b4 I go guy new batteries, I was wondering if you had insight on WHICH SPECS MATTER as far as this device goes i.e. Low discharge current & high mah, or high discharge current & low mah, visa versa etc.
It's a give-and-take. You
need a battery capable of maintaining a discharge current higher than what you will be using it at. You
want the highest mAh available, that still provides that adequate discharge current.
I believe (don't take my word for it) the AL85 cuts off when the battery drains to about 3.4 volts. If you're going to be using it at the full 85 watts, that's drawing 85/3.4 = 25 amps. Add 10% to power the device itself, you're looking at around 27.5A as a maximum (it will be lower when the battery has more charge, or if you select less than the full 85W).
Here is a recent battery chart posted by
@Mooch. The numbers might need a little explanation:
CDR = Continuous Discharge Rating - this is the "every day" level you can use a battery, and still maintain good performance and battery life. From the man himself (emphasis mine): "CDR is not a safety or performance limit. It is a statement about how hard you can discharge the battery every single cycle, from 4.2V down to 2.5V, without losing more than a certain amount of capacity, or gaining a certain amount of internal resistance, after a certain number of cycles. It is the "every day" level you can operate at and still get good performance and good overall battery life. The CDR has almost nothing to do with safety except that
because it is chosen to ensure decent cycle life it ends up setting a discharge current level that results in a huge safety margin." Note: CDR = "huge" safety margin. See MVA, below.
Mfg. CDR = Manufacturer's stated CDR - this is a useless spec, designed to sell product. Ignore it.
Actual CDR = the rating given by Mooch, based on his tests.
MVA = Max Vaping Amps - This one is tricky. Mooch recommends you not exceed this value, for purposes of personal safety in case of stuck button or other mod malfunction that results in continuous auto-fire. A continuous discharge at this current will generate a lot of heat in the battery (up to 212°F externally, I believe was his cutoff for this figure) and drastically shorten the lifespan of the battery (it might last for 50 charges, or it might last for 2 charges; you never know) but, other than potentially burning your hand if you grab the hot battery, this
should not (no guarantees) pose any risk of personal harm. However, since we don't discharge our batteries continuously, you can in practice get away with drawing currents even higher (Mooch even goes so far as to say "much higher") than this, barring such a malfunction, without incident.
The Sony VTC4 (CDR: 23A, MVA: 30A, 2100mAh) has been a popular choice for quite a while, now, and I use several of them myself. There is also the new VTC5A [note the "A" - not the same as VTC5] (CDR: 25A, MVA: 30A, 2500mAh) that seems slightly better in both respects, but has not had as much time yet to prove itself. If you'd prefer to stay under CDR and not mess with MVA at all, then the LG HB2, HB4, and HB6 all have 30A CDR (and 35A MVA), but only 1500mAh capacity.
