DIY Box Unregulated Box Mod - 450W Build Log

[JohnnyDill]

And seriously, do you possibly think that I am going to vape at 450?

Well, lets see. The name of this thread is "Unregulated box mod 450W build" and the debate here revolves around vaping at .03 ohms. I think this thread is headed to the "Not advisable" dumping ground. There is no way to make this setup even remotely safe at said current levels, IMO.

 

[Kevin littell]

Just hook it up to a 900 CCA Marine 12 volt battery...Battery problems solved!!!

 

[bwoodroof]

Came from Sony VTC4s Spec Sheet

 

[bwoodroof]

Just hook it up to a 900 CCA Marine 12 volt battery...Battery problems solved!!!

And carry it in a backpack at VCC

 

[rhelton]

In all seriousness, the battery's will sag long before you see those kind of amps. They may still vent, probably will with repeated use that way.

Whatever I guess



Ill watch your a big boy

 

[WKS01]

Came from Sony VTC4s Spec Sheet

View attachment 381318

Again that chart is taken out of context. The chart is located in a section of the data sheet referring to cell packs protected with additional circuitry. Also, considering Sony has never stated the cells can be safely used at those ratings for daily use and the lack of information in that section in general it is quite silly to use it as a safety measure.

Check me on this WSK01

RDS (each) = 0.0017 ohms
RDS (2 in Parallel) = 0.00085 ohms
RDS (4 in Parallel) = 0.000425 ohms

I = 123 A
I^2 = 15129 A

P = I^2 * RDS

P(2 in Parallel) = 15129*0.00085 = 12.85W (6.43 Watts Per Mosfet)
P(4 in Parallel) = 15129*0.000425 = 6.43W (1.61 Watts Per Mosfet)

You are not using the correct RDS_on value. The 1.7mohm max rating is for a 10V V_gs which is not what is being used here. You are triggering at the battery voltage so between 3.6-4.2V. This will cause a higher RDS_on.

 

[bwoodroof]

RDS (each) = 0.0022 ohms (Extrapolation from data sheet for 3.6V)
RDS (2 in Parallel) = 0.0011 ohms
RDS (4 in Parallel) = 0.000425 ohms

I = 123 A
I^2 = 15129 A

P = I^2 * RDS

P(2 in Parallel) = 15129*0.0011 = 16.64W (8.32 Watts Per Mosfet)
P(4 in Parallel) = 15129*0.00055 = 8.32 (2.08 Watts Per Mosfet)

 

[bwoodroof]

I know that is it taken out of context, I plan on load testing the batteries and checking temperature before using them that low. Plus I never plan on going below .1 when vaping

 

[rhelton]

Got any more pics

 

[Visus]

That chart is not out of context.

These batteries also power that electric car to 60mph under 4sec theres like over 6k of em in there all 18650 sony vtc's.
I think its why they don't disclose vtc5 built specifically for the tesla..

He is battery safe sorta-- the builds would have to be either triples or quads with some thick gauge.
If you mistake and get dead remember visus on your policy, I was on your side that the batts can handle the amps but no way you could vape 400 watts that would burn a hole to china if it got even a hint of dry wick..

 

[rolf]

you could use a water cooled system from a computer ..maybe an instant on fan w a heatsink ?
your resistance looks like a short to me glad you have a meter to mesure that low!
to me it makes no sense and it absolutely scares me!!!
but then my mind is made up ..don't confuse me with the facts..
hope to get the flavor you are looking for.

 

[dr g]

Came from Sony VTC4s Spec Sheet

View attachment 381318

This is not a rating for the battery. This is the specification for the safety circuit. The rated discharge for the battery is 30A. As the chart says, the safety circuit must operate above 30A.

 

[Visus]

Im just gonna leave this here

http://www.rightwingnews.com/misc/s...-blew-legs-e-cigarette-explodes-like-grenade/

 

[NewCloudzCity]

Great information. Im looking to build 2 boxes. 1 in series and 1 in parallel

 

[NikZak]

Which MOSFETs are you actually using? 3034's?

 

[AzPlumber]

Came from Sony VTC4s Spec Sheet

View attachment 381318

It seems minds are made up but I'll offer this anyways. The continuous amp rating is the max a cell can safely migrate lithium ions. A high amp discharge above this max rate will quickly deplete any readily available lithium ions and the cell must then be allowed to recover. Obviously the higher the pulse is a longer down time is needed. Without knowing the full cycle time for each pulse rating this chart is useless for vaping.

 

[rhelton]

Got anymore pics, I am not condoning in any way that you go that low I think I made that clear a few days ago. But I am interested on how your build went? You did a really good job on the wiring I seen.

 

[bwoodroof]

 

[bwoodroof]

That chart is not out of context.

These batteries also power that electric car to 60mph under 4sec theres like over 6k of em in there all 18650 sony vtc's.
I think its why they don't disclose vtc5 built specifically for the tesla..

He is battery safe sorta-- the builds would have to be either triples or quads with some thick gauge.
If you mistake and get dead remember visus on your policy, I was on your side that the batts can handle the amps but no way you could vape 400 watts that would burn a hole to china if it got even a hint of dry wick..

I just wanted to overbuild, like you said i never plan on vaping @ ~400W but to be safe I am building this way.

 

[bwoodroof]

Got anymore pics, I am not condoning in any way that you go that low I think I made that clear a few days ago. But I am interested on how your build went? You did a really good job on the wiring I seen.

Thanks, I actually had to redo most of the wiring to get the additional mosfets into the box. But I sorta like how it came out.