es, are the common charge/discharge port. I “get” why it would be a challenge for the MOSFETs on 280ah cells.

BUT, it is something one can manage … just don’t ever let the cells get out of balance. :slight_smile:

Why does common charge and discharge matter if cells are imbalanced?

If a cell hits 3.65v on a unbalanced bank, the BMS disconnects completely aka potential DC Ripple.

With charge/discharge being separate, it won’t disconnect i.e. will still allow discharging, which is what one wants.

BUT, I have NO idea what will transpire on the DC bus if the BMS stops the charging dead, with the MPPT still happily providing what is asked of it.

EDIT: As I’ve said elsewhere, from what I’ve done to date, dropping the charge current manually, using the Delta, is much more controlled, for the entire DC bus side.

It is only an issue if your charger does not know about it (i.e. it is not linked to the BMS and notified). Then yes the BMS will protect itself as TTT explain and if the charger still don’t listen it will disconnect the charge.
If your system is connected then this is not an issue.

But by having two batteries in parralel you should eliminate this problem. The BMS will then balance the cells and reconnect. But if you look at the levels commercial batteries are using for their charging limits then this should not happen…

Ok, so if using your BMS driver, then all good.

Yes the driver will make your BMS connected and will alert the charger if there is an issue and stop the charge.

This could solve the issue, except if both batteries have issues at the same time and disconnects.

The MPPT will charge up to the voltage it was told and stop. Since this will happen very quickly (it is only charging a bunch of electrolytic capacitors) you could say the MPPT will simply stop.

Of course there is a slight upwards voltage spike as it happens, and Microcare MPPTs were once known to blow up under such circumstances, but none of the other blue stuff suffers any bad consequences.

Yes. Which is why it is better to buy two smaller Pylontech units instead of one large one (as an example). A high cell in one module (aka string) causing that module to disconnect still leaves the rest of the battery fully operational.


Yes those battery parameters and also through alerts. GitHub - Louisvdw/dbus-serialbattery: Battery Monitor driver for serial battery in VenusOS GX systems