Fat Tuesday and a Night of Van Work

I wish you all a happy Fat Tuesday.   That’s about the only thing I still use my catholic upbringing for any more is knowing when Ash Wednesday (and it’s important predecessor) falls.   This past weekend I was telling myself I would go out tonight.   Find some music.   If it was the right crowd, maybe give out some beads.  But here it is, the night of the event and I am sitting in the pizza joint Barack Obama visited when he came to town a few years ago.   I am eating some pizza and getting ready to go work on the van.   I am hoping to finish wiring the 12 volt system as far as the fuse panel as well as fixing a mistake I made in the wiring and discovered as I was giving it the final look-over.   I asked The Wife if she would send me a few mardi gras themed selfies and I would pay her in beads in a few days…

Up here in the snowy white north, the sun doesn’t shine every day.   Sometimes we even go a stretch of grey days.  So not every day is going to provide my solar panels with sufficient light to replace an evening’s usage.  My concern then is I need to have enough battery capacity to run the typical number of days between sunshine.   The first step to figure out what you need is to figure out what you use.   Most every electronic item is marked with information about how much power it uses.  If you can’t find it marked on the appliance, often times a few google searches will get you in the ballpark.   Or, if you want an even more exact figure for household (110v) items, check into the Kill-a-watt meter from Amazon.    This meter allows you to exactly know how much power your device consumes.   Then, knowing how long you use it and a little bit of math, you will know how much of your battery it consumes.

The van is going to have two different electrical systems.  The first is twelve volt, straight off the batteries.   I want to get as much on this system as possible because it is the most efficient way to use my battery power.  This will provide all the cabin lighting.   I can run a 12 volt LCD TV.    

Tapping into the 12v port

Lots of things made for the camper market are made for this.   So for instance, my furnace is a twelve volt furnace.   If I can come up with the money for it  I can run a 12v refrigerator.   Other things which maybe you use in your house that have the brick in the cord, such as a wi-fi router can be made to work just by purchasing a different cord.   The 12v system will power the USB charge ports I will have at my table and at my bed.   Also, using 12v I can “maintain” on my laptop by plugging it into a USB port.  —Meaning I can’t charge my laptop battery while using it, but I can provide enough juice the battery doesn’t go down.   It would charge fully overnight when I am not using it.

Not everything is available or doesn't work well as low voltage.  For instance, there used to be one company that made a 12v microwave.  It was being marketed to truck drivers. Product reviews though were brutal.   It seemed to be solidly one star.  Everyone hated it for being slow.   It didn’t have enough power to pop corn.  Checking today, I planned to put the link in here, and I see the product is off the market.  

So for these appliances I will need the second electrical system at 110 volts.   It will have two ways to run this higher voltage.   The first, most obvious, is when I go someplace like a campground, I can just plugin.   But the second is by using a device called an inverter. (I chose the Tripp Lite APS1250)   Its job is to take the 12 volt direct current (DC) out of the battery and increasing it to 110 volts and at the same time turning it into alternating current (AC).  Suddenly the battery power becomes just like the power outlets you have  in your house.   The microwave plugs into this.  My laptop charger.   Keurig coffee pot.   Guitar amp.   Phillips Hue lights.  All that stuff plugs in just the same way as home.

The dash installed USB charge port

However, all this transforming and alternating comes at some cost.   The inverter, just by being turned on, consumes some power.   When it is actively powering an appliance it consumes even more power.   The model I picked out is roughly 85% efficient.   What this means in real numbers is my microwave, which is a 900 watt model, will require 1065 watts of battery power.   So that loss can add up.   Additionally, the inverter is rated at a specific size and get spendy as they get larger.   I went for one rated at 1500 watts, about as much as I can afford.   This is limiting because, not that I am inclined to use one, but for instance a hair dryer is 1500 watts.   You would think, inverter 1500, hair dryer 1500, no problem, right?   You forgot about the inefficiency loss.  Due to the inverter tax really I would be trying to use 1764 watts and the circuit breaker on the inverter would trip.

I broke my list down into two parts.   Required and desired.   Saying this and knowing still that “required” is sort of a fuzzy line as well.   Say it is ten below zero out and I have been running a number of sun-less days on my batteries.   Would I be willing to not watch TV, charge my phone or laptop,  and use minimal lights just so I could keep the furnace going another day?   Of course I would!

