diy solar

diy solar

Best way to burn some juice of a couple runners?

What size wire do you recommend if I use our iron?
If your iron is 200 Ohms it will be less than an Amp so still slow. Someone suggested on another thread a long coil of wire, long extension cord or anything that you could find that measured one or two Ohms.
 
It would have to be an electrical device that has a physical switch or is always on, or it will not work.
If you have that any 14 gauge wire or bigger should be fine, ie any decent size household copper wire or cords.

You want the lowest ohm device possible, less than 10 is best, 1-4 is perfect, check with any tester, they are $10 on amazon.

I tried a lemon with 2 copper nails in it, I was hopeful but it didnt work......

I even tried my kids old graphite pencils, its needs to be at least an inch long, cut the wood off first. attach with mini alligator clamps at each end.

The big orange home depot carpenters pencil work great.

1" or less or small pencil lead will glow red hot, its pretty cool!
 
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If your iron is 200 Ohms it will be less than an Amp so still slow. Someone suggested on another thread a long coil of wire, long extension cord or anything that you could find that measured one or two Ohms.
OK, this is the best solutions I have found to date, based on the hint by Ampster. I used a standard 50ft extension cord and shorted the live and neutral pins at one end, then tested the ohms from the now 100ft wire, It was between 1 & 2 ohms. Perfect.

I then shorted the battery between the 2 pins at the ST60 in the picture below, and the battery voltage dropped much quicker than any of the previous methods, most notably using a single cell At 3.3v.

Just do short 1-2 second connection times to start, the voltage drops quickly and heat will be generated with large cells. You could use a standard household light switch to turn the connection on and off. Use a multimeter to check the voltage change as you do this.

Make up a strong connection between the wires and you will have a reliable solution. The photo below shows just what I did for testing.

Hope this helps ...

671D0847-EB89-4C00-9284-E9F2314DDDDE.jpeg
 
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OK, this is the best solutions I have found to date, based on the hint by Ampster. I used a standard 50ft extension cord and shorted the live and neutral pins at one end, then tested the ohms from the now 100ft wire, It was between 1 & 2 ohms. Perfect.

I then shorted the battery between the 2 pins at the ST60 in the picture below, and the battery voltage dropped much quicker than any of the previous methods, most notably using a single cell At 3.3v.

Just do short 1-2 second connection times to start, the voltage drops quickly and heat will be generated with large cells. You could use a standard household light switch to turn the connection on and off. Use a multimeter to check the voltage change as you do this.

Make up a strong connection between the wires and you will have a reliable solution. The photo below shows just what I did for testing.

Hope this helps ...

View attachment 34445
You are a brave man. I don't have the cojones to do that. I'm discharging my high cell as I type this. Started with an iron as recommended here but it was pulling less than .3 amps. Switched to an old manual 12v charger and it pulling just under 1.3 amps in the 60a engine start mode. I can live with that.

I'm draining it at the end of the absorption charge and I am able to slowly up the float voltage higher than I could. It is now the second highest cell in my pack so when it's where I want it I'll drain the other high cell.

39.jpg40.jpg41.jpg
 
Switched to an old manual 12v charger and it pulling just under 1.3 amps in the 60a engine start mode.

That's a bad idea, you're injecting DC into a transformer, it may or may not fry depending on a lot of factors. Please use only fully resistive loads.
 
That's a bad idea, you're injecting DC into a transformer, it may or may not fry depending on a lot of factors. Please use only fully resistive loads.
Yike. Just saw this. I assume by "fry" you mean the 12v charger, not my Lischen cell?
 
The extension cord is the safest bet, no electronics to fry.
The longer the better. You could daisy chain them to make them longer.
It also draws a high current, so it works much faster.
 
The extension cord is the safest bet, no electronics to fry.
The longer the better. You could daisy chain them to make them longer.
It also draws a high current, so it works much faster.
I want to make sure I fully understand how this is done before I do it. So + and - of the cell are being shorted together with 50' of extension cord between? If you shorted the battery terminals with a wrench all hell would break loose. So the large gauge cable acts like a resistor?
 
Yes, the extension cord wire is thin and long enough to have a high enough resistance ;)
 
Exactly, its the same reason, your power tools don't work so well at the end of a long extension lead, its due to the voltage drop caused by the resistance of the long leads. Low voltages are particularly effected, that's why the utilities use super high voltages for long distances.

Look at my photo above, bridge the +/- ends of the 50ft cable so the wire becomes 100ft long.

Only connect the battery until the wire becomes hot, then disconnect till it cools down. The actual time will depend on the thickness of the wire and the length.
 
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I just tested the extension lead method above with a brand new 280ah LifePO4 cell.
I used a 14 gauge 50ft cord with a simple loopback (yellow wire below) making the wire 100ft long.
The total wire measured 2 ohms, 1 - 10 ohms is the sweetspot.
There were no sparks, nothing eventful connecting the wires.
No wires got hot, not even slightly warm
I checked the voltage every minute with a multimeter
The voltage dropped from 3.6v to 3.3v in 15 minutes
All in all, a success. I would recommend this method.
C35D9066-D328-43E0-927D-E8E762487E68.jpeg
 
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I use 16 gauge test leads and 14 inch lengths of .032 stainless safety wire I got at Lowes. One length is about 5A of draw at 3.2v. The wire will get melting plastic hot, but not red hot.
 
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