With unprecedented power requirements, Steve Hericks pushes the RV electrical envelope with a salvaged battery system from a Nissan Leaf electric car. Prepare yourself for inconceivable off-grid electrical possibilities, and amp hours beyond imagination.
For part two of Steve’s remarkable RV power system project, he installs a Nissan Leaf EV battery system into a 2000 Lance 1130 truck camper.
This is a bit like shoehorning a modern Porsche 911 engine into a Volkswagen Beetle (Type 1). Neither was designed for the other, and the results are almost hard to comprehend.
Before proceeding, be sure to read about Steve’s concept and required calculations in part one, “Future Shock: A Bold Vision For RV Power Systems”.
A Word of Caution: Extremely Dangerous Voltages
Most electric car batteries are constructed with 48-cells in series (48S) to output 360-volts nominal and over 400-volts fully-charged. This is lethal territory.
This information is provided for informational purposes only by a highly-trained professional with decades of electrical and battery experience. Do not attempt this project under any circumstances.
Nissan Leaf EV Batteries For RVs and Campers
by Steve Hericks
The Nissan Leaf is the most widely produced electric vehicle (EV) in the world. It also has the benefit that the battery pack is not liquid-cooled (like a Chevy Volt or Tesla).
Reconstructing the Nissan Leaf’s Battery Bank
The Nissan Leaf’s battery weighs 665-pounds and is a closed-steel container. Inside are 48 battery packs, connecting buss bars, and some control equipment. In each pack, measuring a little over 12-inches by 8-inches x 1-3/8-inches and weigh 8.5-pounds, are four cells wired; two in series and two in parallel making each pack 7.5-volts / 64-amp-hours.
The battery packs are very compact and convenient to reuse. A key driver in my choice to use Nissan Leaf batteries was that I could get them into a flat configuration to work in my project camper relatively easily.
I made a quick calculation to see how many of these batteries would be needed for my off-grid power requirements (detailed in part one).
1. Each battery pack has 7.5V x 64ah x 80% = .384kwh capacity
2. 13.077kwh (our energy needed)/.384kwh/battery = 34 battery packs
3. With 48-packs in the Leaf’s battery, we will have some spares.
The 12-Volt Challenges of Lithium Oxide Batteries
One key issue regarding using Leaf battery packs is that the packs cannot be disassembled into a usable cells below the pack’s level. For example, a 7.5-volt battery pack operates between 6.0-volts and 8.4-volts.
That raises an important question; Can you make a 12-volt compatible battery with a Nissan Leaf RV battery? Answer; No, you can’t. In fact, you can’t make a 12-volt battery with a Leaf battery or any lithium oxide technology.
The solution I developed is quite technical and required difficult modifications to the batteries that should not be attempted by anyone without the education, skills and extensive professional experience that I have been fortunate to obtain over the past four decades.
The completed battery has 35-packs (140-cells). 30-packs are connected in three series sets of 10 parallel packs making 6S20P. The remaining five packs have been opened and reconfigured to 1S4P, and then connected in parallel making 1S20P.
6S20P + 1S20P = 7S20P. The resulting battery bank has a capacity of 140-cells x 3.75-volts per cell (VPC) x 32Ah = 16.8kwh. The usable portion of this is 80% x 16.8kwh = 13.44kwh.
The simplest solution is 48-volts. Seven packs in series gets you 42.0-58.4V which typically works well with 48-volt inverters.
I settled on a 24-volt system because my power system will eventually be on a custom camper and on a former military truck that can wire directly to the 24-volt vehicle power. That was rigorous and quite possibly mind-bending. I hope you are still with me.