This type of conversion would not have been possible without an adequate battery bank.
As we talked with Mona, at the beginning of this journey, we realized that her van conversion needed to be all electric, powered by solar. This led to planning how this could and would be done, as the construction of the conversion took place.
We didn’t want to add propane tanks and plumbing, and didn’t want to tap into the gasoline tank. We planned on having a lot of powerful electric appliances in the van including:
Battery bank with room for one more battery
1) 12V 2000W pure sine inverter
2) 120VAC 15A 7gal electric water heater
3) 12V high efficiency rooftop air conditioner
4) 12V high efficiency Indel B CR-130 refrigerator
5) lots of interior and exterior LED lights
6) 12V ventilation fans, and water pumps
The key to the design of an all electric van conversion is the energy storage system, the batteries. First, we need to know the amount of power we expect to use and how we expect to use it, then we can design the battery bank because we designed the van with such a high reliance on electricity, we needed to have very highly reliabile batteries. We have 6 years experience with the Battle Born brand of LiFePO4 batteries, with a 100% track record of reliability, so we chose to use their batteries.
We started with two of the 100AH, 12V batteries giving us 2.5KWH of usable energy storage. This is the minimum size battery bank we calculated as necessary. We anticipated that Mona may need more storage in the future, so we left room to add two more batteries later. Unlike lead acid batteries, you can mix Battle Born batteries that are different ages (to a certain extent, there are limits).
Some of the key reasons we chose LiFePO4 and Battle Born brand are:
1) We needed a battery for an off-grid system that would be highly used every day. LiFePO4 batteries are very good for this application because:
a) They are not susceptible to aging when
in a partial state-of-charge (SOC).
b) They can be cycled 3000-8000 times before they wear out. This translates to 10+ years of heavy daily usage.
c) They can handle very fast charging, excellent for large solar arrays.
d) They can handle large discharge currents, excellent for our 2000W inverter.
2) They have a 10 year warranty from a company that is known to stand behind its warranty
3) They are premium, American made batteries, of the highest quality.
4) The Battery Management System built into each battery provides complete protection for the battery.
5) They can be mounted in any position, and
do not need any venting.
6) They are completely maintenance free
This last point, maintenance free, is important because we planned on building the batteries into a secure battery box that is mounted above a rear fender well. We then walled them in, which allowed us to have a large storage area where we did not have to worry about stuff getting jammed into the batteries. If we had to remove all the stored stuff and wall to check the batteries every so often, it would have been a real pain the screwdriver.
We have a real time, Bluetooth and WiFi battery monitor system in place to keep track of every aspect of the batteries, including state-of-charge (SOC), run-time-remaining (RTR), voltage, current in and out, temperature, watt-
hours and amp-hours meters and data logging of all these parameters.
Mona can now go boon docking in comfort, and without worry that she will run out of power, because she has a customized van with a heart.