JBD Bms settings look correct /do I need to balance?

[Schweg2]

Guys,
I have 2 battery banks and it seems bank 1 is out of balance that I top balanced initially.
What do you think?

Also what do you suggest my BmS settings be at, I would like to cap charging at 80-85%.
From what I’ve read they say not to balance until 3.4v?
It seems my settings got goofy on me.
I’d appreciate any help.

 

[sunshine_eggo]

There is no way to charge to 80-85% based on voltage. It's pretty pointless to do. Charge to 3.45V/cell and be done with it. You'll get to 98%+ SoC and minimize charging associated stress and maximize capacity.

Disable "Bal only when charging"

 

[Rednecktek]

I always set my balancing voltage lower so it works longer. I always thought disable only when charging disabled balancing completely. I'm gonna have to play with that when I get home.

 

[#40Fan]

Andy on Off-Grid Garage on YouTube has some very good and detailed videos of BMS settings including charge voltages, balancing times, etc. Ignore all of the shit he tries to sell you and you'll learn a lot.

 

[Schweg2]

There is no way to charge to 80-85% based on voltage. It's pretty pointless to do. Charge to 3.45V/cell and be done with it. You'll get to 98%+ SoC and minimize charging associated stress and maximize capacity.

Disable "Bal only when charging"

I now have that toggled off and lowered to 3.45.
Problem now is battery gets fully charged and triggers overload in bms.

My inverter is a Growatt 12000 Dvm-mpv. Is there a setting to fix this issue?
Currently I have bulk set at 56.4 and 54v float.

There must be a setting to tell the inverter to stop charging…right? Or is that “float”

Thanks

 

[TomC4306]

I now have that toggled off and lowered to 3.45.
Problem now is battery gets fully charged and triggers overload in bms.

My inverter is a Growatt 12000 Dvm-mpv. Is there a setting to fix this issue?
Currently I have bulk set at 56.4 and 54v float.

There must be a setting to tell the inverter to stop charging…right? Or is that “float”

Thanks

Drop bulk to 56 volts and try that.

 

[TomC4306]

There must be a setting to tell the inverter to stop charging…right?

Yes, charge voltage. It's physics.

 

[Substrate]

Well, 3.400v is what's known as the "knife edge" for the balance start trigger.

This is at the very bottom of the differentiation between the normal flat-line charge, and the upper charge knee. With your setup, I'd definitely change that to at least 3450. Usually 3500 is in the middle of the upper charge knee. Top balance occurs when one is in the knee, not at the bottom.

When set to 3.4v, there is still a LOT of current flowing, and the minimal bleeder-resistor circuit is more or less an annoyance and possible UNbalancer at that stage. Just stressing the resistor for no real gain that low in the knee.

If the balance-trigger voltage is say 3.5v, then less current is flowing when it kicks in, and the resistor has a larger effect upon proper balance.

But an urban myth developed that setting the trigger to 3400 was a way to keep cells from running away, but it is only a mask for an improper initial balance, or having to do those pesky 10-20 usage cycles before the bms stops overvolting when the rice-grain sized resistors finally have had enough time.

 

[mikefitz]

have that toggled off and lowered to 3.45.

The suggestion to use 3.45 volts was a charger setting, not a BMS setting. Revert to the default 3.65 volts as the high volt cell protection limit.