LIFEPO4 Battery/2000W Inverter issues

[Pass me]

Hi folks, well today I learned the BMS in my 12V 100Ahr LiFePO4 battery will not allow my 2000W Inverter to run. I've googled this a bit and understand the initial Inverter capacitors demand (Volts? Amps? Dunno) exceeds the max my BMS will allow so it steps out.
I only found this out when my Noco Genius10 charger - permanently connected to the battery, would quit when I connected the Inverter. Took a minute r so but it quit charging and indicated "voltage above protected limit".
If I've got this right is there a way around this anyone?

 

[solarman]

this is one of the problems running high wattage inverters off 12 Volts. initial surge currents are high and
your BMS is shutting down to protect the battery.

you have several options to mitigate the situation.

1. use a smaller inverter
2. add another battery in parallel giving 200A capability
3. change battery to one with a 200A BMS

 

[Lou Schneider]

The Voltage Above Limit error says the input capacitors on the inverter are smoothing out the charger's waveform (like they're supposed to do) and confusing it's logic. I'd contact Noco and see if they have a solution.

 

[Pass me]

Great suggestions both and I thank you. My hunch was to connect the Inverter to the house battery instead... now i will.I've never had an issue with this Inverter with previous (450Ahr totsl) wet cell batteries before. My current trailer has a single 70Ah lead acid type. It is enough for my trailer needs but as I wish to have 120AC occasionally I installed the LiFePO4. It is connected in parallel to the house battery via an RV on/off switch. When disconnected the generator recharges the house battery, my Grenius10 charges the Lithium one and when done I boondock with both batteries connected. Not ideal but it works.
As an aside I will email Noco to see if they have a recommend around this situation.
And to the latest response to this post....the Inverter is turned off/zero load when I connect it to the Lithium Battery but as mentioned by solarman I would need a 200A capable BMS type battery to connect my 2000W Inverter.
Thanks again everyone and if I'm still missing something please let me know.

 

[Lou Schneider]

Great suggestions both and I thank you. My hunch was to connect the Inverter to the house battery instead... now i will.I've never had an issue with this Inverter with previous (450Ahr totsl) wet cell batteries before. My current trailer has a single 70Ah lead acid type. It is enough for my trailer needs but as I wish to have 120AC occasionally I installed the LiFePO4. It is connected in parallel to the house battery via an RV on/off switch. When disconnected the generator recharges the house battery, my Grenius10 charges the Lithium one and when done I boondock with both batteries connected. Not ideal but it works.
As an aside I will email Noco to see if they have a recommend around this situation.
And to the latest response to this post....the Inverter is turned off/zero load when I connect it to the Lithium Battery but as mentioned by solarman I would need a 200A capable BMS type battery to connect my 2000W Inverter.
Thanks again everyone and if I'm still missing something please let me know.

You need a 200 amp BMS to run the inverter at full power. A single 100 amp BMS will let it run up to 1200 watts. I would remove the 70 a/h lead acid battery as it may keep the LiFeP04 from fully recharging.

 

[John From Detroit]

Amps the initial surge is ... rather high. Adding a 2nd battery and perhaps a "hardening capacitor" or two (high end car audio store item) might help. The high value "Hardening cap" acts a bit like the pressure tank in a water system Can provide many amps but only for a short period of time but may be enough to kick start the inverter.

 

[Pass me]

I've just tried to find info on the BMS configuration but not surprisingly this is what I got back....
"Moseworth 12V 100Ah battery has an upgraded BMS with overcharge, overdischarge, overcurrent, short circuit, and low/high temperature cut-off protection. The specific BMS parameters are not listed, but the battery has a 5-year warranty and professional support."
Yes you get what you pay for, in this case a 100Ah Lithium Battery for ~$170 American. I'm happy with the purchase as it's a reasonable price to Kickstart my LiFePO4 batteries understanding. I'll limit my Inverter draw to 1000W and go from there.
Appreciate the support everyone!

 

[Gary RV_Wizard]

Add a second 100 AAH battery in parallel?

 

[Gizmo]

I agree with others who say add another 100 Ah battery. One 100ah battery is simply not enough. Alternatively, look at 1-lithium battery of 200-Ah or more.

 

[Pass me]

My immediate fix (later today actually) will be to connect the 2000W Inverter to the 70 Ah lead acid house battery.
I've done this before with no issues (5A AC short duration draw only). My LiFePO4 is connected to this battery through an on/off RV switch, when boondocking I link the two. When recharging via my generator (30A shore power cord) I disconnect the LiFePO4 (RV switch in the + lead), charge the house battery via the trailer PD9140 and the LiFePO4 via the Noco Genius10 charger powered by a kitchen 120V outlet.
I will post tonight how things transpire but I'm confident this will work. The learning curve here was the limitations of a LiFePO4 battery due to its BMS protections circuitry.

 

[John From Detroit]

I think (without looking) that the Xantrex recommends 200 AH per thousand watts by the way but I know a Prosine 2.0 (2000 watts) will work with 200 AH of lead acid.

 

[Gary RV_Wizard]

I think (without looking) that the Xantrex recommends 200 AH per thousand watts by the way but I know a Prosine 2.0 (2000 watts) will work with 200 AH of lead acid.

Depending on the max actual load and the characteristics of the amp draw, a Prosine 2.0 will "work" with an 8 AH lead-acid motorcycle battery. The issue here is the high peak load and the amp draw monitoring by the BMS. In this case doubling the number of batteries adds another 100A BMS, thus eliminating the bottleneck.