Having issues with new battery.

[skwirl]

I have a small system in my shed. I bought a new Power Queen 12v 200ah selfheating lifpo4 batt to use this winter. I built a insulated box for it. My original batts are Power Queen 12v 100ah selfheating connected in paraell. I'm using a Power Queen charge controller, and a Renogy 12v 2000watt inverter.
All this worked very well since April of this year, no problems at all.
The problem is the new battery. When I try to connect it to the inverter the voltage drops to 8 volts then 0 volts. The bms is cutting it off.
The capacitors in the inverter are retaining 4v or so when it's disconnected. This seems to be causing my new batt to shut down.
I dont understand why?
I think the bms is bad in the new battery, maybe.?
I have switched back to the old batteries 3 times already and they work.
Thoughts, ideas, suggestions how to get my new batt hooked up and working or prove the bms is bad.
Yes, I'm spoiled now, I love having electric in my shed, I need it to work.

 

[Zapper77]

I have a small system in my shed. I bought a new Power Queen 12v 200ah selfheating lifpo4 batt to use this winter. I built a insulated box for it. My original batts are Power Queen 12v 100ah selfheating connected in paraell. I'm using a Power Queen charge controller, and a Renogy 12v 2000watt inverter.
All this worked very well since April of this year, no problems at all.
The problem is the new battery. When I try to connect it to the inverter the voltage drops to 8 volts then 0 volts. The bms is cutting it off.
The capacitors in the inverter are retaining 4v or so when it's disconnected. This seems to be causing my new batt to shut down.
I dont understand why?
I think the bms is bad in the new battery, maybe.?
I have switched back to the old batteries 3 times already and they work.
Thoughts, ideas, suggestions how to get my new batt hooked up and working or prove the bms is bad.
Yes, I'm spoiled now, I love having electric in my shed, I need it to work.

You need to charge the capacitors.

 

[timselectric]

You may need to precharge the capacitors.
It could be too much surge for the new BMS.
Why are you switching batteries, if the old ones worked?

 

[skwirl]

Thanks for the idea.
So how I would I precharge the capacitors?
Use a different battery to precharge?
I have a portable car jumper pack, connect that to the inverter to precharge?

The 2nd battery will eventually go in the girlfriend's shed when I get the remaining components.

 

[Kenny_]

Precharging:

Basically you connect the battery through a resistor for a few seconds... something like a 30 ohm 25 watt or so...

This will lower the current and allow the caps to charge up. Then take the resistor out and connect battery directly.

Will:

 

[skwirl]

Used the search on here.
Off to find a light bulb.
Thanks.

 

[BKY2003]

looks like the guy had some of the same problems. He does a tear down. On his it was the BMS

 

[Q-Dog]

Thanks for the idea.
So how I would I precharge the capacitors?
Use a different battery to precharge?
I have a portable car jumper pack, connect that to the inverter to precharge?

The 2nd battery will eventually go in the girlfriend's shed when I get the remaining components.

Yes, I don't see why a lead acid battery would not do it. You will still get a spark, but no BMS to flip out.

 

[skwirl]

Well, it's just not working. I recharge the inverter and connect. All good to that point.
The charge controller is NOT connected yet.
I turn the inverter on and few seconds later the ground fault trips on the inverter and the battery has shut down again.
I'm putting my original batts back on the system and try to return this new battery for a refund.

 

[skwirl]

Just finished putting my 2 original batts back. These connect fine, no errors with the inverter, charge controller or batts.
Has to be a bad bms in the new batt.
Hopefully Power Queen will let me return it and refund the cost.