Acceptable batteries for an Evic VTC mini with upgraded firmware (75W)

[ziggytrix]

I've never vaped over 40W, so this question isn't really out of necessity, but rather because I'm trying to understand.

The batteries I have are the confusingly named purple eFest 35A and the LG HG2, which are both 20A max continuous discharge, correct?

Can I just plug my wattage and resistance into an amp/volt calculator and make sure it's under 20A? What happens if I go over 20A? I don't plan to, but on another forum I visit I think people might be vaping 1 ohm TC coils at 75W with 20A batteries. Are they just getting lower than expected performance, ruining their batteries, risking combustion, none or all of the above?

I've been reading up on this for the last couple hours and it's starting to do my head in. Does temperature control come into play at all in battery selection?

 

[sucram]

I am not 100% sure about the specific batteries you are using, but in general going over the amp limit will lower life minimum, worst case you can vent one.

You would need to find out if the temp setting you have it set at is exceeding the amp limit. If your unit shows the current watts its putting out it will make it a lot easier, just vape in front of a mirror to see what its running at.

 

[JimScotty0]

You can change the mod to display AMPS on the bottom row so you can actually see the draw on the battery when you fire it. Just keep it within the battery specs. I have been using it with several batteries at 40W in TC mode and see the draw between 10-15 watts. It starts out high to heat the coil and then gets much lower very quickly to maintain the temperature. Much of that will be different depending on your coil build and its demand for power.

 

[leekeylee]

I have bought an evic vtc mini and was wondering about batteries, and it all depends on the amps your build is going to draw from the battery.

Have a look at steam engines battery amp calculator

http://www.steam-engine.org/batt.asp

you can select certain types of batteries and you can set up what your build is i.e. coil ohms and wattage you vape at etc and it will tell you how many amps it will draw from the battery.

As I am using mine for my GS Air-M in wattage mode (not interested in temp control) at about 15 watts on a 1.2-1.5 ohm coil I am drawing just over 3 amps so I decided to get the LG HG2 3000 mah batteries as these are a 20a continues discharge.

Also check out the battery section on here as their is a lot of information on different types of batteries and Mooch does a lot of tests on different types of batteries

https://www.e-cigarette-forum.com/forum/forums/batteries-and-chargers.828/

hope this helps

 

[Croak]

Most of the good 18650s we use were made for power tools, and the 2-5 second hits we typically take are really what the battery makers consider in the "pulse" time range, rather than "continuous". So going a wee bit above 20a for a few seconds at a time is safe.

On top of that, the resistance of a TC coil increases FAST when vaping on it, so even a worst-case 0.05 Ni200 coil at max wattage will only be that low for a brief instant, before the resistance more than doubles, drastically reducing the amp load.

And finally, on top of that, you have a built-in 20 amp limit on the eVic VTC itself in VW/TC mode, it won't allow you to pull more than that.

 

[KenD]

Resistance won't factor into the amp draw of a vw device (including tc devices). Wattage and battery charge level (lower charge = higher amp draw) are what need to be taken into account. The calculation is:

Amps = watts / battery charge (use the mod's cut-off voltage)

Modify that for mod efficiency (90% is a good number).

TC complicates matters, but the above formula is accurate enough.

Sent from my GT-I9100 using Tapatalk

 

[ziggytrix]

Thanks guys, this is all very helpful. Just installed the 2.0 firmware on my VTC mini and it has amps on the screen always now. Kinda tough to see it while you're using it, but it's there if you pulse it.

 

[xiios]

Seems to me that it displays output amperage (to coil) instead of input (from battery).

For 40W I would have expected to see amperage between 10-14A (at battery levels 4.2-3.4V plus taking into account mod efficiency and some voltage drop under load).

What I actually got:
1) 0.07Ω dual Ni200 coil, TC mode with 200°C / 40W. Wicking is sufficient to stay around 40W so TC won't kick in. Amperage goes from 20+ down to 17.5A. This can't be input amperage. It is certainly output amperage and nicely corresponds to resistance changing from 0.07 to 0.13Ω. In this case the initial amperage should actually be about 24A but I guess the mod has not enough time to display it and catches up only at about 20.5A.

2) 0.53Ω dual kanthal coil, Power mode / 40W. Amperage shown is 8.5A. Which is correct for output.

The number that actually matters is input amperage and in Power / TC mode it can be calculated from watts as has been pointed out by KenD.

 

[KenD]

Seems to me that it displays output amperage (to coil) instead of input (from battery).

For 40W I would have expected to see amperage between 10-14A (at battery levels 4.2-3.4V plus taking into account mod efficiency and some voltage drop under load).

What I actually got:
1) 0.07Ω dual Ni200 coil, TC mode with 200°C / 40W. Wicking is sufficient to stay around 40W so TC won't kick in. Amperage goes from 20+ down to 17.5A. This can't be input amperage. It is certainly output amperage and nicely corresponds to resistance changing from 0.07 to 0.13Ω. In this case the initial amperage should actually be about 24A but I guess the mod has not enough time to display it and catches up only at about 20.5A.

2) 0.53Ω dual kanthal coil, Power mode / 40W. Amperage shown is 8.5A. Which is correct for output.

The number that actually matters is input amperage and in Power / TC mode it can be calculated from watts as has been pointed out by KenD.

That's a shame. Makes the ampere mater kinda useless :-/

Sent from my GT-I9100 using Tapatalk

 

[ziggytrix]

That's a shame. Makes the ampere mater kinda useless :-/

Then it goes nicely with the puff and time counters.