Inverter/Charging for Food Truck

thetortoise

New Member
Hi folks,
I'm building a battery system for a food truck/trailer. I'm waffling on my inverter/charger size. I'm having trouble finding a clear answer on a few things so maybe you can answer these questions for me.

System info
Energy requirements: 2200w continuous (1700w actual X 1.25) and 4700w peak. Daily consumption is 9.2kw
Battery: 24v 13.3kw Lifepo4 bank
Electrical Appliances: 3 fridge/freezers, water pump, food processor, rice cooker, range hood

1) My trailer will be parked for charging every night for 10 hours. When choosing the amperage of my battery charger, do I only care that it's big enough to re-charge my batteries in this timeframe? Or is there a minimum charger amperage for a battery capacity ratio (I've seen 30% thrown around) that is optimal for Lifepo4 battery health? I think I'd be fine with a 50amp charger to suit my needs.

2) I'm getting conflicting messaging on how to size my inverter in relation to peak rating. Some say to use your peak watts as the base inverter wattage and some say to make use of the inverter peak rating. My understanding is that if the inverter has a sufficient surge rating and it lasts for several seconds (5+) then I'm fine to match my peak watts to the inverter peak rating. So in my case, if I use an inverter with 3000w continuous and a peak rating of 6000w for 20 seconds then I'm set. I'm wondering if there are reasonable risks to this situation that I'm not anticipating.

Thanks for your input!
Cheers,
Kyle
 

mike95490

Solar Enthusiast
I don't like to load inverters past 70% of continuous rating at ambient temp. You might have to look hard for the proper chart/graph that shows the data for your inverters
 

Boondock Saint

Solar Addict
2) I'm getting conflicting messaging on how to size my inverter in relation to peak rating. Some say to use your peak watts as the base inverter wattage and some say to make use of the inverter peak rating. My understanding is that if the inverter has a sufficient surge rating and it lasts for several seconds (5+) then I'm fine to match my peak watts to the inverter peak rating. So in my case, if I use an inverter with 3000w continuous and a peak rating of 6000w for 20 seconds then I'm set. I'm wondering if there are reasonable risks to this situation that I'm not anticipating.

Who suggested you to use one inverter?

By two inverters and plan to run them at around 40% estimated average load each. They'll stay cooler and last longer, and if you get a SHTF moment instead of being hard down, you can quickly put all the load over the the working inverter and it still be 100% operational as very short term solution till you get the replacement. Food trucks are hostile environments, you'll need to keep these babies clean and cool.
 

time2roll

Photon Sorcerer
I would have two 3 kW inverters and 15 kW battery with 1.5kW charging probably split between two chargers.
I would not be going with the very minimum for a business.
 

thetortoise

New Member
Yea that's a good point on using the two inverters. My failsafe was just going to be a backup generator (so like a normal food truck) so if any part of the system fails or isn't operating normally I'd bypass the battery system entirely with the generator (not IF but probably when..). I do agree it's a good idea to spread the load between two inverters on top of this. The double R rule: redundancy and redundancy.

I was considering the Sigineer 3000 Watt 24 Volt Inverter/Charger. Doesn't say anything about whether they can be stacked but I'm waiting on a reply from the technical team now. They have a 3000w all-in-one that is stackable so that could be a good route as well. The all-in-one would provide a more complete backup of most of the system as well..

I do plan to have 800watts of solar on the roof so in the summertime I'll get a couple of kW out of that (sunny days = busier days).

We'll be doing sushi and dumplings so we won't be a hot greasy mess like a lot of trucks. No deep fryer or griddle. Also lots of windows so good airflow.

Thanks I needed a push in the right direction and that was helpful.
 

Cheap 4-life

Solar Enthusiast
I also have a large food truck. I use a generator that barely uses any gas. Cost $1000. Its 4900w surge. Push button start. It’s great. Why inverters and batteries?
 

thetortoise

New Member
I also have a large food truck. I use a generator that barely uses any gas. Cost $1000. Its 4900w surge. Push button start. It’s great. Why inverters and batteries?
Well, it definitely wasn't a question of simplicity or even economics. The reasoning came down to:
1) It can't be loud. Both for some of our parking spots and for my partner (ie wife/boss). The quiet generators with a rating I need are already at least $3k-$5k up here in Canada. The battery system with solar will be $6000. If you factor in $1k in generator gas per year it isn't that much worse.
2) Branding/ethos - we are promoting sustainability through packaging, food sourcing, and how we power the trailer. It has made us more competitive for specific financing programs in our region.
3) We're both just really excited to build the battery/solar system
 

Forbisher

Փփքխմպձժճֆըվմ
3) We're both just really excited to build the battery/solar system
I thought you were charging batteries with grid power overnight?
What is the solar part?

You can charge LFP at 0.5C so 50A would be way under that.
There is no minimum charging needed.
 

thetortoise

New Member
I thought you were charging batteries with grid power overnight?
What is the solar part?

You can charge LFP at 0.5C so 50A would be way under that.
There is no minimum charging needed.
The solar will only be around 800w-1000w on the roof of the trailer so we'll be primarily charging via grid power. The solar is mostly to make it a tiny bit greener while our grid moves from coal to wind.

Thanks yea that makes sense to me that no minimum charging is required for lithium.
 

Forbisher

Փփքխմպձժճֆըվմ
The solar will only be around 800w-1000w on the roof of the trailer so we'll be primarily charging via grid power. The solar is mostly to make it a tiny bit greener while our grid moves from coal to wind.

Thanks yea that makes sense to me that no minimum charging is required for lithium.
1000w panels x 6 Sun Hours a day is 6Kw a day.
What's the pay off on that?
Panels. Mounts. SCC. Wire.

On grid power at 12 cents Kwh you could charge at 100A or more.
What's the huge battery Ah?
 

thetortoise

New Member
1000w panels x 6 Sun Hours a day is 6Kw a day.
What's the pay off on that?
Panels. Mounts. SCC. Wire.

On grid power at 12 cents Kwh you could charge at 100A or more.
What's the huge battery Ah?
Well the payoff isn't great because I'd be charging during off-peak hours, so it's only 9 cents/Kwh. The 1000w system would save me about $60 per summer. Total system cost would be around $1300 (if I go with an all-in-one)

The battery system will be 544ah at 24v
 
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