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Joule Case for Food Trucks - FAQ


“Diesel doesn’t pair well with coffee.”

Matt Larson, Owner
Relationships Coffee, Boise Idaho

Food Truck Battery Systems - FAQ


1) Why should I replace my generator with a Joule Case?

Replacing your generator with a Joule Case system frees you from the cost, noise, and smell of a traditional generator. Although the upfront cost is higher, it is more than offset by the lower lifetime cost by eliminating the high cost of gasoline or propane. A battery system also allows you to provide a better customer experience by eliminating the noise that a generator produces.

2) I currently use a Honda/Onan/other generator. What battery system would be the best fit for me?

If you are already using a generator, tell us the wattage rating and how often you need to refuel. We can help you design a system that will fit your needs by matching (or exceeding) the wattage of the generator and sizing the battery bank to match your typical gas or propane consumption. We love helping customers transition to clean, quiet solutions. Please reach out to the Joule Case team through our website (, emailing us at [email protected], or by calling (888) 200-5114 and we can help you design a battery solution that can save you money and provide a better experience for your customers.

3) Can you charge and use the system at the same time? 

You can always use your Joule Case while charging via solar by connecting a Joule Case Solar Charge Controller. 

You can also charge via ground power while using if you use the Joule Case Fast Charger. A fast charger is $300 and also reduces charge time dramatically (see below). 

If you are using only the P1200 Control Module you can either charge your batteries or discharge them, but not both at the same time.

4) How long will my system take to charge? 

The recharge time for your system will depend on the size of the battery bank and the size of your charger. A Joule Case Li4k Battery Station will take 28 hours to fully charge from 0-100% from a wall outlet but only 6 hours with a Joule Case 50 A Fast Charger. For systems that require more than a single Li4k Battery Station we will help you specify a charger that provides close to 50 A per battery station. 

5) If I wanted to boost my run time by adding solar panels to the roof roughly how much of an impact could I expect? 

The impact of solar panels depends on several different variables such as the number and wattage of solar panels, the area that your truck is operating in, how much sun your solar array sees, and the time of day that you are operating. For our heaviest users a solar array adds 1-2 hours to their operating time. For smaller energy needs the extra operating time would be much larger.

6) Are tax credits or rebates available for battery systems?

There are a variety of tax incentives available for renewable energy.  For example, there is a federal tax credit of 26% of the cost of installing a rooftop solar array, including batteries if they are installed concurrently. The National Renewable Energy Laboratory has put together a great summary of the program which can be found here. There may also be state incentives available as well. The Database of State Incentives for Renewables & Efficiency is a great resource to start your search and can be found at  Please consult a tax professional for details on how you can take advantage of these programs.    

7) Where can I put the battery system? Can it be placed on the tongue of the trailer in an enclosed case?  

Most customers place the battery modules in the generator compartment of the truck or trailer, but the battery modules can be placed outside. If placed outside the battery modules are rated for temperatures ranging from 0 to 45 C (32 - 113 F). The batteries have weathered many elements (including a 10-day trip to burning man) but to maximize the battery life we do recommend placing them in an enclosed and vented box.

8) Battery Capacity - How many batteries do I need? Do I need a battery stack dedicated to my larger appliances? What about loads that cause a power surge like a blender or coffee grinder?

Some customers are able to power small loads with a portable power stack (PPS). For example, a small 500 PPS would easily operate your POS system, lights, and other small loads. But most customers need a larger system with the capability to handle loads that cause surges and potentially require 240 split phase power. For these types of solutions please reach out to the Joule Case team through our website, at [email protected], or by calling (888) 200-5114. If you currently use a gas or propane generator for your truck or trailer, we can help you design a battery solution that can replace it, save you money, and provide a cleaner, quieter experience for your customers.

9) I am familiar with my gas generator, but what do all these other terms mean?

Portable Power Stack - A Joule Case Portable Power stack is the combination of a Joule Case Control Module, which contains an inverter and a charger, and at least one battery module.

Inverter - The inverter is the component that converts the DC of the battery into AC for use by the loads in your truck or trailer. 

Watts - Watts (or Kilowatts) are a unit of power transfer. This is a measure of how much power you are drawing at a given time. You will need to size your inverter to ensure that it can handle your max surge power. 

Watt-Hours - Watt-hours (or Kilowatt-hours) are a unit of energy capacity. This is a measure of how much energy you have stored. Your system will need to be sized to provide enough energy for your entire shift.

Amps - Amps are a measure of how much current is flowing from a power source to the load. Your electrical system needs to be sized for the number of amps that each wire needs to carry.

Amp-hours - Amp-hours are another way to measure battery capacity. They make it easy to compare how much time a battery can provide at a given amp draw. (Please note that Amp-hour comparisons do not work when comparing different battery voltages. In that case, please compare watt-hours.)

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