Chapter 1 in a Four Part Series: Empowering Van Life: A Comprehensive Guide to Calculating Solar and Battery Power for Your Self-Converted Van

Venturing into the world of van life brings a sense of freedom, but with it comes the responsibility of ensuring a sustainable and reliable power source. In this guide, I'll explore the intricacies of determining solar and battery power needs for a self-converted van, making the dream of mobile living a reality. For myself, I knew I was always going to be chasing the sun, so and living as minimalistic a lifestyle as possible. This allowed me the freedom to not rely too heavily on my solar system, but I also wanted to never have to worry about running out of power, out on the open road, while mostly living a boondocking lifestyle. I chose to go without shore power or a DC to DC converter (charging my battery when I'm driving). I felt these were unnecessary as I would mostly be doing dispersed camping, oftentimes for 1-2 week stretches, so neither would do me much good, and I've never once regretted that decision.

The foundation of any solar and battery power system is a thorough understanding of your power requirements. Begin by creating a list of all devices you plan to use, noting their wattage and daily usage patterns. This comprehensive overview forms the basis for calculating the energy your system needs to generate and store. I want to try and make this process as simple as possible as I know it can be one of the most daunting aspects involved in building out a tiny home powered by solar. When I calculated what I thought my needed usage would be I made sure that it was more than ample enough to power everything, with power left over at the end of the day. This was a crucial calculation as I have now been able to add on other appliances such as a rice cooker and Starlink that I didn't have when I first started van life. And yet, I still have the power needed to run both without draining my battery. In fact, I rarely ever drop below 100% on my battery monitor (here is the monitor I use in addition to the monitor/power switch that came with my inverter).

One of the most important things to keep in mind is to run as much as you possibly can on a 12v system (DC) and minimal usage of the 120(AC), which is what a normal (prong) outlet is run off, and what the inverter powers. The more items consuming power from a 120 source, the more solar and battery you will need. 12 volt is the way to go! And you don't need a 220v system unless you are running a house dryer, full sized range or regular Air Conditioning in your rig. There are so many options out there in smaller sizes and less power draw for these appliances that you would never need a 220v system, so I will be referencing only a 120v system (sometimes referred to as 110, they are the same).

List of my power hungry items in my tiny home:

Here is a list of what I run off my system, which is powered by 420 watts of solar panel, a 200amp hour lithium ion LifeP04 battery, a 2000 watt inverter and 50amp MPPT charge controller. I think it's helpful to see what I actually power, and have for two years with my system to give you a real life example of what you may need for your off grid adventures.

• My 2,000 watt/12v inverter draws 1.5 amps so I had to convert that into watts. 1 amp equals 120 watts on a 120v/12v system, so 1.5 equals 180 watts, one of the higher consumption units I use. I never leave my inverter on when it's not actively charging something, and certainly don't leave it on overnight as that slow draw can drain your battery. If I want to watch tv at night and not have starlink and the inverter running, I will either download something on Netflix during the day, or even use my 50gb hotspot on occasion (if I have cell service) so as not to use extra power when the sun is down. It's simple little things like this that really help to conserve power, and the life of the battery. 

• I charge my gaming laptop throughout the day, which is also powered by my inverter using juice as well. My laptop is a 15" gaming computer so it draws approximately 45W. I typically have it on a charger and using it, along with the inverter when I'm painting as I will have a show or movie streaming in the background, this is probably the biggest daily draw on a regular basis, along with Starlink if I'm using it. 
  
   Mikee always wondering what I'm up too!

• I have Starlink which also requires 120 ac power, ie, the inverter to run, and it consumes 120-150 watts out of the box. I have seen talk of a DC converter for Starlink, that reduces the wattage to 36-72 watts, but I don't have that, although I need to look into it! I'm all about conserving power and making my system last as much as possible, so I will have to research this option further. Since Starlink also needs the inverter to run when powered with AC, but a DC option would eliminate that as well....hmmmmm.
  

