EG4 batteries going into fault condition when connecting to inverter

[SunbeltLocked]

I have (2) EG4 48v 100ah batteries from SS. They are in parallel and charged to ~53vdc. I have a shutoff switch with a fuse going to a VFX3648 inverter. I'm using a Classic Lite 150 cc which is not in the circuit. I turn on the breakers for the batteries and everything looks fine, but when I close the switch to the inverter, the batteries going into a fault condition - the red light goes on. I tried running the battery monitoring software that came with the batteries, but it doesn't seem to be working. The only thing I know to do is hook up (4) 12v batteries in series to see if the inverter comes on. Which is what I did several years ago and it worked.

 

[John Frum]

The bms has probably tripped on the in-rush current to fill the inverter's capicitors.
The battery has an built-in pre-charge circuit.
The doco should explain how to use it.

 

[Bluedog225]

@SignatureSolarUS
@SignatureSolarJames

I don’t know where Richard doesn’t come up.

There have been issues. Hopefully they can help.

 

[LithiumSolar]

I think you need to turn the breakers on both batteries OFF, then turn your inverter control switch ON, then lastly turn your battery breakers ON. This will engage the pre-charge circuit in the battery to prevent the inverter inrush from tripping the BMS.

 

[SunbeltLocked]

OK, I hadn't thought of doing that. That makes more sense. I'll try that right now and let you know how it goes.

 

[Koldsimer]

I think you need to turn the breakers on both batteries OFF, then turn your inverter control switch ON, then lastly turn your battery breakers ON. This will engage the pre-charge circuit in the battery to prevent the inverter inrush from tripping the BMS.

Give this method a shot. If it doesn't work, use your charge controllers to quickly supply steady dc power to your inverter then turn on batteries. If this doesn't work, good luck.

 

[SunbeltLocked]

Hotdam, that was it! Now to put the cc into the ckt and run the local app. Thanks guys!