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For example you often hear people say: ‘You can’t use that battery in
a mechanical mod, it’s a regulated mod battery only.’
This is nonsense. A battery will have an mAh rating and an amp
rating. The bigger the mAh rating, the longer the battery will last
and the higher the amp rating, the lower you can run a build on
a mechanical mod or the higher you can turn up the power on a
regulated mod.
As long as the amp limit is not being exceeded on either device, they
are perfectly safe to use in either.
I
Ohm’s Law
R
Ohm’s Law is very easy to calculate. Although most app-based
calculators use the same method to work out the required amp
rating to operate safety, we suggest that there are two calculations:
one for mechanical/unregulated devices and the other for regulated
devices.
This is because a mechanical device loses voltage as the battery
is used. A regulated device will use the electronics inside to deliver
a constant voltage until the battery is no longer capable of fi ring.
When a regulated device is still supplying full power to the RDA or
tank even when the voltage of the batteries has dropped, the amps
being pulled is higher.
Calculating the required amp rating for a mechanical device is
simple: Volts (4.2 nominal for the batteries we use) / resistance (The
ohms of the coil in the RDA/tank):
4.2 volts / 0.20 ohms = 21 amps needed
4.2 volts / 0.14 ohms = 30 amps needed
4.2 volts / 0.28 ohms = 15 amps needed
Three different batteries could be used to operate a mechanical
device with the stated build in them at the continuous discharge
rating (CDR). This will be the fi gure that is shown on the battery wrap.
The battery will have a higher ‘pulse’ discharge rating. Unfortunately,
everyone’s idea of a pulse is varied. It’s suggested that a 1-2 second
draw on a mechanical mod would fall within the pulse rating of the
battery. This is 0.1ohm which is a fairly standard build for seasoned
mechanical mod users.
The amp rating required for a regulated device is also simple to
calculate. Firstly, you should determine the maximum power of
the device and how many batteries it takes. This will give you a
maximum wattage each battery is required to handle if using max
power. If we take a 150-watt device that uses two batteries, it’s 150
/ 2 = 75 watts.
Now you should determine the minimum voltage the mod will fi re
at. This is normally stated on the outside packaging or the operating
instructions leaflet. This would normally be between 3.0 volts and
3.3 volts per battery. If we use 6.4 volts as a minimum voltage
requirement, the calculation is 6.4 volts / 2 batteries = 3.2 volts per
battery.
The sum for working out the required voltage for a regulated device
is as follows:
75 / 3.2 / 0.95 = 24.67 amps.
0.95 is used is to allow for any ineffi ciency in the regulators in the
device itself. The above calculation demonstrates that with a 150-
watt device using two batteries at full power, the batteries need to be
at least 24.67 amps. This throws the ‘30Qs are for regulated devices’
argument out the window. They are a 15-amp battery!
Wraps
We had a customer come into our store who had taken the wraps off
their batteries because ‘they look sick in chrome.’ We were mortifi ed
but the customer didn’t understand the importance of the wrap.
The outside of the battery is essentially the negative ‘–‘ contact and
the flat or nipple top is the positive ‘+’ contact.
The wrap insulates the negative sides of the battery. A damaged
wrap could cause a mod to auto-fi re or dead short the battery. A
dead short is our worst nightmare. When we see news articles about
batteries exploding in someone’s pocket, there’s a 99% chance it was
a dead short.
When a battery vents from being used above its amp rating, it will
normally fi zz and hiss and there will be an acrid smell, but that’s
about it. When a battery dead shorts, the heat generates so fast that
the explosion occurs quicker than the thermal cut-outs in the battery
can work. This is when the fi reworks happen. The end result, in some
cases, has been death.
Torn Wraps
A torn wrap on a battery inside a mechanical tube mod can cause
the device to auto-fi re. Juice can seep down between the inside wall
of the device and the outside face of the battery and make contact
between the mod and the tear in the battery wrap. This acts the
same way it would if the fi re button was activated.
Auto-fi re will only occur if the battery is used positive-up in the
device. Some devices state they should be run with positive down in
the device. A torn battery wrap and leaking juice in a positive-down
device could cause a dead short. This could turn the device into a
mini pipe bomb. This doesn’t need to be the case. The devices are
safe. It’s often the salesperson or user that isn’t!
Wrapping Up
As a retailer and a manufacturer of mechanical devices and wire/coils,
I have often been faced with a conflict of interest when refusing to sell
a mechanical device to someone who I feel isn’t educated enough to
use that device.
We want our staff and our customers to be safe. This requires a
knowledge from our staff that means we can continually educate the
users. It also requires the willingness to refuse a sale if we feel the user
does not have the knowledge needed to operate the device safely.
VAPER EXPO 97