[Review] XTAR PB2 USB Power Bank and 18650 Charger

WalkIntoTheLight · 2018-06-23T16:38:10.000Z

This is a review of the XTAR PB2 power bank and charger. This is a 2-slot 18650 charger with a digital readout that also doubles as a rapid USB power bank for smart phone charging and other devices.

There is a video review of the charger I put up on Youtube, here:

The charger and specs can be found here:

www.banggood.com

XTAR PB2 Rapid Smartphone Power Bank & Versteckt LCD Display 18650...

Nur US$15.71, kaufen Sie den besten XTAR PB2 Rapid Smartphone Power Bank & Versteckt LCD Display 18650 Batterie Ladegerät 2Slots USB Kabel Online-Shop zum Großhandelspreis.

It is presently on sale for $12.99 until June 30th. After that, you can use discount code “ad8cd9” to bring the price to $13.69.

The charger was provided by Banggood for review purposes. I receive no other form of compensation.

Overview:

The Xtar PB2 is a nice little charger that serves as both a dual 18650 charger, as well as a powerbank for charging your other USB devices. It incorporates a LED display that shows the remaining percentage capacity of the device, as well as provides error information (such as if you install a battery in backwards).

The unit is very light, but it feels well built. A magnetic cover gives easy access to remove or install ICR/INR/IMR lithium-ion 18650 cells, and the magnets are strong enough to prevent any accidental removal of the cover.

It has a sleek look, and is also very functional.

Interface:

The Xtar PB2 is very easy to use, and is fully plug & play. Remove the magnetic cover to install one or two 18650 cells. Use a USB cable (one is provided) to connect the micro USB port on the Xtar to a USB charging outlet. The Xtar will charge your batteries until full, while displaying the progress on its LED display.

The power bank function is just as easy. With batteries installed, connect the cable to the full-sized USB port on the Xtar, and the other end to your smart phone. Your smart phone will immediately begin to charge, and the device will show the remaining capacity of your batteries.

There is a button on the side of the Xtar that will temporarily activate the LED display to show you the remaining capacity. You only need to press it if the Xtar is not connected to anything. When the device is being used, the display will always be lit.

18650 Charging Function:

As a charger, the Xtar PB2 can charge either 1 or 2 cells at a time. They must be standard lithium-ion 18650 cells. Due to the small size of the battery compartment, only unprotected flat-top cells will fit. Button-top cells might fit, but they would have to be not much longer than 65mm. Protected cells are too long.

Just install your cell(s), and plug a USB cable (or the one provided) into the micro USB port on the Xtar. Plug the other end into any USB wall charger (or port on a computer). The Xtar will immediately begin charging your batteries. It will display a progress readout on its LED panel, showing the percentage of charge your batteries have.

When charging, the digits of the LED display will slowly flash, indicating it is charging. When complete, the flashing will stop and the readout will show 100%. Disconnect the charger, and either remove your charged batteries or leave them in it to use it as a power bank.

If you install 2 cells, they will each charge at 1 amp. If you install 1 cell, it will charge at 2 amps. This assumes you connect the charger to a 2.1A USB outlet, otherwise it will charge at a slower rate (whatever is available from your USB outlet).

If you install 2 cells, they do not have to be at the same voltage, nor be similar in capacity. If voltages are different, the device will show the average capacity in its LED display. When charging is complete, both cells will be at 4.2 volts.

The charger provides a full charge of your cells, terminating at 4.20v. It uses a standard CC/CV algorithm for charging.

It also provides for 0 volt activation of cells to bring severely discharged cells back to life. Though, in my opinion, you should probably just recycle cells that have been discharged completely.

USB Power Bank Function:

The Xtar PB2 can operate as a USB power bank with either 1 or 2 cells installed. If 2 cells are installed, it will provide a 5v 2.1A USB output to charge your other gadgets. If only 1 cell is installed, it will provide a 5v 1A USB output.

Just connect the included micro-USB cable into the full-sized USB port on the Xtar, and the other end to your smart phone or other gadget. Your phone will begin to charge, and the Xtar will display the remaining percentage of its batteries.

The charging efficiency is up to 92%, and you can fully charge your phone from the Xtar, with plenty of capacity remaining.

Acceptable Batteries:

The Xtar PB2 does not come with batteries, so you must provide your own. It can take either one or two 18650 lithium-ion cells. The cells must be the standard kind that take a charge to 4.2 volts. They must also be unprotected flat-top cells, as the battery compartment is limited in length.

