Other items that may be of use
You can still buy hurricane lamps. There is a campaign to rid Africa of these dinosaurs, substituting solar powered batteries. They are rightly said to be dangerous but so is stumbling around in the dark! It is still worth having one as a last resort.
If you live somewhere powered by batteries at some point you will be confronted with a choice. Something along the lines of "do I want a microwaved baked potato badly enough to sit in the dark the rest of the evening?"
Candles are just about OK when you run out of anything else. If they are in the centre of the room you cannot see anything but the candle. It’s best to position candles around the room with a reflective surface behind them. Big diameter candles produce much more soot than thinner ones.
But what about generators I hear you ask. Well they don’t have much place in this sort of lifestyle. I have an 800 watt kipor. It’s a good generator but it uses about half a litre of petrol an hour and if you think you can charge leisure battery from it will take about five hours in my experience. They are OK for power tools but you have to weigh that against the alternative hand tools.
If you have a source of free pallets and want to make things from the wood as opposed to burning them, a pallet breaker may be of use. Search a popular auction site for "pallet breaker". It can be seen being used on youtube. I don’t know why they cost £50 for a bit of bent metal.
Thermometers
Digital thermometers are on all the time and have two feet of flex so you can see the temperature of a fridge without opening the door.
Probe thermometers are only on for a minute after you have pressed on of the buttons. They can be used to measure the temperature in a saucepan or the top of a still. They can also tell when a pasty is cooked inside. 78 centigrade since you asked.
Mercury thermometers have two advantages. They don’t need batteries and they aren’t damaged if they get wet.
They all have their uses.
A digital thermometer, a probe thermometer and a mercury thermometer.