Hand-Crank Generator Battery Life for Lighting

[AdmiralCheez]

The larp I go to is run on private property, so one of the advantages is we can make permanent alterations to the buildings. My next character is going to be from the steampunk kingdom, so I wanted to incorporate some elements of that into the place he lives in. The buildings are basically home-built sheds that max out what you can legally do without filing for a construction permit. So, a carport frame with wooden fence segments for walls, no insulation, and tarp roofs. We do have wood-burning stoves in most of them.

The first idea I want to do is electric lighting. Generators are too noisy, I can't run an electric line out there, and there's too much tree cover to make solar panels viable, so I'm thinking of installing a hand-crank generator and battery. It doesn't require fuel, and I can dress it up to look in-game. Not to mention, it's probably one of the safest options for leaving in the wild for a month with no use. Problem is, I'm not good at electricity math, so I'm trying to figure out the best setup to get maximum light time for minimum cranking.

Does anyone have any experience with these types of generators, or have any words of wisdom/caution? I don't even know if it would be worth the investment, so all information is appreciated.

[wumpus]

First suggestion would be to use DC-based LED lighting (since LEDs want DC anyway this shouldn't be hard), preferably low voltage (but try to avoid a long kludgy chain, ideally you want to go straight from the LEDs from a driver (LEDs want constant levels of current, most power supplies produce constant levels of voltage) that will take a wide range of DC (roughly the range of your batteries).

I'd also want to replace a hand crank with leg crank (presumably based on a cheap used walmart-special bike [being heavier is a virtue here]).

After that, it is a matter of trying to find a balance between available alternator/generators, batteries, and LEDs and devices that convert from one to the other.

[halfeye]

Hand cranked torches advertise 1/2 hour per 30 seconds winding, but that's optimistic when brand new, they don't keep it up when they're older, and you don't get more light time from cranking for longer.

It's basically down to the batteries they use being the cheapest they can get away with.

If you have magic batteries you can do whatever you want. However, in the real world it's not that easy, getting better batteries should be possible, though you'd have to crank longer to get longer lighting time.

[AdmiralCheez]

First suggestion would be to use DC-based LED lighting (since LEDs want DC anyway this shouldn't be hard), preferably low voltage (but try to avoid a long kludgy chain, ideally you want to go straight from the LEDs from a driver (LEDs want constant levels of current, most power supplies produce constant levels of voltage) that will take a wide range of DC (roughly the range of your batteries).

I'd also want to replace a hand crank with leg crank (presumably based on a cheap used walmart-special bike [being heavier is a virtue here]).

After that, it is a matter of trying to find a balance between available alternator/generators, batteries, and LEDs and devices that convert from one to the other.

I'm kinda thinking of rigging up some gears and a new handle and replacing the built-in one to get even more speed (and thus, power) from a casual crank, though a pedal setup might be cool if I can get enough space for it.

So I would need the generator to lead into the battery, then from the battery to a power supply, then to the LED lights. It sounds like I might just want to find a string of battery-powered LED lights, then just detach the battery pack and wire in a bigger battery connected to the generator. Or somehow wire the generator directly to the battery compartment with a rechargeable battery in it. Hmm... if that's possible, it might be the cheapest option.

Hand cranked torches advertise 1/2 hour per 30 seconds winding, but that's optimistic when brand new, they don't keep it up when they're older, and you don't get more light time from cranking for longer.

I had one of those years ago. Worked pretty well for about a month, then the battery stopped holding a charge and it only lit as long as you cranked it. And the amount of light it gave off was entirely dependent on how fast you cranked it. Wasn't too useful.

It's basically down to the batteries they use being the cheapest they can get away with.

If you have magic batteries you can do whatever you want. However, in the real world it's not that easy, getting better batteries should be possible, though you'd have to crank longer to get longer lighting time.

So I should really look to invest in a good battery then if I go that route. Maybe give it a good wind-up at the start, and every time someone comes in or leaves, ask them to crank the battery.

[Excession]

We do have wood-burning stoves in most of them.

How about using one of these for power? The simplest option is a thermocouple. Might need to adjust the parts for higher temperatures compared to that one.

Steam might be doable as well if you're feeling brave, but be wary of exploding boilers as they can kill. You could also use a wood gasifier to run gas lights, which via flame out, leaks, and carbon monoxide production have even more ways to kill you.

[Radar]

How about using one of these for power? The simplest option is a thermocouple. Might need to adjust the parts for higher temperatures compared to that one.