Batteries do not have to be the same brand, capacity, or have the same voltage when installed. So, basically, anything goes.

If using just 1 cell in the Xtar, I recommend it be a high-drain cell like a Samsung 30Q or similar. This is because the charger will use a 2A charge with only 1 cell installed in it. This would be hard on a low-drain cell. So, if using low-drain cells, you should probably install 2 of them, which will cause them to be charged at a slower 1A rate.

Specifications:

Construction: Plastic casing, with rubberized coating. Magnetic cover. It is not waterproof, so don’t get it wet.

Size: 110mm x 50mm x 25mm

Weight: 55g (without batteries)

Input: micro USB, 5V up to 2.1A

Output: standard USB, 5V 2.1A

Protection: reverse polarity protection, short, over-voltage, low-voltage.

Heat: The unit does not get hot either being charged or charging something else.

Package contents: Charger, USB cable, manual, box.

My impressions:

Pros:

- Sturdy, grippy surface.

- It is a fairly efficient USB power bank.

- 2.1 amp power bank is rapid for most devices.

- Fast charging of 18650 cells.

Good termination for full charge of 18650 cells.

Cons:

- Will only fit unprotected flat-top 18650 cells.

Summary:

This is a great little charger for both charging your 18650 cells, and using the powerbank function to charge your smart phone or other micro-USB devices. If you use good batteries in it, it functions as a very respectable 7000mAh powerbank for travel or emergency purposes.

That’s all for now. Thank you for reading.

maukka · 2018-06-23T17:04:22.000Z

Thanks for the review! I don’t mind the battery pickyness, but the fact that it shuts down on a relatively high minimum load (300 mA) is a deal breaker. Can pretty much only charge other power banks or phones but not power other low power devices.

deleted-200707 · 2018-06-23T19:28:34.000Z

It drops out trying to charge my Sandisk Sansa Clip MP3 player. Pushing the side button restarts the charge butt then shuts off.
bummer!

Same thing on my MecArmy SGN5 and my UltraTac K18 mini charger…. :person_facepalming:

Nor my Nitecore TIP

In contrast., my Rofis MR70 charged all of them with no problem.

atbglenn · 2018-06-23T19:31:48.000Z

I tested mine with two new freshly charged Panasonic 18650GA 3500 mAh cells installed, and I got less than half the capacity when discharging using a YZXstudio ZY1270 USB Power Meter and a 2.1 amp load. I’ll do another test to confirm.
That said, I did the same test with a 20,000 mAh Xiaomi power bank and got over 13,000 mAh. That’s slightly better than their real output spec listed on the power bank.

WalkIntoTheLight · 2018-06-23T20:53:43.000Z

atbglenn:

I tested mine with two new freshly charged Panasonic 18650GA 3500 mAh cells installed, and I got less than half the capacity when discharging using a YZXstudio ZY1270 USB Power Meter and a 2.1 amp load. I’ll do another test to confirm.
That said, I did the same test with a 20,000 mAh Xiaomi power bank and got over 13,000 mAh. That’s slightly better than their real output spec listed on the power bank.

Did you measure it in watt hours, to take into account the voltage boost needed?

atbglenn · 2018-06-23T21:13:09.000Z

WalkIntoTheLight:

atbglenn:

I tested mine with two new freshly charged Panasonic 18650GA 3500 mAh cells installed, and I got less than half the capacity when discharging using a YZXstudio ZY1270 USB Power Meter and a 2.1 amp load. I’ll do another test to confirm.
That said, I did the same test with a 20,000 mAh Xiaomi power bank and got over 13,000 mAh. That’s slightly better than their real output spec listed on the power bank.

Did you measure it in watt-hours, to take into account the voltage boost needed?

No I didn’t. I’m re-testing now. It seems to be doing better now. I’ll post the display readout when I’m done. It will show the watt hours. So far with 35% left on the display shows 18.97 WH and 3.75 Ah’s. I’ll show the final results.

I might have messed up. I’m not sure if I reset the USB tester to zero. I’m now recharging the Xtar and will do another test. I will post my results tomorrow. Sorry about that.

atbglenn · 2018-06-24T16:30:41.000Z

Here’s the results of a fully charged PB2 with 2 Panasonic NCR18650GA’s drained till the PB2 shut down. The current was set at 2 amps. The PB2 shuts down when the display reads 00.

deleted-200707 · 2018-06-24T18:05:36.000Z

Well, I really wanted to like this.
Butt if it won’t charge all my stuff then it’s not as useful as my TOMO and will not go on long trips with me.

