There is no food-truck forum. The people wiring food trailers ask on the electricians' boards, the people fitting out grooming vans ask on the groomers' board, detailers ask on the detailing board and service-truck owners ask on the truck boards, and none of them can see the others' answers. The questions are the same question: how much battery, what inverter, how do I charge it, and how do I keep it from killing the truck's start battery.
This guide is the shared answer. The worked numbers are examples; your nameplates are the real ones.
Start with the loads, in watt-hours per day
Every appliance has a nameplate wattage. Multiply by the hours it actually runs, not the hours it is switched on, and add them up. Refrigeration cycles, so a fridge marked 300 watts that runs a third of the time is 100 watts average.
Example, a small food truck overnight: a reach-in fridge and a chest freezer, together averaging perhaps 250 watts through a warm night, for 12 hours, is 3,000 watt-hours. That is the number that decides the battery.
Example, a coffee van during service: a 2,850 watt espresso machine, a grinder, a small water heater and a fridge do not run flat out, but the machine's heating element sets the peak, and the peak sets the inverter.
Two figures come out: daily watt-hours, which sizes the battery, and peak watts, which sizes the inverter.
Why mobile businesses go to 24 or 48 volts
A 3,000 watt load at 12 volts is 250 amps through the cables. At 24 volts it is 125; at 48, 63. Above about 2,000 watts of continuous load, 12 volt systems become an exercise in enormous cable and hot connections. The boards that have done it settle on 24 volts for a 3,000 watt system and 48 volts for 5,000, and that matches what the equipment is designed for.
| Business | Peak load | System voltage | Inverter-charger |
|---|---|---|---|
| Grooming van, one dryer plus clippers and lights | 2,000 to 3,000 W with a dryer surge | 24 V | MultiPlus-II 24/3000 |
| Food truck, refrigeration plus small appliances | around 3,000 W | 24 V | MultiPlus-II 24/3000 |
| Coffee van with a commercial espresso machine | 4,000 to 5,000 W | 48 V | MultiPlus-II 48/5000 |
| Food truck with an electric griddle or fryer | 5,000 W and up, often generator-assisted | 48 V | MultiPlus-II 48/5000 with PowerAssist |
| Service body, tools and battery chargers, occasional 1,500 W tool | 2,000 to 3,000 W | 12 V from the truck | see the service-body section |
The grooming-van point deserves emphasis because it is the failure the groomers describe: a high-velocity dryer draws a surge at start-up well above its running figure, and a cheap inverter sized to the running figure trips or dies. The MultiPlus-II's peak rating is substantially above its continuous rating precisely for motor starts.
The battery
Take the daily watt-hours, divide by the system voltage, and divide by about 0.85 for inverter losses and margin. The 3,000 watt-hour overnight food-truck example at 24 volts is roughly 150 amp-hours of lithium; at 48 volts, 75.
The Victron NG lithium range is built in 24 and 48 volt modules, 100 to 300 amp-hours at 25.6 volts and 100 amp-hours at 51.2, with cell-level monitoring and a BMS that talks to the inverter-charger so it stops charging or discharging before the cells are at risk. Lithium's advantage for a business is that you can use most of the capacity every day for years; lead-acid sized for the same job is twice the weight and a fraction of the life.
Fusing, which is not optional
A lithium bank can deliver over ten thousand amps into a short. The fuse at the bank must be a Class T with an interrupt rating to match, and the Lynx Class-T Power In is the busbar that holds it, with a Lynx Distributor fusing each branch downstream. Our sailboat lithium fusing guide explains the layering; it applies unchanged to a truck.
Charging: three sources, in order of importance
1. Shore power, wherever you park. The MultiPlus-II's charger refills the bank from a 30 amp outlet overnight, and its transfer switch passes shore power straight through to your appliances while it does. A 30 amp cord with the twist-lock generator end and the standard RV receptacle covers a commissary hookup or a generator. The inlet, the transfer arrangement and the AC wiring on a food truck are subject to electrical code and health inspection, and that part belongs to a licensed electrician; the Mike Holt threads exist because that is who is asked. Give them the inverter-charger's manual and they will know what to do with it.
2. A generator, made smaller. The MultiPlus-II's PowerAssist adds battery power to a limited AC source, so a 2,000 watt generator plus the inverter can run a 4,000 watt peak. For a food truck that means a smaller, quieter generator than the load alone would demand, running only at lunch rather than all day.
3. Solar on the roof. A truck roof carries 400 to 800 watts of panel, which through a SmartSolar MPPT covers refrigeration on a sunny day and cuts the shore charge needed overnight. It rarely covers cooking. Size it as a supplement.
The service-body question: live with the truck off, without draining the start battery
Mobile mechanics and detailers ask a different version: an inverter in the service body that runs tool chargers and a 1,500 watt tool with the engine off, that cannot flatten the start batteries.
The answer is a separate house battery, charged from the truck through a DC-DC charger, with the inverter on the house battery only.
- The Orion XS charges the house battery at up to 50 amps while driving and, because it detects engine running, stops when the engine is off. The start batteries are never connected to the inverter's load.
- The Phoenix Inverter 12/3000 runs the tools from the house battery. If the truck also plugs in at the shop overnight, the MultiPlus 12/3000 replaces it and adds the charger and transfer switch.
- A Smart BatteryProtect on the house battery's DC loads disconnects them at a set voltage, so a charger left on overnight cannot take the house battery below where it can recover.
A detailer asking whether a deep-cycle battery and inverter can replace the generator for a pressure washer, buffer and vacuum gets a qualified yes: the buffer and vacuum, easily; the pressure washer's motor start is the peak that decides the inverter, and a 3,000 VA unit with a lithium house battery handles a typical electric washer. The generator stays for the day you run everything at once.
Monitoring for a business
A Cerbo GX ties the inverter-charger, MPPT and battery together and puts the whole system on your phone from anywhere, which for a truck that sits overnight with a freezer full of stock is the difference between an alert at 2 am and a loss at 6. On a smaller system, a SmartShunt gives the state of charge that voltage alone will not.
Where to start
Send us the nameplate list, how many hours you serve, where you park overnight and whether you have a generator. We will size the bank and the inverter-charger from your numbers, and tell you which parts belong to your electrician. Our MultiPlus-II sizing guide covers the 12 versus 24 versus 48 volt decision in more depth. Everything ships from Upland, California.