Steam might be doable as well if you're feeling brave, but be wary of exploding boilers as they can kill. You could also use a wood gasifier to run gas lights, which via flame out, leaks, and carbon monoxide production have even more ways to kill you.

Never, ever go into steam power unless you really know, what you are doing and have access to quality equipment. Those things are seriously dangerous and good boilers will not be cheap.

The thermocouple idea is really neat and as simple as it gets.

[jayem]

They do weight powered (led's) for some project in Africa.
You have a pulley/gear system so the side with the giant weight moves slowly while the other end turns fast (this is then directly connected to a small generator).

On the plus side it's more steam punk, and with no battery that can't play up.

https://en.wikipedia.org/wiki/GravityLight

On the negative you get very little light*time (I thought it would just have the edge over the torches but the maths in the article says no)

Although you possibly could rig some system where you have multiple weights lifted up in the day, so they just need connecting.
In fact if you don't use Sand, you could have more weight (and you could always lift them in units), and you could have a bigger drop distance (although that has H&S issues).

Have you had a closer look at the solar panel battery combo. The house ones produce kW of energy, and you probably don't need that.
Car batteries can do 40Amp/Hours at 12 Volts (0.5kWH). And you can definitely get pretty small trickle chargers (which I'm pretty sure managed to recover my battery at least once) it looks like they are about 5-10W, so with a weeks charging for an evenings use that's a couple of proper house LED lights. And because the chargers are so small/low power you might be able to find a bright spot or stick it up a pole.
+of course you could when you plan to do a double nighter you always have the option of bringing a good battery from home.

The best is probably a combo, 2*solar/battery for a kettle and lights for OOC moments, and then the crack and torchlights for In game.

[Excession]

They do weight powered (led's) for some project in Africa.
You have a pulley/gear system so the side with the giant weight moves slowly while the other end turns fast (this is then directly connected to a small generator).

On the plus side it's more steam punk, and with no battery that can't play up.

https://en.wikipedia.org/wiki/GravityLight

On the negative you get very little light*time (I thought it would just have the edge over the torches but the maths in the article says no)

That with some sort of added clockwork to chain to multiple weights would neat. Especially the sudden blackness every 20 minutes filled with loud clunks as the next weight queues up. Sounds steampunk compatible to me

[AdmiralCheez]

How about using one of these for power? The simplest option is a thermocouple. Might need to adjust the parts for higher temperatures compared to that one.

Steam might be doable as well if you're feeling brave, but be wary of exploding boilers as they can kill. You could also use a wood gasifier to run gas lights, which via flame out, leaks, and carbon monoxide production have even more ways to kill you.

The thermocouple sounds cool. I could build one of those pretty easily, and it would be real nice for the winter when we have large heat sources going constantly. I might have to build a summer one for use with candles, though, when we don't have the stove running in the smaller buildings. The one in the tavern is always running, though. I bet they could use some electric lights.

Steam would be awesome, but we have a hard enough time keeping the chimneys completely sealed between events, so that's probably too dangerous for us.

They do weight powered (led's) for some project in Africa.
You have a pulley/gear system so the side with the giant weight moves slowly while the other end turns fast (this is then directly connected to a small generator).

On the plus side it's more steam punk, and with no battery that can't play up.

https://en.wikipedia.org/wiki/GravityLight

On the negative you get very little light*time (I thought it would just have the edge over the torches but the maths in the article says no)

Although you possibly could rig some system where you have multiple weights lifted up in the day, so they just need connecting.
In fact if you don't use Sand, you could have more weight (and you could always lift them in units), and you could have a bigger drop distance (although that has H&S issues).

Ooh, now that's an interesting idea! I like that. It sound like it's relativey low maintenance, and probably the safest option too, which is even better.

Have you had a closer look at the solar panel battery combo. The house ones produce kW of energy, and you probably don't need that.
Car batteries can do 40Amp/Hours at 12 Volts (0.5kWH). And you can definitely get pretty small trickle chargers (which I'm pretty sure managed to recover my battery at least once) it looks like they are about 5-10W, so with a weeks charging for an evenings use that's a couple of proper house LED lights. And because the chargers are so small/low power you might be able to find a bright spot or stick it up a pole.
+of course you could when you plan to do a double nighter you always have the option of bringing a good battery from home.

The best is probably a combo, 2*solar/battery for a kettle and lights for OOC moments, and then the crack and torchlights for In game.

