Need help with upgrading an inverter

[sjvicker]

At my camp property I currently have 2kw of panels, a Victron 150/45 charge controller, 2 12v LI batteries (24v system) and a Giandel 3kw 24v inverter. This system has served me well for camping (ok glamping) and working from the property however next year my wife and I are planning to move to the camp property and live out of our trailer full time while we build our shop w/appt and full scale solar system at the other end of the property. Our loads will increase during this time and we'll need the security of being able to charge the system with a generator if needed.

I am planning to upgrade the 12v LI batteries to a 48v EG4 battery, I want to be able to charge with my 2000w generator, I want 5-6k of pure-sine power and I do not need split phase power but I'm not certain about what inverter I should get and am looking for recommendations.

Option 1: Buy an all-in-one inverter/cc. Something like the Sungold SP6548 or stacking 2 EG4-3000EHV's might be a possible solution.

Option 2: buy a new 48v inverter and a separate charger (such as the EG4 Chargeverter).


I will likely buy an EG4 18k system next year for the full scale system so I'm leaning towards an all-in-one for this camp system just so I can learn more about them before dropping major $.

thoughts?

Thanks

 

[sunshine_eggo]

Option 1: Count on an 80-100W continual drain due to idle power draw, This will consume nearly 50% of your proposed battery simply having the inverter turned on - no loads.

Option 2: Not much better than option 1, but almost certainly necessary with your small generator.

Option 3: Victron MP-II 48/5000. It doesn't meet the 6kW number, but they have true surge and can run at or above continuous rating for 30 minutes or more. I run a 37' 50A 5th wheel off a single Quattro 48/5000. I can run both A/Cs at the same time, no soft starters. At 15W idle, this unit will only consume 7% of your battery.

Hopefully, you see the lower cost of the AiO has a penalty. If you can only use 50% of your battery for loads, that's like spending $750 on battery you can't use rather than $105. That also translates to the array. The first 400-500W of your array will go to replenishing the energy consumed by the inverter with an AiO leaving only 1500-1600W for useful loads/charging. With the MP-II, only 72W of your array is feeding the inverter leaving >1900W for loads/charging.

Victron inverter/chargers are also extremely tolerant of dirty generator power, AND they have powerassist. When you're on generator power, the generator is powering both your loads and your charging. if you exceed the generator power with either, you'll overload the generator.

Powerassist is set to protect the generator. If it senses a load larger than the allowable generator input current, it stops charging, starts inverting and BOOSTS the generator to help power the loads preventing generator overload. Once the loads drop, it resumes charging the battery with any surplus generator power.

 

[sjvicker]

good point on idle draw. Those MP-II 48/5000's seem like a pretty new product and there's not a ton of availability yet.

If my batteries drain below the inverter threshold, will the Victron inverters turn back on automatically once voltage comes back up? I power a few cameras and Starlink and with my current setup and if the batteries drain overnight or due to not enough solar input I have to manually restart the inverter.

 

[sunshine_eggo]

good point on idle draw. Those MP-II 48/5000's seem like a pretty new product and there's not a ton of availability yet.

New-ish. IIRC, MP-II has been out since 2019.

They're an evolution of their prior hardware.

If my batteries drain below the inverter threshold, will the Victron inverters turn back on automatically once voltage comes back up?

Provided the inverter disconnects based on voltage, yep:



If it disconnects due to BMS voltage protection, the surge from cap charging may trigger BMS short circuit protection, and it may not startup reliably due to the BMS thinking the battery terminals are shorted.

I power a few cameras and Starlink and with my current setup and if the batteries drain overnight or due to not enough solar input I have to manually restart the inverter.

You may have discovered that the Victron MPPT will power exclusively from PV even if the batteries are in low voltage protection or even disconnected. This can be a safeguard to the cap surge issue. The MPPT will charge the inverter caps removing the BMS perceived short circuit.

So in either case, the inverter should restart, but when it happens due to BMS protection, it may be inconsistent/unreliable. This will be true for any inverter subjected to BMS based discharge/low voltage protection.