I'm going to build one of these, really nice simple design. I would guess the lack of repeatability is down to the fact that your dealing with very small resistance, things like the contact of the clamps and possibly temperature may throw it out.
I think variance would be due to different temps and moisture in the air, would be cool to know for sure tho. Maybe you could get it setup then heat the wire a bit and test again to see if the amps you pull changes
The metal is a better conductor than the water, so the majority of current flows through the metal wire. Some current probably flows through the water, but no damage is done because the water prevents the metal from getting hot.
Water sucks as a conductor. Until it gets a bunch of crud in it, anyway. Last time I measured a cup of filtered tapwater, it was a couple million ohms...
how did I not see this till now! great build Josh. I ordered the halogen bulbs already so I'll try that method for now. is it just as good just annoying?
+neil morehouse halogen is less hassle but annoying because bright and hot. The wire load is a hassle dealing with a big bucket if water but easy after that. You may not be able to get lower discharge rates at all depending on what type of wire you use. Mine won't go much below perhaps 40 or 50 amps. I haven't tested the exact bottom end but I was trying to get 20 amps and didn't have enough wire.
you dont think the current flow is limited by the windings a like you stated? as far as testing an 80c battery and you are only seeing 60-65 amps. Seemed like most of the batteries you tested did about 60-65 amps
+Cognomen current flow is limited. That's the point. I don't want to short the batteries and destroy them. The batteries did 60 amps because I set the load up to draw about 60 amps. I could make it draw more by putting the clamps closer together but given how badly most batteries perform at 60 amps, I don't see a point in going higher.
+Joshua Bardwell bummer! I was hoping I had found a new option for my broken water heater! But seriously thanks for the response and thanks for all you do!
This is a battery discharging humidifier (if water boils) and also an electromagnet!! 3 in 1!!
I'm going to build one of these, really nice simple design. I would guess the lack of repeatability is down to the fact that your dealing with very small resistance, things like the contact of the clamps and possibly temperature may throw it out.
+Lee Hudson just difficult clamping in the same place every time.
I think variance would be due to different temps and moisture in the air, would be cool to know for sure tho. Maybe you could get it setup then heat the wire a bit and test again to see if the amps you pull changes
The wire heats somewhat during the tests, but the amps don't change significantly.
Couldn't you just use romex (insolated house wire) ?
I was wondering what you were using as a load. That's a pretty nifty way of doing it.
+Silvara Majere it was suggested by a commenter so I can't take credit for the idea.
Thanks ... I love your work!!
My only consern would be the lack of contact between the clamps and the wire. Do you find the contact point gets hot?
+Revs it's all underwater. I don't think it gets very hot.
Will we see the spreadsheet from the 60A livestream test soon?
The video will go live Thursday the 2nd of June.
Not repeatable? Could it be the water? Are you using distilled water? Deionized water?
+Bruno Gomes not repeatable because the clamp doesn't go back in the exact same place every time.
Oh ok. :p
still waiting on the video where you drink the pine bucket tea
Not going to happen.
How does adding water to the bucket not short out your coils?
The metal is a better conductor than the water, so the majority of current flows through the metal wire. Some current probably flows through the water, but no damage is done because the water prevents the metal from getting hot.
Water sucks as a conductor. Until it gets a bunch of crud in it, anyway. Last time I measured a cup of filtered tapwater, it was a couple million ohms...
how did I not see this till now!
great build Josh. I ordered the halogen bulbs already so I'll try that method for now.
is it just as good just annoying?
+neil morehouse halogen is less hassle but annoying because bright and hot. The wire load is a hassle dealing with a big bucket if water but easy after that. You may not be able to get lower discharge rates at all depending on what type of wire you use. Mine won't go much below perhaps 40 or 50 amps. I haven't tested the exact bottom end but I was trying to get 20 amps and didn't have enough wire.
you dont think the current flow is limited by the windings a like you stated? as far as testing an 80c battery and you are only seeing 60-65 amps. Seemed like most of the batteries you tested did about 60-65 amps
+Cognomen current flow is limited. That's the point. I don't want to short the batteries and destroy them.
The batteries did 60 amps because I set the load up to draw about 60 amps. I could make it draw more by putting the clamps closer together but given how badly most batteries perform at 60 amps, I don't see a point in going higher.
+Joshua Bardwell gotchya. would be neat to see max amp draw though! haha.
+Cognomen max would be something like 200 amps followed by smoke and fire.
awesome.
How hot will the water get during testing?
+Eric Baker tepid at best.
+Joshua Bardwell bummer! I was hoping I had found a new option for my broken water heater! But seriously thanks for the response and thanks for all you do!
+Joshua Bardwell you should check this guys channel if you haven't seen it. Killer load test setup. th-cam.com/video/uJyDK1X2rCc/w-d-xo.html
+XSspeeds wow.
Dang! You know your audience.
th-cam.com/video/gZEdDMQZaCU/w-d-xo.html
Just a big heater. Not a idea, bro.
+Damon Keller hater...
Bro, I didn't have the sound up but wouldn't it be a good idea to have sand in it or would it be bad because of the heat build up?
Joshua Bardwell not hating. Hell everyone's videos helps me out a lot.
+Damon Keller the wire would burn without the water.
What about the coils from a space heater? You may have a meltdown from that bucket.