There might be a few spots to mount a solar panel depending on which building I get, but that's still to be determined. Some are heavily covered in trees, and some have some openings for light to get through regularly. I'll have to see.

[monomer]

They do weight powered (led's) for some project in Africa.
You have a pulley/gear system so the side with the giant weight moves slowly while the other end turns fast (this is then directly connected to a small generator).

On the plus side it's more steam punk, and with no battery that can't play up.

https://en.wikipedia.org/wiki/GravityLight

On the negative you get very little light*time (I thought it would just have the edge over the torches but the maths in the article says no)

Dang, that's a pretty neat setup.

It looks like their next-gen light is a hand-cranked with battery version that can also be charged using a solar panel or mains power, and has a USB port to plug in other accessories. It will supposedly last 120 hours at a 5 Lumen output, and 6 hours at 160 Lumens when fully charged. So you could charge it at home then bring it along, top it up during the day with solar, and crank it for extra oomph when needed. Or if you want to leave it there for extended periods, even with indirect light, it will probably charge pretty well with solar.

The problem is that the expected delivery is April 2019, which on Indiegogo time could mean anything, and final specifications are subject to change. It's also not as Steam-punky as the Gravity version.

It is also basically just a 3200 mAH battery with some other physical doodads included, so you could probably rig up something similar for a lot cheaper with a phone power bank, some USB lighting, and a hand-cranked / solar charger.

[AdmiralCheez]

That's actually pretty good for the crank-time-to-light-time ratio I wanted. I wonder how hard it would be to replicate that, but without their lamps.

[LordEntrails]

I like the thermocouple idea. Not sure what the output is.

If you go the crank route, I would look at a motocycle battery. Should be cheap and 6V should be enough to power a bunch of LEDs.

I can say that typical solar systems use 24V deep cycle marine batteries, but those are king of expensive on their own. I would try to setup circuits of lights that use the same voltage as the battery, then you don't need any converter. If you want more lights, then you can make several parallel strands. Do note if you have long electrical runs you will get voltage drop from the wires.

For instance, say you go with the 6V battery and you find that your LEDs you want to use are 0.5VDC each, then put 10 of them in series and attach to your wires. Then the other side is you put your crank and generator to charge the battery. For that, you can look at some camping and survival solutions for such.

I like the idea of a leg crank, you could put it with a comfy chair, so people who get the comfy chair have to do a little work :)

[LordEntrails]

So here's some actual numbers. 3VDC and 350mA for this one LED. Lots of variation. They also sell the drivers there too. PRobably have lots of info on making your own.

https://www.ledsupply.com/leds/luxeon-rebel-white-leds

[AdmiralCheez]

So here's some actual numbers. 3VDC and 350mA for this one LED. Lots of variation. They also sell the drivers there too. PRobably have lots of info on making your own.

https://www.ledsupply.com/leds/luxeon-rebel-white-leds

Ooh, nice, I'll have to look through their catalog. I've got some other projects I want to tackle that need LEDs as well.

[druid91]

Not a hand crank, but maybe look into something along the lines of a spinning wheel for your crank setup. Linking a larger wheel to a smaller one that spins the crank means more bang for your buck.

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[gomipile]

Not a hand crank, but maybe look into something along the lines of a spinning wheel for your crank setup. Linking a larger wheel to a smaller one that spins the crank means more bang for your buck.

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So, a stationary bicycle or a treadle flywheel?

[AdmiralCheez]

It is also basically just a 3200 mAH battery with some other physical doodads included, so you could probably rig up something similar for a lot cheaper with a phone power bank, some USB lighting, and a hand-cranked / solar charger.

Coincidentally, I just won a phone power bank in a raffle, so the most expensive part of that option is already acquired. So for now, I'll probably do some experiments with it and see how much life I get out of it. If it'll last two nights in a row, I may not even need to recharge it, and I can hide the device inside a prop. That would certainly be the easiest route, though a lot less fun.

[LordEntrails]

Coincidentally, I just won a phone power bank in a raffle, so the most expensive part of that option is already acquired. So for now, I'll probably do some experiments with it and see how much life I get out of it. If it'll last two nights in a row, I may not even need to recharge it, and I can hide the device inside a prop. That would certainly be the easiest route, though a lot less fun.

No no no! You must make visitors work for their comfort and your company!

[AdmiralCheez]

No no no! You must make visitors work for their comfort and your company!

True, that is half the appeal!