So I learned more about making life convenient this last off the grid Sunday.
A few notes:
Powering a laptop off of a lead acid battery lasted way longer than I thought it would. I wanted to put that to the test. It lasted way longer than a CFL bulb powered from an inverter so my choice to try powering it via DC from a boost converter paid off.
Cheap boost converters suck. The second I put mine under the load of the laptop its voltage dropped considerably. Some voltage drop should be expected from any power supply but my boost converter is rated to 400 watt. A 400 watt power supply should mean you should get 400 watts out of it before voltage drop becomes an issue. This is more of 400 watts until the thing explodes.
I don't think this is a problem of differing definitions for how something is rated. This is an issue of product scope. I think this is related to the fact that my booster doesn't seem to be voltage referencing. For this price bracket this honestly is the way it should work. I goofed.
So what it does is sends a square wave to a pair of transistors. The ratio of the width of one side of the wave to the other sets the voltage ratio between the capacitors at the end of the line and the source battery when there is no draw.
Here I was thinking that if I used my screw driver to adjust the pot and a multimeter to measure the voltage that if I set it to a read out of 19.5 volts that it would then sense if there was 19.5 volts on the capacitor end and pump in more energy when needed no matter what the load is doing or the battery (within reason). That is a thing proper boost converters do. Mine is still a useful device but not for my application. If you have constant load on your output you can supply it with a constant current with one of these. Or if you have something that doesn't care much about the voltage you give it (something mechanical) but you are nowhere in the neighborhood you can go from 12V to 60V.
In terms of my application that meant adjusting it so that it would under average load be at 19.4 volts but when nothing was hooked up to it it would be at 23 volts. This means that voltage regulators in the laptop could get excessively hot and my mother board sensed that this wasn't a reliable current source so it went into a mode where the battery will not charge and cpu performance is reduced. This means if you managed to get to 0% Li-Ion battery for some reason you cannot move the laptop without shutting down.
So that is the lesson of boost converters.
The next very simple lesson is to have extras of any connection parts. Simple and obvious lesson, but go to your automotive store so you have a few extra bullet terminals on hand.
The next lesson is a less than critical one but still a small point of life improvement for off the grid. Install an offline map system on your phone and while you are at it a full dictionary. "Oh, but I use physical maps in an emergency." Not every moment of off the grid is an emergency. You don't know you need a map till you do. And did you know that people are more forgetful in emergencies than in normal situations. Maps are handy. Basically anything you use in your normal life you want an off the grid version of it.
The next is a prepper basic. While we are talking about communication being down, two way multi-channel radios. I know that's super basic. The fact that I'm still doing basics is exactly why I'm doing this. I need to get my prepping in order and I'm not an expert. Off the grid Sundays helps me remember that I'm not an expert and that I have things I need to take care of that go outside of the typical apocolyptic fantacy.
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[–] carnold03 ago
Is your water heater electric or gas? Is the tank insulated? How much do you pay per kilowatt hour?
[–] bikergang_accountant [S] ago
Electric, insulated, 2.07 cents per kilo. The insulation wouldn't really matter on whether that kind of solar makes sense or not. It lowers the cost of bringing tap water to temperature.