XTAR PB2S

How is the powerbank conversion efficiency bmengineer? And can it accommodate some longer unprotected 21700s like Lishen cells?

I got it yesterday, way too soon to say.

Max bay length looks like about 72 mm, but I can’t measure it super accurately.

Thanks a lot, mate.

It will be too expensive

Any hint about price?

MSRP $21.90

That sounds extremely reasonable.

Looks good, but I would’ve liked if there was also a micro usb port on board, just for more flexibility.

Otherwise, I’m very glad they’ve fixed the ridiculously high current cutoff issue, which limited the PB2s usefulness for me…

One of the nice things about the original PB2 was that it was such a compact charger/powerbank. What’s the PB2S like in comparision?

21.90$ looks ok… But hope a group buy or coupons to get at an even more low price.

About 15-18$ max would be nice

Thanks for the comparison. It’s quite a bit bigger. Not sure if it’s small enough to consider it a travel charger, but if you have to charge 21700’s it still pretty small.

Does it have an issue fully charging iPhones?

When does it go on sale?

I was told it was ready to be released, and available “soon,” but that was over a month ago.

We're waiting for our tracking number to scan in, estimated arrival next week.

Thanks for posting! This is interesting, and I do like most of Xtars chargers for their typically reliable and proper cc/cv termination. But its also a bit on the largish side. There was some verbiage in the review and product link that has me a bit concerned. It mentioned that when inserting a charged cell and a discharged cell, the charged cell would recharge the discharged cell. Hopefully the cells aren’t arranged in parallel. I would be concerned that the charged cell would directly discharge into the discharged cell without a controlled cc/cv method. Its unlikely and would be potentially dangerous, but probably worth testing just to make sure.

Hopefully Xtar has a copy in its way to HKJ for detailed analysis.

Xtar product link:

Google translate to English of Italian review:
https://translate.google.com/translate?sl=auto&tl=en&u=https%3A%2F%2Fwww.svapo.it%2Fdiscussione%2F111256-xtar-pb2s-caricatorepower-bank%2F%23comment-1566306

CC/CV - this is the simplest charge algorithm. The nickel charge algorithm with catching delta is much more complicated.

Where did you see any comments to that effect?

I think that was from the planet of the vapes review.

I think it was in regards to charging priority when it is plugged into a power source. So it will charge the more discharged cell first from external power. I don’t think it implied that it was charging from the other cell.

I just got one, and it’s nice! The “official” link is

which has anigifs to show how it charges/discharges.

True, it’s bigger’n the PB2, but this donk fits 21700s, too, that’s why.

Hell, today I needed to charge a 26650 (Cometa) and it fit it just fine. Sure, just one cell only, and the cover won’t fit, but to be able to charge even a moose like that in a hurry? I’ll live with “larger”. :laughing:

And there are 2 separate independent channels, so you can put one nearly-topped-off cell right next to one that’s almost dead, and there’ll be no problem.

The side-button lets you click to see the connection spex, then for battery 1, then again for battery 2.

This is my first XTAR charger, and I’m happy with it.

Oh, and it charged my phone just fine. Dunno about “The IPhone Problem”, but my normal phone worked fine. Was at like 36% or something, topped off, drained the PB2S down to 65% or so. Ymmv, of course.

Two fold. Maybe one-and-a-half fold.

1) The PB2’s low current threshold (290mA, according to HKJ) would prevent iPhones from fully charging to 100% before it shut off.

1.5) The USB output coding didn’t correspond to full “fast” (~2A) charging. Of course, iPhones don’t speak QC either, but newer ones do speak PD, so the PB2S appears to address that situation.

I’ll eventually pick up an S after I find a way to pawn off my PB2. I’m a sucker for detailed displays, and am done buying sealed power banks that are effectively trash after their cells expire.

Bmengineer tested the PB2S and it cuts off between 20 and 30mA in the normal mode so this is fixed. For even lower charge currents there’s the low power mode.