“Mobile” 240 volt split phase backup system.

[S Davis]

I need help with designing a back up system, the plan is for it to be mobile and have a battery module or two and an inverter/solar module.

The goal is a reliable quality system that can be broken down and moved to remote job sites by two people. The plan is to use Victron products. Primary charging will be portable panels (amount and type to be determined) and generator.

I am starting with a 42 kWh battery bank, four 24v 304ah and two 24v 280ah, I am planning on using the lynx distributors and shunt for the battery section. All DC load wiring will use DLO cable.

I looked for a diagram that was similar but couldn’t find anything. Any help would be appreciated.

 

[sunshine_eggo]

This is split phase quattros:

https://www.victronenergy.com/upload/documents/Split-Phase-Quattro-system-with-Cerbo-GX-Touch-50-Discover-42-48-6650-Smart-solar-MPPT's.pdf

Everything you could possibly need is there... you just have to figure out what to omit.

 

[S Davis]

This is split phase quattros:

https://www.victronenergy.com/upload/documents/Split-Phase-Quattro-system-with-Cerbo-GX-Touch-50-Discover-42-48-6650-Smart-solar-MPPT's.pdf

Everything you could possibly need is there... you just have to figure out what to omit.

Would the Quattro be better than the multiplus? this will be a 24 volt system.

 

[HarryN]

Would the Quattro be better than the multiplus? this will be a 24 volt system.

Yes they are really designed for what you are trying to do. I have a quattro 5000 / 48 120 vac inverter at my shop (not in use right now) but they can really run in heavy loads and have features that the others just do not have.

IMHO, all of the other victron products on the market ride on the coat tails of the quattro, even though they are not nearly as good as it is.

Another path that you could go down is to look at Telecom type inverters like exeltech. They have models that actually can expand in capacity over time by adding on capacity. They are made in US vs victron are made I think in India if that matters.

One difference to keep in mind is that victron inverters are rated in VA and Exeltech are rated in watts.

In my testing, a 2000 watt Exeltech inverter was virtually identical to a victron 3000 unit in mixed inductive / resistance load capability - within what I could measure.

With the power level and weight that you are looking at, is it possible to set it up in an enclosed trailer and pull it to the site?

 

[sunshine_eggo]

Would the Quattro be better than the multiplus? this will be a 24 volt system.

No.

The Quattro is a Multiplus with a second AC input and different voltage/power options. The only reason I have a pair of 48V/5kVA Quattros is because they did not offer an equivalent Multiplus when I was shopping. If I had to do it over again, I would buy 2X MP-II 48/5000 that are UL pending.

Yes they are really designed for what you are trying to do. I have a quattro 5000 / 48 120 vac inverter at my shop (not in use right now) but they can really run in heavy loads and have features that the others just do not have.

IMHO, all of the other victron products on the market ride on the coat tails of the quattro, even though they are not nearly as good as it is.

How do you figure this? Most of their innovations happen on the Multiplus before the Quattro.

 

[S Davis]

Yes they are really designed for what you are trying to do. I have a quattro 5000 / 48 120 vac inverter at my shop (not in use right now) but they can really run in heavy loads and have features that the others just do not have.

IMHO, all of the other victron products on the market ride on the coat tails of the quattro, even though they are not nearly as good as it is.

Another path that you could go down is to look at Telecom type inverters like exeltech. They have models that actually can expand in capacity over time by adding on capacity. They are made in US vs victron are made I think in India if that matters.

One difference to keep in mind is that victron inverters are rated in VA and Exeltech are rated in watts.

In my testing, a 2000 watt Exeltech inverter was virtually identical to a victron 3000 unit in mixed inductive / resistance load capability - within what I could measure.

With the power level and weight that you are looking at, is it possible to set it up in an enclosed trailer and pull it to the site?

It needs to fit into a 4X4 truck or loaded onto a boat to get to some of the sites.

 

[S Davis]

Ok so question, I want to run split phase 240, can I do this with single phase 120 input for charging? Or do I need a 240v generator?

 

[sunshine_eggo]

Ok so question, I want to run split phase 240, can I do this with single phase 120 input for charging? Or do I need a 240v generator?

