a little battery backup

As one of the Californians who is dependent upon the absolutely horrible PG&E corporation for electrical service, I have been experiencing extended black outs caused by PG&E intentionally de-energizing their extremely fragile grid.

One of the creature comforts of humanity that I miss most when the power is out, is indoor light. Since the mastery of fire, humans have had plenty of light in their caves; and now here I am, lacking in light, and shaming our cave dwelling progenitors. brutal.

Something needed to be done, and that something happened to involve collecting bits and bobs of electronics that are scattered about my place, and cobbling together a device that will bring light inside my cave… and keep the WeBoost 4G signal booster powered and functioning. :)

On October 27th, I woke up to a chilly morn, and got to work.

Build a base for some batteries

The power storage for this thingy is a pair of 12volt 35amphour deep cycle batteries. Originally, these batteries where purchased as a pair, one was intented to power a trolling motor, the other was supposed to store power for a small wireless repeater. Damn, it's a good thing I never built that repeater.

Add some walls

When the power is going to go out, charge everything that can be charged. Batteries, flashlight, power tools, everything. Be sure to charge the spare batteries for your tools as well. Sawing wood is far easier with power tools. :)

Add electronics

A 20Amp charge controller and a 400watt inverter were mounted to the side wall. Yea, yea, I know, a 400W inverter won't be able to power a lot of electronics. Well tough luck bub, this is what I have and I'm trying to avoid going shopping during a large scale power outage.

Make 1 cent washers

4 electricly conductive washers were needed, 4 cents were spent.

All wired up

The batteries where connected in parallel with 2 gauge battery cable left over from adding extra power to the van. oh damn, the van has a 750 Watt inverter now, and it can run a coffee maker :)

Add some strapping

A lumber delivery a few weeks ago, was held together with some thick strapping. A section of that strapping was used to secure the batteries in place, and then a longer piece of strapping was attached for use as a carrying strap.


That's your average 12V 100W panel. The attachment of the panel to the charge controller, is what I would consider to be the biggest failure of this build. Quickly detaching the panel at the cable connectors, will result in about 12 feet of cable still attached to the battery unit. Unacceptable! there should only be 10cm or so of cable attached to the unit when the panel is detached. Where do I file a bug report?

There is light in the cave!

This picture was made possible by a lamp connected to the inverter. Aside from providing light, the battery pack powered a WeBoost signal booster, and an internet connection was possible. It wasn't great; maybe 600-800Kbps down, 35-150kbps up. Dear Verizon, your coverage map is false advertising.

Now that there was light, I wanted just a bit more. Not light; there was enough of that. My craving was for something else that would bring normalcy to my cave. Music, please. The inverter has two power outlets and two USB ports rated at 3.1A. Into one of these USB ports went the phone for charging, and the other port was occupied by the Bluetooth Speaker. The internet speeds weren't great, but they were capable of streaming audio, and I had a hankerin for some commercial-free community radio. in the browser, and I was connected to the world.
Then I didn't like what they were playing so I switched to the Conan soundtrack :)

cheers, jezra