But lets say we are talking a normal night.   You can check out this spreadsheet.   I will keep it up as I figure out some more stuff.

https://docs.google.com/spreadsheets/d/1BjXjw-UiZQZ9chBMuuVJCJRoKufuBfYcFuhIbhRJAUY/edit?usp=sharing

But here is what the spreadsheet really boils down to.  Refrigerators are expensive.   I am using worst case scenario of a hot summer day and it is going to be using 40 watts when it is running and during a summer day it could be running 50% of the time.    Running that through some math (I will explain on some later day) I can convert this to amp/hours, I get 40 amp/hours (the math doesn’t usually come out that equal either)  So on a typical day I will be using 40, I have 250 total.  If my van only runs the fridge, no lights, no ceiling fans, nothing else, it will use up my batteries’ charge in six days.

The base I built for the
main switch.

Other stuff is seasonal.  I bet I don’t run the ceiling vents very much in the winter.   Maybe a touch if I am cooking something on the stove.   But I have them in the spreadsheet as running 3 hours a day year round.   I love my Phillips Hue strip lights though.   Those I might end up using at least three hours a night.   The lights themselves are not that much energy but to use them I have to be running a hub and a wireless network.   So those numbers have to be effectively added in.   …And yet, I am sitting here in the van and I know I have the ability to get a wi-fi signal, I am going to have my wifi network up.

Of course there are all sorts of back and forth on this and no way to come up with any definitive number.   Even here in the frozen wasteland I live, during the summertime it would be extremely rare to go six days with without a mostly sunny day.   One good sunny day and my batteries are back up to full charge.   And, during the wintertime, most of the day I will keep the interior temperature ~50.   It is only in the evenings for two or three hours when I might be sitting in here typing or watching a movie with The Wife. (She watches at home, I watch on my laptop but we start simultaneously and text back and forth)  During those times I will keep it comfortable.  The rest of the day, that refrigerator might only come on four times.

Side view of the main switch

In other news, I have been making some good progress on the van.   Last night I got the 12v power run up to the light switch by the side door.   One this is hooked up, the switch will allow me to turn on the main cabin lights.   Two flush mount LED ceiling fixtures will point down into the kitchen area and over the storage drawers.   I got the holes drilled in the floor for the toilet vents, and once that was done I got the last two pieces of the floor insulation glued down.   My plan is to let that get good and stuck down.   Then I will drill up from the bottom to cut through the insulation and subfloor.   Also, I got the main switch in place.  This is a 50amp rated switch installed right off the batteries.  I can use to completely shut off the 12v system.   

Up at the dash I installed a USB charger port.   When I started looking at this install I thought I would have to run a wire to the fuse panel, but once I looked into this more it seemed intimidating.   There was a live-all-the-time 12v port on the dash panel.   I certainly could have just plugged an adapter into that port but I don't really like those adapters.   It seems like they only last a year or so.   I am hoping this dedicated USB will last a lot longer.   What I did for the install was get in behind the 12v port and cut the wires there.   I spliced in a wire and ran it over to the USB.   With it being live all the time that means it has power regardless of the ignition key being on or off.

And the last thing I did was to install the 12v fuse panel.

All in all it was a great night’s work.

Here is my night's work and the mistake.   While I was
disappointed the wire coming off the switch crossed the
other wire before going into a 50a breaker, I should have
been reading the shunt install instructions. 

I remember the inverted triangle I learned about in high school english.   How you put all the really important stuff up at the top because you lose readers as the text continues.   That’s why I am sticking my mistake confession down here at the bottom.   I figure most of you are already gone by now!  The thing was I should have really known better.  I really like shopping on Amazon because of the product feedback system.   I feel like I have avoided some real losers by looking at the stars and reading what other people who bought the product though.   So when I found the digital power usage meter, I thought it was pretty cool and exactly what I need.   But why did it have only three stars?    In this meter’s case, it was really easy to tell.  Mixed in with all the 5’s were a whole bunch of people bitching about “Received product, didn’t work”  to which the seller was tirelessly replying “You wired it wrong.   It goes on the negative side of the battery, not the positive”  With a very few people sheepishly replying back “You were right!”   

Well, that was a month ago and I have trouble remembering what I had for lunch.   So last night when I was on a roll, wiring stuff up, I should have at least remembered this was a tricky item and looked at the installation instructions WHICH ARE VERY CLEAR.   But no, I was more interested in getting all the components in a straight line and being kind of bummed I had to cross two wires making it less aesthetically pleasing.   To me, logically everything should go on the plus side but logic is wrong in this case.