What batteries to pair with Xtar PB2S

Hello all. Apologies for the newbie questions as power banks, chargers and batteries are somewhat new to me.

I recently bought the Xtar PB2S to charge my USB devices (mobiles phones) while on the move.

According to reviews it is able to both charge and output at QC3 protocol.

I need to buy batteries to pair with this power bank. But I am not sure what type, brand or model I should get.

The criteria or tradeoffs might be:

  1. Longevity under QC3.0 recharge and discharge stresses - which I really want to take advantage of
  2. Overall capacity
  3. One cell or two

Assuming that cost is less important (within reason) should I be considering 21700s or 18650s? Should I consider mixing two battery types?

Any advice is appreciated. Thanks in advance for your responses.

Edit: Just want to add that I also bought the Vapcell S4 plus charger. If it can be used to charge the batteries overnight could I eke out better longevity?

Don’t mix types. Any pair of 5000mah+ 21700s. I use Samsung 50E for mine.

There’s no reason to make types, but the two bays are completely independent. There’s no issue if you have mismatched cells in the PB2S.

I didn’t know that, thank you.

Me, as well. I bought four 50Es for my PB2S, but buy them from Li-Ion Wholesale, as their stock is more recent than Illumination’s, where I got a pair from and my charger. 18 month’s difference, FWIW.


Thanks all for the comments.

I see available the LG M50 and Samsung 50E for reasonable rates.

Also I see Vapcell’s 48X (repackaged Samsung’s) seems to be talked about in another thread as having exceptional charge cycles (up to 3000).

When not in use would storing these batteries in a freezer help resist deterioration?

Nearly any 21700 should be able to support QC3.0. Might as well grab the highest capacity you can find. I use 50Es in mine.

I can’t think of any good reason to use one cell instead of two. You would be cutting your capacity in half for no reason. I’m sure there are much smaller form factor power banks available if you are willing to settle for 5k mAh or less.

Thanks all for the comments. I’ve decided to go with one of Vapcell’s offerings.

If I were to use these batteries intermittently, say once or twice a month or perhaps less frequently, how should I be storing them in between uses?