Box Mods and Battery Amps – Choosing a Safe Cell
First, let's look back to some prior posts on Ohm's law, battery safety, and proper battery handling. If there's something we don't go into too much detail on here, it's probably been addressed in one of these three posts.
Okay, so how should one go about choosing a battery? First, there are two types of cells out there – those from legitimate manufacturers, and those from "re-wrappers," which are companies that don't actually manufacture batteries but instead buy stock, often "seconds" that don't pass quality control checks with the original manufacturer, and market them to specific groups, such as flashlight or vape enthusiasts. There are only three manufacturers of batteries that make cells suitable for vape use – LG, Samsung, and Sony. If you're not buying one of these three batteries, you're probably not buying an ideal cell for vaping. Re-wrappers, including names like Efest, MXJO, and Vappower, have been known to claim fake specs that can be downright dangerous – Efest alone has been caught labeling 10 amp batteries as 35 amp, and their "3100 mAh, 20 amp" cells are generally considered unsafe above 12 amps.
Why does the amp rating matter so much?
Amps, labeled by responsible manufacturers in "continuous discharge" ratings and by suspect ones as "pulse discharge" (only achievable for a period of time constituting perhaps a fraction of a second, though sometimes more), describe the power your vape tank is commanding when you hit the power button.
The post on Ohm's law will help you with precise calculations, but for simplicity's sake let's say a single 20 amp cell can power a mod at up to 75 watts, two 20 amp cells in parallel can provide up to 150 watts of power, and three cells can go to 225 watts. If you need more power, you need a battery with a higher continuous discharge rating.
Conveniently, most single-battery mods cut off at around 75 watts of power – a safe limit for 20 amp cells, which are the most popular high-discharge batteries on the market as of this writing. But some dual-battery mods promise up to 200 watts of power, which isn't attainable without using 30 amp cells.
Granted, most of us never get close to straining our batteries at these upper limits – but if you like pushing the envelope with hot, huge clouds (or if you're using a mechanical mod), your choices are limited. The only known cells that can safely reach 30 amps are the Sony VTC3 (1500 mAh) and VTC4 (2000 mAh), along with the LG HB2 and HB6 (both 1500 mAh).
The ability to store power (measured in milliamp hours, or mAh) and to release it rapidly upon command (discharge rating) are at odds – the faster you want to drain your battery, the less room in the cell for storage, as more space is dedicated to heat dissipation. This is why high-discharge batteries have a lower storage capacity in general.
Heat dissipation, though, is important! Stress your battery by asking it to deliver more power more quickly than it's capable, and the result is that power gets turned into heat, causing venting (super-hot chemicals or chemical steam shooting out of the battery) or explosion (exactly what it sounds like). Everyone's heard a story from a vaping critic or just by watching the news about "exploding e-cigarettes." Chances are, it's someone using a re-wrapped battery and trusting the usually-fake specifications on the label, but read the battery handling post for other important tips on avoiding meltdown.
Let's say you're not going to push the limits, though – 75 watts on a single battery or 150 on a dual-cell box mod is plenty, or you're going to use the triple-cell Reuleaux if you want to go crazy high on the watts. You've got a lot more options.
Sony's other popular vaping battery, the VTC5, goes to 20 amp and is rated at 2500 mAh capacity. This is, however, one of the most counterfeited batteries in existence, and there are better options cheaper. Samsung makes very popular and reliable 20 amp cells, the baby blue 25R2 and the lime green 25R5, both also rated for 2500 mAh. LG offers the HE3 and HE4, both delivering 20 amp discharge ratings at 2500 mAh again, along with the new HG2, which is again 20 amps but has a whopping 3000 mAh storage – it's by far the favorite workhorse for most everyday vaping applications.
While safety concerns are real when it comes to batteries (and this applies to ANYTHING with a battery, from your car to your mobile phone), by using a safe cell and a trusty battery charger (don't charge in your mod by using the micro-USB cable designed for software updates unless in a pinch or if your mod doesn't have removable batteries), you can mitigate virtually all of the risk involved.