Oh well … It turns out almost everything I did on my first attempt at going solar was wrong.
Wrong wire sizes, wrong lengths, wrong assumptions about how a bank of batteries should be wired … All of which made for a lot of possible failures.
Overestimating how much power I would actually be using … And more than a little good luck keeping any of those failures from happening!
So … Back to the drawing board …
The first “order of business” was to get a real metering system installed … It was time to find out what was really going on with the batteries.
I needed a “gas gauge” I could trust.
The Trimetric meters from Bogart Engineering are highly recommended by a lot of folks. … I decided to try the 2025 RV model for the project.
The 2025 is a very neat device that keeps track of the power in Amps going in to and out of the batteries … A quick look will tell you the voltage. Press a button and you will see how much power is going into or out of the batteries. Press the button again and the meter will tell you the batteries are 87% full (… Or 18% full … It might be time to start thinking about worrying … Soon!).
In any case … More information than I could have hoped for!
The folks from Bogart Engineering have designed the meters to do a lot more … But those three things were going to answer a lot of my questions … And keep me out of trouble … For a little while at least!
Adding the meters to my “rigs” was going to take some rewiring … and some math … More on that later.
Since I was going to have to get in and do some rewiring to install the meters it made sense to go in and fix as many of my wiring mistakes as possible … My good luck was only going to get me so far!
If you’ve been following along since the beginning you may remember my first big battery powered show having some yellow “warning” LEDs flashing on one of the inverters. The band had not gotten any louder … But something had changed … It took over a year to figure out what had happened … the power in the batteries was not getting to the inverter.
Resistance was “robbing” the system of power.
The wire I was using was too small and too long for the current that was trying to get from the batteries to the inverter … Causing a voltage drop … Causing the inverter to “ask for more power from the batteries … Causing the resistance to go up …causing more voltage drop … Causing …
It was a good thing I pulled the amplifier from one inverter and plugged it into the other inverter when I did … Or that show might have been the last!
My common sense approach was not helping at all … Luck … On the other hand … Was!
When using batteries to power something you do not want to waste anything. Leaving a 60 watt light bulb on overnight will “eat up” a lot of your battery reserve. It can be done … You just need more batteries … And solar panels to make it happen.
A little common sense would tell you … If you do not need it … Turn it off!
Common sense probably won’t tell you how much power will be wasted by using the wrong wire. Too small or too long of a wire could waste as much power as that 60 watt light bulb.
When using DC power a good “rule of thumb” is always use the largest, shortest wire you can.
So … I bought a bunch of larger wire to replace the stuff I had started the project with, ordered some meters, shunts, heavy duty buss bars, fuse blocks, fuses, lugs, heat shrink tubing … and my new favorite tool … A hand held crimper capable of hand crimping up to # 4/0 cable!
I wanted my systems to perform as well as they could … The solar powered equivalent of a finely tuned sports car as it were.
I’m afraid I’m going to be seeing lots of 4/0 in the near future …