Cargo Trailer batteries - Server rack or wall-mount? EG4 vs SOK vs ?

[mattleonard]

I'm spec'ing out a 5x8 cargo trailer build - for powering small concerts, festivals etc. Likely starting with a EG4 6500ex unit, with the possibility to add a 2nd unit in a few months for true split-phase/50a operation. For batteries - I'm in the debate of server-rack (EG4 or SOK likely) vs a wall-mount like the EG4 PowerPro - I'd like to have ~15kWh to start, and if/when I add a 2nd inverter I'd add more battery capacity accordingly.

I like the server rack option - as I could put them in a proper 19" rack with casters (a true heavy-duty road case, not the OEM ones they sell!), and wheel them in/out of the trailer for modularity, maintenance, storage or smaller events where I don't need the whole trailer etc. But that does seem like a larger footprint, vs strapping a PowerPro flush on a wall and keeping more floor space clear. But I'm also worried about the significant weight of the PowerPro mounted on a somewhat flexible cargo trailer wall and bouncing around down the road.

And relatedly - EG4 or SOK batteries? I'm assuming the LL/Pro versions as the communications & pre-charge circuit are useful to me. Since I don't plan to use an EG4 rack with the built-in bus bars - I don't like the small lugs, and this would limit paralleling units in shifting configurations (capacity, and physical layout). I can imagine occasionally using just 1 or 2 batteries for a smaller modular setup. The SOK terminals would give more flexibility here - but also seeing some reports about communications issues between EG4 inverters and SOK batteries.

Any feedback is helpful - thank you!

 

[justinm001]

I have both and would go SOK all day everyday. On a 5x8 I'd worry about weight distribution most and definitely wouldn't want a heavy battery hanging on the wall. Ideally put them vertical in the front, it'll only take a few inches of floor space.

The batteries are about 100lbs each so 3 of them in a rack with casters seem hard to load/unload without a ramp

 

[mattleonard]

I have both and would go SOK all day everyday. On a 5x8 I'd worry about weight distribution most and definitely wouldn't want a heavy battery hanging on the wall. Ideally put them vertical in the front, it'll only take a few inches of floor space.

The batteries are about 100lbs each so 3 of them in a rack with casters seem hard to load/unload without a ramp

Well, ramp is definitely a given - but thinking (2) racks of (2) batteries each - 8u racks. All manageable on wheels, and could be lifted by a team if need be (I work in audio/production world - racks this heavy are common).

What inverter are using with the SOK batteries? Communications work?

 

[Shimmy]

I'd think the "waterproof" EG4 battery would be a better bet in that kind of scenario; does the trailer have a suspension? You are going to need something to help manage vibration I would think.

Another option would be to look at the Trophy 300Ah batteries (maybe integrated onto a hand truck if you want portability).

Just how much "other stuff" do you need to fit into the trailer?

Have you seen @MrM1's build?

 

[12VoltInstalls]

You’d have to engineer something to reinforce the walls of the utility trailer, but personally (having worked for a utility trailer dealer outfit and modified or custom built a number of them) but floor space/horizontal surfaces are at a premium in a small trailer. I’d be inclined to wall mount on both the sides just ahead of the axle centerline, balanced and vertically, two on each side. But your option of mobility may negate that if it’s no compromise.

 

[HarryN]

There is a lot of vibration in a trailer going down the road.

Server batteries are designed for stationary use.

The ideal situation is to use a battery based on cylindrical cells if possible.

I am in the east bay as well - lots of us I guess.