• I have a mini, and I do mean Mini fridge, haha! Here is the one that I use and it runs off a 12v USB outlet, so the most minimal power usage out there. I'm not a big fan of cooking, at all, so having a really big fridge wasn't a priority for me. There are plenty of 12v options for fridges out there, so just do research and see how much wattage the one you want consumes, and see if it will work with your power system. I don't know the wattage on this as it isn't stated, but I have it plugged into the USB outlet all the time and it doesn't really impact my battery at all, the beauty of 12v outlets, low power consumption! 
  

 My tiny little fridge ~ it used to be white and I painted it pink to match the decor

• I have two LED 12v Panel lights that I use when I'm painting, even during the day, and at night I have a 12v led reading lamp that has a red light setting I have on all night, as yes, I am afraid of the dark, and if I don't have some source of light in my van when sleeping I end up with horrible night terrors...a lifelong affliction.
  

 My two 12v hardwired LED lights that light up my mobile art studio Perfectly!

• I of course charge my phone, watch, and other little electronics all off USB outlets throughout the day. These will have a minimal draw, but important to calculate if you have lots of them charging every day and you have a small solar power system. 

• My 12v rice cooker is one of the best buys I've ever gotten for the van, saves me sooooo much on not using propane for cooking! And as mentioned previously, since I don't like to cook, but love to eat, this makes cooking a breeze. I've had this cute little cooker for almost two years now and can cook 1-3 meals in it per day with my solar system, but that is usually in the summer months or if I have full sun hitting my solar panels in the winter. I typically only do two meals a day and avoid using it early in the morning, or evenings in the winter months, but middle of the day, works like a champ! I even cook raw beans (soaked overnight first) in this cooker all the time, which takes a couple hours and my system holds up, but, again, only if I have full sun and I use during the full daylight hours. It holds up to 4 cups of cooked rice, so perfect for one, maybe two people. This appliance draws the most power of anything in my van at 450 watts, but it is soooo worth it! 
  

• I also use this kettle mug to heat water for my morning coffee if I know my battery is fully charged and will have full sun during the day to charge it back up. In the summer months I don't even think twice about using it. It is 12v and uses a cigarette style outlet, be sure to have a couple of those in your van! It takes about 25-30 minutes to heat the water up hot enough for coffee, approximately 100 degrees, but worth it not to use the propane. As with any appliance that has a heating element it will take up more power, this mug uses 120 watts. It is 750 ml which is 3 cups, so perfect for a solo female van lifer like myself. There are lots of options out there for electric mugs and kettles, I like this one because of the size makes it easy to store. I've also seen collapsible kettles, but not sure of the wattage usage, so be sure to check as they can vary wildly from one brand to the next. 
   

• I even have a tiny portable heater that I will use on occasion to just warm my work space when I'm painting, or working on the computer, and don't want to use my propane Buddy Heater. This is again one of those units I only use for a short amount of time and know that I'm going to have full sun all day hitting the van. This works because if there is full sun, and it's a wee bit chilly out the sun will warm the van up pretty quickly so I only have to use the heater for a short amount of time. This little boost of heat costs me 500 watts of power, yikes! But, my system will power it for the minimal bit of usage I need it to, so it's a handy little unit to have around, that doesn't take up much space, and puts out the right amount of heat sitting on my table as I'm working. 
  

 Mini tabletop space heater I use to warm my hands when painting

• In the summers I have a little tabletop air cooler fan that I can put water in for an extra shot of cool air in addition to my Maxx Air Fan, and because it's usually full sun and long days when I'm using it this doesn't make any impact on my battery. This is another unit that doesn't state the wattage, but again, I only use it if it is really hot out, which I try to avoid any temps over 80-85 degrees for both my cat Mikee and I's comfort. 
  

•  Speaking of the Maxx Air Fan, which I use quite a lot, since I'm almost always in a place with lots of sun, it's an absolute necessity for van life! It's a hardwired 12v fan, I have the manual version, I really don't need the automatic, just something to break, haha. I mean, I only live in a 60 sq ft house, I'm not that lazy! It uses approximately 50 watts, but usually only running when there's lots of sun out charging up that battery! 
  

My Maxx Air Fan keeping my space nice and cool!

