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I just got a 12V lithium battery and the manual said it can be connected directly to a solar panel. These batteries have an internal BMS which will disconnect it over a certain voltage or current. Devices you have connected to it may not like seeing 21V when the battery disconnects. All...

Regardless of chemistry, they all say to measure the voltage after there has been zero current for 15 minutes. Charging or discharging can change the voltage. Many battery monitors do coulomb counting with you setting an arbitrary full condition and fudge in some numbers for self-discharge...

Old thread, but you can convert that 4V to a higher voltage at lower current minus some loss in electronics. Power remains about the same. As to what charging a capacitor with a solar panel looks like, I recently did this experiment to test a solar panels power point voltage. I am simply...

The future will be energy management systems. I heard of one person in England that gets paid to turn his water heater on at night to stabilize the grid, it is internet connected. Solar systems generate power at the wrong times to be much use to the grid. Many solar homes now have monitors to...

I imaging it is similar to a mercury one. One interesting book which would likely hold information about it, at least hydrogen as a conductor is the book James Dillon Cobine GASEOUS CONDUCTORS. My copy is a thousand miles away. It has been in print for more than 70 years, the bible of things...

No, this one is in the western US. It is hard to define firsts. This one had enough voltage to create a glow at night. It was significant enough to get a mention in the book First 100 years of IEEE, or something like that. Haven't looked at it in probably 20 years and it is a thousand miles...

Tesla was an idea guy and showman. My impression was he never made anything actually work to a useful state. That was left to other engineers. Advancements always came from industry sectors you would never expect. Like, where was the first real high tension electrical transmission line built...

It is amazing work considering there were no resistance meters and a volt meter couldn't be made until resistance was understood. All you had was a swinging magnet, like shaped bars of different metals and batteries that seemed to do something though you didn't know what. This was flying blind.

Ohm wasn't too happy how it worked out either. He was ridiculed and lost his job as a teacher and had an utterly miserable life as a result. The detractors kept adding more batteries in series and the current wouldn't change. They never took into account that the batteries used had very high...

A friend had a gas welding mixer that combined C)2 and argon which went out of calibration. It used a hot wire bridge, one in CO2 and the other looking at the mix. Over time the CO2 one corroded slightly and wouldn't calibrate. Factory said he had to buy an entire new unit. I just changed the...

There are many battery voltage heating elements available. Still, 300W is about the practical limit for 12V as wiring loss becomes a factor. A heating element is only rated for so many watts per inch and that heat density should not be exceeded. Higher volts is a better way to proceed with grid...

Back in the late 60's I repaired audio equipment. Transistor manufacturing was still in its infancy. They would sell a family of transistors with each number increase a higher breakdown voltage. I did a lot of car radios and the output transistors had a high failure rate. I bought the lowest...

I'm a thousand miles away for the summer. Several other items. Posted to bookmark the thread.

I have the first HP desk calculator with a CRT and delay line for memory. It has this interesting feature; the keyboard mechanically locks up while it is doing a calculation. Odd that this was easier done mechanically than with electronics. I'm away so will picture some stuff later.

I produce domestic hot water with PV. While less efficient in collecting space vs thermal solar, it is far more economical. Supplemental PV water heating on a cost basis can be better than a heat pump. True success in a water heater is it turns off. That PV energy can be used elsewhere like air...