Dual Growatt 3000W AC coupled inverters, 15kWh LiPO4 batteries in my BH2800

[jdfritz]

Just thought I would share my project idea with you all.

I’ve always wanted to be able to park and have 120V AC power without starting a generator. After doing some measurements and researching I decided on going with dual Growatt 3000w inverters in parallel with 15kWh LiPO4 prismatic cells. The batteries are rated for 7000 cycles or 19 years at 80% I installed a 63A rotary switch in the electrical cabinet behind the breaker panel which is accessed from the cabinet next to the breaker panel. Oh boy what a job that was to fit 10 6awg wires into a rotary switch mounted in the 4x4x6” junction box but now I can easily switch from shoreline to inverters without unplugging the RV and I can also charge from shoreline power.

I ran 2 6/2 romex cables to the front compartment, 1 for powering the RV and the second is connected to the shoreline side of of the rotary switch for charging the lithiums at 5000W. Yesterday I got the diamond plate on the wall with inverters mounted and battery rack with batteries installed. Since the battery rack weighs about 380lbs I installed 2 65” steel channel beams 3/4x1.5” on the V tubes of the trailer frame. There is exactly 11/16 gap between the 5/8 plywood and the V tubes so a 2x4 and a floor jack worked perfectly to raise the floor 1/8” to install them. Then the battery rack was installed by drilling through the floor and channel beams. The storage compartment floor is more solid than ever and no more flexing.

The EG4 3 battery rack height is 24” and the compartment is about 26.5” so I had to put the rack together inside the compartment. That was so close to not fitting, I only had 3” clearance underneath to install screws with my 90° impact adapter and a short Philips bit.

I also added 2 Signature solar 12V 100ah waterproof prismatic batteries to the 12V side of my RVs power so I can run the 12V fridge and put the slide in and out without pulling the led battery voltage down to 12.2V. With the Lithiums connected to the lead batteries the voltage always stay 13.15 to 13.62V.

If any of you are wondering I measured tongue weight before and after the install. Tongue weight went from 800lbs (full propane x2, x2 12v led interstate batteries, x2 12v 100ah LiPO4) to 1,025lbs or an increase of 225lbs.

Here are a few photos of my project and will upload more as I complete it.

I will be installing 1.2-1.6kw of panels on the roof when the funds come in but for now I have AC power for when we travel between campgrounds.

[howson]

jdfritz -- what drove the choice of the Growatt and battery? (I know nothing about either of them.)

[jdfritz]

I use the 48V EG4 batteries on my house solar system. I haven’t found a better LiPO4 battery for the cost than these, 5kwh for $1500. Most LiPO4 batteries are rated for 2000-5000 cycles depending on the cell quality and are almost twice the cost than EG4. The 12V EG4 LiPO4s are $550, waterproof and rated for 7000 cycles compared to Battleborn at $999 and 3000-5000 cycles and not waterproof. I also prefer the flush screw terminal connector on the EG4 12V and Bluetooth BMS to monitor cells right on my iPhone.
https://signaturesolar.com/eg4-wp-li...ry-12v-100ahs/

For the Growatt inverters I wanted a compact all in 1 AC coupled inverter, 48V, with built in MPPT solar inputs with a voltage range of 30-120V DC. With AC coupling the inverter can run the 120AC loads directly off solar if it is sunny without inverting DC current from the batteries.

Examples:
RV power consumption 750w
Solar production 900W
Inverters will power the 120V RV outlets without pulling any amps from the LIPO4s while also charging the LiPO4 batteries with 150W.

RV power consumption 1400W with AC unit running
Solar production 1000W
Inverters supplement with 400W of battery power

[jdfritz]

Just completed the system today, here are some photos of the floor supports and completed wiring.

[Country Campers]

This is a very interesting install. I always like to see something different as there are a lot of different systems and ways to utilize them as technology grows.

Brian