Once you've calculated the appliances, etc. you will be using, and the wattage they consume, create a chart, such as the one below, to help you determine how many total watt hours you will need in 24 hours. 

Add up the totals for the two numbered columns (wattage & time) by multiplying the run wattage by time running. If it's minutes, do it as a percentage of 1 hour (ie. 30 mins = .5 hrs). Then calculate watts/volts = amps. So add up all your watts you will be using in a day, divide it by 120(volts) and this will give you amp hours neeed to determine what size battery you need. Then double the amp hours of that battery for the watts needed for your solar panels to charge said battery. Easy Peasy!

The easiest rule to determine how many watts in solar panels you need in relation to how many amp hours of battery is a 2:1 ratio. For instance I have 420 watts of solar panel and 200ah of battery. So, for every 100ah of battery you need 200watts in solar panels. If you have too much solar coming into a smaller battery, it will just be wasted and not utilized, and if you don't have enough solar it will not charge your batteries fully. I've found the 2:1 ratio works perfect, and found it recommended repeatedly in my internet research when I was figuring out my system.

And I only recommend a LifeP04 Lithium ion battery for the following reasons. Yes, they are more expensive, but the cost far outweighs the loss benefit of lesser power storage and failure of a regular lead acid battery if drained past 50%. I have accidentally drained my battery several times, with no adverse effects. I wouldn't recommend doing that obviously, But, sometimes it does happen. The LifeP04 battery is also the safest battery there is, which is always something to take into consideration with any part of your van build, safety first. The cycle of life of a LifeP04 battery is also so much better than other batteries, up to 5,000 charges over it's lifetime, versus a lead acid battery only up to 500 charges. They are also considerably lighter which is one of the biggest concerns when building out a van, so by far the LifeP04 battery is the way to go!

My underbed storage area where the battery and components live

The next step once I understood how much power I would need, and that only one battery was necessary, was where I was going to set up my electrical grid in my van. It's important to have this phase all figured out early on, so that you can work on other parts of the build first, but be aware of exactly where, and how much space you will need for the system. This was actually pretty easy, since I had been brainstorming my actual layout for months. I knew I was going to build out the van so that my single/twin size bed would go sideways across the van, to maximize the rest of the van for living quarters and my art studio. I'm 5'8" and with a simple buildout with the insulation and paneling included, I ended up with 6'2" of leg room, plenty of space for me to stretch out. Underneath of bed area, accessed from the two rear doors, was set up as all storage and where my electrical system now resides. I opted to put the battery next to the wheel well on the back passenger side of the van. The inverter is mounted above the top of the wheel well, along with the MPPT charge controller, fuse box, etc. and secured to the van frame itself. This has worked out perfectly so far and allows me easy access to my electrical system whenever needed. The base of the bed is set at 36" which gives me plenty of room to reach any part of the power system I need.

Easy access to the entire system from the double back doors, under the bed

Now that I've given you an overview on my system, calculating the amount of power you will need from solar and your battery storage, and preplanning placement of your system, it's time to delve into the next chapter, which will discuss in detail the actual components I ended up selecting, from the panels to the MPPT charge controller. This will all be discussed in an upcoming blog post, so be sure to sign up for my newsletter I send out once a week with all blog updates. I hope I covered everything in this phase of building a simple solar power system, but, please feel free to reach out to me with any questions you have via comments or email (use the contact tab). Thank you for following along and stay tuned for the next chapter in creating your off-grid solar powered system for your tiny home!

TIP:  is to have small battery banks and have them fully charged at all times so that if you are in a forested area, rainy overcast place for too long, you at least have options to charge your phones as back up, especially at night. I try to avoid both of these situations, but it's always good to have a back up plan. Or even, get a larger portable battery bank such as a Bluetti or Jackery. I don't have either and haven't needed the backup, but if you know you are going to frequently be in places for more than a couple days that won't have any sun, it might be a good
idea to have that backup in place.

Here are links to the main components I used for my solar system that I've had for two years and never a single issue. I will share more links for other products in my forthcoming detailed blog posts. To see all of my appliances I use visit my Amazon Storefront and/or click on any of the images above for that particular item.