Mech mod

[Gary81]

The coils I am using are 3x28g nichrome core wrapped in 34g nichrome

 

[Mr Ripple]

The coils I am using are 3x28g nichrome core wrapped in 34g nichrome

If you increase the wrap guage to 10x the cores so 3x28g cores with 38g wrap it will heat up quicker and drain the battery less.
If you're going to use coils with that much metal mass you would be better off getting a twin cell mech.

 

[greenbrucelee]

I would go for .25 for safety and lasting reasons but I never use mechs

 

[speedfreek67]

For amp draw calculations you should always use the full charge of 4.2 volts.

This is not for an "extra safety barrier", it is your basic fundamental safety calculation.

In very simple terms, your fully charged battery is sitting there with a charge of 4.2 volts, and when you press the button you are completing a circuit with very low resistance, so low that you are almost short circuiting the battery.

This causes a hell of a lot of amps to flood out of the battery, working the battery really hard, and causing it's voltage to sag towards 3.7 volts.

So the 3.7 volts figure is the nominal output caused by the high amp load, not the input you use to calculate that load.

If you work any battery at loads approaching or exceeding it's constant discharge rate, you won't get a lot of time at that high load out if it.

So, if you want longer vape time you need to either change your vaping style to suit the equipment, or choose equipment better suited to your vaping style.

 

[Andy S]

I've been doing my research on battery safety, or thought I had from what I've worked out a 20700 cell at 3.7 amps will output 28.46a at 105.31w, so to me from what I have researched is within the battery capabilities, what I seem to have failed to realise is that 3.7v is not a full charge reading

Yeah mate, 3.7 is the nominal voltage, where the battery is most stable. It drops to that level fairly quickly and stays there or thereabouts for quite a while then it drops quickly again, but there will be a brief period where, if you've charged it to the max, you'll be drawing more power. On a mech, the Amps draw decreases as the battery drains whereas on a regulated device it increases. So on a regulated device you calculate your Amps requirement on the minimum voltage and on a mech you calculate it on the maximum voltage.
Of course, there's nothing to stop you sticking with your 3.7V calculations and not fully charging your battery because its going to drop to 3.7 fairly soon anyway. If you have a charger with a display that tells you what's going on you can just stop it when it gets to the voltage you want.

 

[Deleted member 54254]

LOL, like the sneaky correction, you baffled me before, but in my usual pre-christmas, not give a sh!t style, I let it slide

 

[Andy S]

LOL, like the sneaky correction, you baffled me before, but in my usual pre-christmas, not give a sh!t style, I let it slide

Gotta get up early to catch you, haven't I?
I was replying to Gary but hit the button while reading your post. I thought I was quick enough on the edit to go unnoticed but I guess you've got your alerts switched on.

 

[Deleted member 54254]

There's a few of the old timer mech users who would have approached this entirely differently but I don't see a generally positive reaction to going jihad on someone's ass. The thread also started in the early hours of the morning and I was more interested in the Vape Team, LOL

 

[Deleted member 58360]

Haven't seen it mentioned yet, so hey ho...

Re: battery (cell) life between charges.

If your cell is 3000mAh, that means effectively that it's rated to provide 3000mA for one hour, at it's nominal discharge rate - after that time it will be at a voltage considered 'flat' (somewhere within a couple of decimal points of 3V).

3000mA is 3A.

The nominal discharge rate will be nowhere near it's maximum discharge rate (in this case, the maximum is 30A, the nominal is likely to be something closer to 5-10A). The closer you get to the maximum, the less correct the capacity rating will be.

So, even ignoring the fluctuation due to discharge rate...

3A for one hour = 30A for 6 minutes.

Now stop ignoring the fluctuation, plus account for noticing a drop off in performance = possibly as low as 30A for 3 minutes (or less, maybe as low as one minute depending on how critical you're being on performance).

Say a 6 second puff, 10 puffs = 1 minute.

So with those figures something between 10 and 30 puffs and you'll be saying your battery is flat...

 

[shnazzle]

The one big issue with meching. Batteries just die. Forever swapping batteries