Portable EG4 Power Station

[SolarGear]

Hi All,

I am looking at creating a rather large portable EG4 power station and the equipment will be housed in a enclosed trailer that will be for rent. The idea at a high level is as follows:

1. 4x EG4 12000XP Inverters
2. 8x EG4 Indoor wall mount batteries
3. Roof mounted panels - my guess, around 2 KW in total solar input
4. 1x AC unit to keep the environment cool and dehumidified
5. A whole bunch of receptacles where various items can be plugged in

The solar panels will simply be there as a safety net and serve no other purpose beyond that. The last piece of the puzzle is how do I keep the batteries charged....

My thought is to use a EV charger connected to the grid and/or make use of a public charging station with only a J1772 plug. I need some suggestions on how I can control the max power draw based on the charger without having to keep changing the inverter settings. My understanding is that the J1772 has a signal wire that will let the car know how much power it can draw from it. Can this be used to automatically change the inverter settings locally? Is there something out in the market that can already do that? Would AC coupling be an option that the inverter will only grab what's given to it? I might be missing something completely obvious and trying to wrap my head around this.....I have 0 in depth technical knowledge on EV chargers so any help would be appreciated.

Something else to consider, how do I control the charging to stop when the latch on the charger handle is lifted to avoid AC arc? Use contactors that would automatically open when the button is pushed?

 

[DIYrich]

Chargeverter (one or more) to charge the batteries directly.
I have no idea how to fake the J1772 signal.

Electric car "J1772" charger - "pilot" signal sequencing with passive circuitry

J1772 Some background: Many electric cars are designed to use a "J1772" charging point. The main signal in the J1772 specification is called the pilot. Long story short, the car is expected to p...

electronics.stackexchange.com

With 115kW (roughly) of battery, you want a max charge rate of about 25kW, and take about 5 hours. A 50amp RV plug can provide about 10kW on a continuous basis.

 

[yabert]

I have no idea how to fake the J1772 signal.

It's possible to simply buy (or build) a J1772 controller for 40-50$.
Generally call J1772 Active Vehicle Control Module.

 

[Brucey]

My thought is to use a EV charger connected to the grid and/or make use of a public charging station with only a J1772 plug.

One thing to keep in mind, the vast majority of ev charging spots aren't designed for pull through for trailers. If using an f150 lightning towing a trailer for example, you have to take up a bunch of spots or unhook from trailer first.

Also there often a premium pricing to level 2 or 3 type charging due to demand charges etc. Don't expect your potentially cheap home residential rate. In California I think supercharging is over 50 cents per kWh.

 

[SolarGear]

One thing to keep in mind, the vast majority of ev charging spots aren't designed for pull through for trailers. If using an f150 lightning towing a trailer for example, you have to take up a bunch of spots or unhook from trailer first.

Also there often a premium pricing to level 2 or 3 type charging due to demand charges etc. Don't expect your potentially cheap home residential rate. In California I think supercharging is over 50 cents per kWh.

The idea would be to unhook the trailer for a few hours to recharge over night. Our local level 2 charge costs 0.20 cents per kwh to charge on a level 2 charger, so I am not too concerned. I am in Canada though....

 

[SolarGear]

Chargeverter (one or more) to charge the batteries directly.
I have no idea how to fake the J1772 signal.

Electric car "J1772" charger - "pilot" signal sequencing with passive circuitry

J1772 Some background: Many electric cars are designed to use a "J1772" charging point. The main signal in the J1772 specification is called the pilot. Long story short, the car is expected to p...

electronics.stackexchange.com

With 115kW (roughly) of battery, you want a max charge rate of about 25kW, and take about 5 hours. A 50amp RV plug can provide about 10kW on a continuous basis.

So it looks like the ford chargers can do up to 80amps AC Charge if I were to charge from home and hard wire a charger into my main breaker panel....

 

[SolarGear]

It's possible to simply buy (or build) a J1772 controller for 40-50$.
Generally call J1772 Active Vehicle Control Module.

Thanx! Any ideas on controlling the generator inputs though on the inverters though? Or would the charger control the max current even uf the inverter wants more?

 

[Brucey]

A whole bunch of receptacles where various items can be plugged in

So you have 48kW of potential inverter output and 112kWh of battery. I would suggest running maybe four 50A outlets to breakout boxes via extension cords so you dont have 10 or 15 things plugged into the side of the trailer?