Yes, but you can only charge with ONE of them. You can't feed them both with 120V.

It requires you to DE-select "switch as group" when configuring them in parallel.

I have a cheap 120/240V Harbor freight Predator 3650 Generator for $400 or so. Works fine either way.

 

[S Davis]

Yes, but you can only charge with ONE of them. You can't feed them both with 120V.

It requires you to DE-select "switch as group" when configuring them in parallel.

I have a cheap 120/240V Harbor freight Predator 3650 Generator for $400 or so. Works fine either way.

Ok, thanks that really helps, I am planning on charging with a Honda 2200 inverter generator or two. Ok so limited to 70 amps @ 24 volts from one multiplus. I will probably need to add another charger.

 

[DIYrich]

24v 50ah battery weighs roughly 50 pounds. Keep that in mind for portability of a 304ah battery (300 pounds).

 

[S Davis]

24v 50ah battery weighs roughly 50 pounds. Keep that in mind for portability of a 304ah battery (300 pounds).

The cells are 13lbs each, they should weigh around 175lbs each in custom boxes.

 

[sunshine_eggo]

Ok, thanks that really helps, I am planning on charging with a Honda 2200 inverter generator or two. Ok so limited to 70 amps @ 24 volts from one multiplus. I will probably need to add another charger.

If in split phase, you can't feed 120V to each inverter. You must supply appropriately phased 120/240V to the inverters. So unless these generators can work in parallel with each other on a single inverter (still limited to 70A * 28V = 1960W), you need to get a 120/240V generator.

 

[S Davis]

If in split phase, you can't feed 120V to each inverter. You must supply appropriately phased 120/240V to the inverters. So unless these generators can work in parallel with each other on a single inverter (still limited to 70A * 28V = 1960W), you need to get a 120/240V generator.

Understood, the two was if I add a second battery charger and needed more amps @120v.

 

[sunshine_eggo]

Understood, the two was if I add a second battery charger and needed more amps @120v.

Have you priced 24V chargers capable of ~1600-2000W?

 

[S Davis]

Have you priced 24V chargers capable of ~1600-2000W?

No I assume they are not cheep but what is with this stuff, my 4/0 dlo is over $10.00 per foot and I don’t even want to talk about cast lugs.

 

[S Davis]

One of these would probably work.

Victron Energy CCH024060000 Centaur Charger 24/60(3) 120-240V​

 

[ricardocello]

The only reason I have a pair of 48V/5kVA Quattros is because they did not offer an equivalent Multiplus when I was shopping. If I had to do it over again, I would buy 2X MP-II 48/5000 that are UL pending.

I’m in the same boat. I’ll get the UL Muliplus for the next house.

 

[S Davis]

These are the custom 24volt 8s boxes, they will have 2ga silicon wire, 200amp breakers, single 200 amp front terminals, JK BMS with active balancing, Bluetooth and heat. The boxes will have the jk screen and on/off switch as well as network cable connections.

 

[mattleonard]

I'm building a similar rig - meant to be portable (wheeled by 1 person, lifted by 2), primarily for powering off-grid sound systems. Right now I've got (4) SOK Pro 48v server rack batteries. I have (2) 8u road cases with two batteries in each (so ~220lbs), with 2/0 ultraflex cable and Anderson SB175 connectors. They are on wheels and roll nicely, and 2 people can reasonably deadlift each case. Planning for a 3rd rack - so 30kWh of battery storage.

I'm still debating inverters - I'd like to have 240v split-phase output (mostly to allow longer AC cable runs with less voltage sag), but won't usually have 240v charging capabilities. 2x Victron multiplus (48/5000) would do that, but that's a lot of cost and weight. The EG4 6000xp would get me 240v, but I'd need a Chargeverter for the 120v charging option. Rumor of a MultiPlus III coming out that might over both 120/240v options - which would be great.

 

[HarryN]

It needs to fit into a 4X4 truck or loaded onto a boat to get to some of the sites.

That can be done - will need to be built in modules so that the pieces can be reasonably handled and lifted.