Category: Home Power

Two Letters Re: Thermoelectric Generators for Wood and Coal Stoves

James, To follow up on an earlier letter and your reply, Thermoelectric Generators (TEGs) work by generating power from the movement of heat from the hot side to the cold side of a dissimilar metal junction. An important consideration is that TEGs can become heat saturated or worse if you can melt your TEG, so don’t just throw it in the middle of a fire! I followed a design from “The Boy Electrician” by Alfred P Morgan 1913. It uses German silver wire and copper wire with hammered junctions, there are better combinations but this was easy to get. It …


Letter Re: Thermoelectric Generators for Wood and Coal Stoves

Hello You folks do an outstanding job of informing those who want to learn! I was just wondering if there was information about homemade thermocouples out there. I was watching my woodburner last night and it has one of those little fans sitting on top that start to spin when they get hot and was wondering if I could find plans to build a bigger version of the thermocouple. I envision something about the size of a briefcase . In a grid down situation this would be set on top the woodburner that would be going for heat and cooking …


Three Letters Re: Some Real Life Battery Data

Dear Jim, I have some comments on the comments regarding batteries: Nickel Iron (Ni-Fe) batteries do indeed have very long shelf and operating lives. But they also have some significant downsides. Similar to NiMH cells (they are not the same) they have a very high self-discharge rate. In some cases approaching 40% per month. If you have a large solar array that is always making excess power, you are all set. But if you are charging with a generator, and have a large bank to keep power available for extended periods, you will waste a lot of the generator’s output …


Letter Re: Some Real Life Battery Data

Jim, I have been following with interest over the last several days this thread on batteries and feel I have some information to share. To begin with, the only solution to a long term lead-acid battery bank is to make your own cells. Lead has a perpetual shelf life and oxidizes very little over time if protected. Contrary to the confusion established by the battery manufacturer cartels, both plates begin as simply pure lead (Pb). It is only after the initial charge is applied that the positive plate changes chemically due to the sulfur ion action. While home made cells …


Letter Re: Some Real Life Battery Data

Hello Jim – I took interest in your response to the post by Steven J S “Letter Re: Some Real Life Battery Data” and the concept of storing “dry batteries”. From my long and intensive research on this, you are absolutely correct. Finding a true dry battery (one that was not flooded and then emptied) is nearly impossible. Perhaps some other SurvivalBlog readers can provide some help on this topic, but I have found that in order to truly get a dry battery – one that has never been flooded with acid – one would almost have to work at …


Letter Re: Some Real World Battery Life Data

Hi Jim, There are batteries becoming widely available these days with the lithium/iron-phosphate chemistry (different than the lithium/cobalt chemistry in laptop batteries). These lithium iron phosphate (LiFePO4, or LFP) cells were first used in Dewalt brand lithium power tools. The main advantages are a vastly improved cycle life (2,000 – 7,000 cycles versus 500-800 for lead acid and 500-1000 for NiMH), high discharge current closer to lead acid, better deep-cycling performance, they won’t explode like laptop batteries and need no maintenance, venting or caustic chemical refills and they operate at almost 100% efficiency. If you topped these batteries off once …


Letter Re: Some Real World Battery Life Data

Jim, The recent article by ‘Cactus Jim’ got me thinking about a type of battery rarely mentioned, the ‘dry-charged’ lead acid, where the end-user fills the battery with acid after purchase. Initial impression is that this type, if kept sealed in a temperature and humidity stable environment, could last indefinitely, only being flooded and charged when needed. Battery acid is stable and does not deteriorate if kept sealed. Our local NAPA auto parts store stocks small (motorcycle/garden tractor) units and will special order most any size 12v battery. Price is the same as for the equivalent wet-charged units except the …


