I did a quick search on here, and it seems to be a matter of when you stack you have to keep track of those batteries and ALWAYS use them together. Once you have stacked two batteries you can't use them individually, you have to charge them together, you need to place them in the right places when using them (I can't remember now if it said you have to alternate which one is on top or not) and you always have to put them in - in the proper direction... the only thing that sucks about all of that is the never using them as separate pieces if you want a short version to go out. I am going to have to think on that, or just wait until I get more batteries.
Either way, it's a matter of following the rules when stacking. I searched because I was having a hard time understanding what the problem was. I mean flashlights and other battery operated things have used the 'stack'em' method of battery installation for decades. I guess the big thing there is they arne't usually rechargeable batteries. But then again, even with regular rechargeable batteries that came about in the past few years, I don't recall it being an issue.
Right!
They should be used as
mated pairs. I mark my pairs as 1A and 1B, 2A and 2B, etc.
They could be charged together at the same time, but that isn't really necessary. I use a pila IBC charger. It has two charging bays. What's most important is that they both be charged to the same level, and at about the same time. If you only have a single bay charger, then charge them separately and let the charger take care of the charge level. Charge one and then the other right after that.
Of course you have to insert them properly, as with any battery. If you insert them with the positives touching (or the negatives touching), that does not create a short or any other problem, as no difference in potential is created between them. You can test this with any two batteries and a voltmeter. The charges only add together if they are inserted with a (+) touching a (-), and with a (+) on one end and a (-) on the other end.
(+)=====(-)(+)=====(-)
.. 4.2V + 4.2V = 8.4V when fully charged.
....Battery 1
.....Battery 2
If you insert them backwards (negative first), the Mod's protection should handle that and not come On, but it's best to be careful and not insert them backwards.
If you want to use the Vamo in 18350 mode in town, then get another set (so you have a spare in town) to be kept for that purpose, and mark them appropriately (or don't mark them at all and let the paired markings differentiate). It all comes down to adequately marking the batteries so you know what is what.
It does not matter if you always insert 1A first and then 1B, because they both have the same charge level, and have always been used together since they were new, so they always have the same wear levels on them. What matters is that you always use a mated pair from the time they are new. Marking them helps keep track!
Since they are stacked, they will also discharge at the same rate.