After more thorough testing of the used LiFePO4 battery that I described in my previous post, I’ve reached the sad conclusion that it’s essentially a worthless piece of junk. Encouraged by stories from mobile-solarpower.com and other sources, I’d hoped this…

My used LiFePO4 battery (lithium iron phosphate) arrived yesterday. Who buys used batteries? I do, apparently. I’ve been putting the battery through its paces to see how much of the original capacity of 45 Ah / 675 Wh still remains.…

What’s the most expensive component in a small off-grid solar setup? You might assume it would be the solar panels, but the cost of panels can be surprisingly low. For many people, the batteries are the single most expensive element…

While sheltering in place this week, I’ve been tinkering with a small-scale setup for solar power generation. I’ve got a 100 watt solar panel, and access to the sun. What fun things can I do with this? Is it actually…

Recently I’ve been looking at battery datasheets, in preparation for an off-grid solar project. I’ve noticed something strange about the “constant power discharge” numbers in the datasheets of several 12V lead acid batteries. Here’s an example from a 20 Ah…

My family and I have been ordered to shelter at home until at least April 7, to help stop transmission of COVID-19 in the San Francisco area. Many of you may already be living under similar orders, or will be…

Sometimes my brain works in unexpected ways. I haven’t started any new electronics projects lately, but my thoughts have been spinning in other directions. Last weekend I jokingly told my kids that I was starting a home-based ore smelting business. Because…