What kind of loads will be attached? Wondering if it would be best to have the four 12ks running separately so you have some redundancy if one or two go down. If they are paralleled together and there's an issue you are going to lose all output until you reconfigure.

 

[Brucey]

So it looks like the ford chargers can do up to 80amps AC Charge if I were to charge from home and hard wire a charger into my main breaker panel....

Looks like it's worth waiting for the enphase 80A unit:

https://www.reddit.com/r/F150Lightning/s/9W18Drmw1k

 

[SolarGear]

So you have 48kW of potential inverter output and 112kWh of battery. I would suggest running maybe four 50A outlets to breakout boxes via extension cords so you dont have 10 or 15 things plugged into the side of the trailer?

What kind of loads will be attached? Wondering if it would be best to have the four 12ks running separately so you have some redundancy if one or two go down. If they are paralleled together and there's an issue you are going to lose all output until you reconfigure.

Thats not a bad idea! There is the potential for overloading a single inverter, so I might do 2 pairs of 24kw each. My idea is to rent it out to construction sites until they get permanent power installed. They could be running various types of equipment, so there might be a 30amp recepticle and a few 20amp ones per inverter pair. It might also be rented to homes during a power outage for users to run the necessary appliances. Fridges, tv, etc. Could be possible that multiple homes could connect to a single trailer. The possibilities are endless and the positive is its quiet!

 

[SolarGear]

Looks like it's worth waiting for the enphase 80A unit:

https://www.reddit.com/r/F150Lightning/s/9W18Drmw1k

Makes sense. My question still remains, how do I control the charge rate depending on the charger that is connected....in desperate need on an expert here....

 

[yabert]

how do I control the charge rate depending on the charger that is connected

What are you talking about? The charger is inside your equipment and you control it.
You only need to know what the EVSE (charge station) can give. If this one can give 30A, the charger should pull only 30A. This is the function of the J1772 Active Vehicle Control Module.
That give 7.2 kW at 240V and as you plan a 115 kWh battery at 51.2V this mean a single Chargeverter will never trip a 30A EVSE and give you over 5 kWh each hour.
Almost every EVSE in are 30A or more.

 

[SolarGear]

So the plan is not to

What are you talking about? The charger is inside your equipment and you control it.
You only need to know what the EVSE (charge station) can give. If this one can give 30A, the charger should pull only 30A. This is the function of the J1772 Active Vehicle Control Module.
That give 7.2 kW at 240V and as you plan a 115 kWh battery at 51.2V this mean a single Chargeverter will never trip a 30A EVSE and give you over 5 kWh each hour.
Almost every EVSE in are 30A or more.

The idea is to use the generator port on the inverter's to charge the batteries. and not use a chargeverter. The thought is to be able to pull up to any level 2 charge station and initiate a charge through the j1772 port without having to manually change the inverter charge settings based on the max amps of the charger. I have no idea if this is even possible.

If I am understanding correctly, the J1772 Active Vehicle Control Module would control the max output of the charger, even if the inverter "says" it can do a lot more? Or am I missing something here?

 

[yabert]

The idea is to use the generator port on the inverter's to charge the batteries. and not use a chargeverter.

Oh! I understand better now.
Based on EG4 spec, all the generator settings look to be set manually, so probably no easy way to change some parameter based on the power available from the EVSE.
Parameter like Generator Charge Battery Current(A) or Max. Generator Input Power(W).

Still, most EVSE (if not all) can supply 30A or more (up to 80A) at 208V or 240V. So, worst case you can set max generator input at 6kW and use every EVSE regardless of their power without problem.
That still around 65 kWh add to the battery over night (12h period and 90% charger efficiency).

 

[yabert]

Ummm! Is I find a problem with your plan?
From EG4: NOMINAL AC VOLTAGE (GRID | GENERATOR) 120/240VAC; 120/208VAC (L1/L2/N required)
Please note that EVSE don't have neutral and simply use L1/L2/Ground.
Look like you are screw to use a chargeverter.

 

[SolarGear]

How about AC couple? I should probably go through the manual, see what would be possible and perhaps reach out to EG4 and see what they could do. I deal with 10 different inverters/systems daily, it's hard remembering everything, lol