Some Real World Battery Life Data, by Cactus Jim

Battery technology has come a long way in the last 10 years since Y2K. Back in the late 1990s, I stocked various types and brands of batteries for long term storage or use. Batteries ranged from store purchased alkaline, rechargeable alkalines, NiCd, generic deep cycle marine batteries, gel-cell sealed lead acid, lithium and even the ubiquitous flooded lead acid Trojan T-105 floor scrubber batteries. I wrote dates on all the batteries and rechargeable batteries had logs kept of use and maintenance. In most cases enough batteries were purchased to allow for a reasonable statistical sampling, thus providing a real level …


Three Letters Re: Lessons Learned From an Ice Storm

Dear Editor: With regards to the battery powered carbon monoxide (CO) detector, I just want to second that. When my family went through the Nov. 2007 ice storm that took out the power to half of Oklahoma, we were running off our generator for two days. The first night I put it outside, but close to the house to help shelter it from winds. Our CO detector went off in the middle of the night. We ended up having the fire department come out and check things. It was determined that the CO came in through either the dryer vent, …


Two Letters Re: Lessons Learned from the Oklahoma Ice Storm of 2010

Dear Editor: The Oklahoma Ice Storm of 2010 is now melting away and as usual there were lessons learned.   Many of these should have been “known” before but we are never as prepared as we should be.  In that vein I am going to rehash several things that went right, a few that went wrong, and others that we can improve on the next time that “life as usual” is not. First, the setting: I live in Southwestern Oklahoma and have been here for almost three years.  About January 22nd we started getting word of an impending ice/snow storm scheduled …


Lessons Learned From an Ice Storm, by G. in the Zarks

While watching the local weather over the last few days, it has become apparent that a winter storm is heading for our part of the world, bringing with it the distinct possibility of not just snow, but significant amounts of ice. As I pondered this, it brought to mind our recent experiences with ice storms over the last few years, most notably in January 2007. I thought some of our “lessons learned” were worth sharing with others. We had been blessed with several years of reasonably mild winters leading up to the 2007 storm. Unfortunately, the good times often seem …


Letter Re: I Thought that I Was Ready!

I have just returned to my house after 6 days without power. I Thought I was ready. I had plenty of beans, Band-Aids, bullion and bullets. What I didn’t have was the stuff I needed to get through the first week of a massive power outage. We still had water, even though I had an additional 50 gallons of fresh, treated water for myself, The Beautiful Wife (TBW) and the pets. We had enough short term food that we were able to provide a chili meal for some of our friends and coworkers that were doing without. We had more …


Letter Re: The Importance of Testing “Dead” Batteries Before Recycling Them

James- I wanted to share a money saving tip that applies to inexpensively preparing for TEOTWAWKI. With so many digital devices depending on batteries these days, most of us are conditioned so that, when a device like a digital camera or other smart gadget tells us the AA or AAA batteries need replacing, we simply toss out the “dead” ones and put in fresh batteries. But are the batteries really dead? Usually, not all of them are. I have a handy little Canon digital camera that we use around the house for insurance documentation, family photo opportunities at parties, pictures …


Two Letters Re: A Simple Off-the-Shelf Solar Power System and Off-Grid Power Tools

James, Your readers recently bring up good points about the advantage of battery powered tools with solar recharging. The advice to use an inverter connected to a 12v deep cycle battery and regular corded AC tools was good advice also, since the batteries may not last very long. Having just recently purchased a set of Ryobi one+ tools myself, I found a seller on ebay selling an adapter for the one+ tools. It plugs into the tool in place of the battery then you can plug an AC DC power supply into it. This will give the best of both …


Two Letters Re: A Simple Off-the-Shelf Solar Power System and Off-Grid Power Tools

James- Thanks for the interesting article on the Ryobi 12v solar setup. Just wanted to chip in some advice on Ryobi batteries: Of the name brand cordless tools, Ryobi seems to have the worst NiCd battery quality. When used carefully, they will work well for a couple of years. If pressed hard, they will die a much earlier death. I have found that some packs will have a bad cell, dramatically shortening the entire pack’s life after only a few months. I’ve experienced this with 9.6v, 14v, and 18v Ryobi setups. Even the healthier packs, when pushed hard, particularly with …