WalkIntoTheLight · 2018-06-24T18:09:57.000Z

atbglenn:

Here’s the results of a fully charged PB2 with 2 Panasonic NCR18650GA’s drained till the PB2 shut down. The current was set at 2 amps. The PB2 shuts down when the display reads 00.

Okay, so somewhere around 80% average efficiency, if the cells were drained to around 2.7v (though, there’s not much energy below 3v). Did you note what their voltage was after the test?

atbglenn · 2018-06-24T18:52:54.000Z

WalkIntoTheLight:

atbglenn:

Here’s the results of a fully charged PB2 with 2 Panasonic NCR18650GA’s drained till the PB2 shut down. The current was set at 2 amps. The PB2 shuts down when the display reads 00.

Okay, so somewhere around 80% average efficiency, if the cells were drained to around 2.7v (though, there’s not much energy below 3v). Did you note what their voltage was after the test?

Sorry I didn’t. I’ll do another test and let you know.

Newlumen · 2018-06-24T19:31:38.000Z

maukka:

Thanks for the review! I don’t mind the battery pickyness, but the fact that it shuts down on a relatively high minimum load (300 mA) is a deal breaker. Can pretty much only charge other power banks or phones but not power other low power devices.

It happened to me too… was charging nitecore tini and it stopped…

BlueSwordM · 2018-06-24T19:41:14.000Z

@atbbglen, the only measurement that matters is watt-hours, not anything else.

When drained down to 3.2V, the NCR18650GA have about 2.9Ah of capacity drained at 1.5A, so about 10.5Wh.

So, with 2 cells, 10.5Wh*2= 21Wh

92%*21Wh= 19,3Wh. So they actually have accurate specs.

IMO, the only flaw in this power is the way too high shutoff current. The minimum should be 80mA, or maybe just 50mA.

WalkIntoTheLight · 2018-06-24T19:45:15.000Z

Newlumen:

maukka:

Thanks for the review! I don’t mind the battery pickyness, but the fact that it shuts down on a relatively high minimum load (300 mA) is a deal breaker. Can pretty much only charge other power banks or phones but not power other low power devices.

It happened to me too… was charging nitecore tini and it stopped…

Yeah, doesn’t seem to power low-charge devices (under 300mA). I don’t know of any work-around for this. Pressing the side button will force-start the charging, but it will automatically turn off after a little while.

It’s definitely aimed more at the smart-phone market. And, of course, as an 18650 charger.

Well, if you were stuck on an island with a few low-power devices and a USB hub/splitter, maybe you could charge a couple of them at the same time.

deleted-200707 · 2018-06-24T19:47:11.000Z

and I have to pry my Samsung 30Q button tops out with my knife!

BlueSwordM · 2018-06-24T19:54:06.000Z

Eh. I don’t really care for button top compatibility.

Most 18650 cells are flattop anyway. However, I do wonder why they didn’t go with a sliding mechanism instead of just tabs. Would have made cell compatibility much better and the use of button tops possible.

WalkIntoTheLight · 2018-06-24T21:26:40.000Z

BlueSwordM:

Eh. I don’t really care for button top compatibility.

Most 18650 cells are flattop anyway. However, I do wonder why they didn’t go with a sliding mechanism instead of just tabs. Would have made cell compatibility much better and the use of button tops possible.

My only guess is that they were designing it to be as small as possible. Using springs and allowing for longer protected cells might increase the length by as much as 10%. I guess they assume that most people use flat-tops now. This could be aimed at vapers, not just flashaholics, and from what I understand vapers almost always use unprotected flat-tops.

I only have one light that requires button tops, the BLF Q8. And, if I had to, I could crow-bar the 30Q button-tops into it, just barely. I don’t think I’d take a large light like the Q8 on any trips were I required a portable charger, though.

Zulumoose · 2018-06-25T03:50:17.000Z

The thing is, many of us would appreciate being able to standardise on a cell. Unprotected button tops, particularly the 30Q that is often available as a set of 4 with coupon, fit the bill perfectly, especially since the Q8. Anything that turns out not to be suitable for them is a disappointment.

WalkIntoTheLight · 2018-06-25T11:03:05.000Z

Zulumoose:

The thing is, many of us would appreciate being able to standardise on a cell. Unprotected button tops, particularly the 30Q that is often available as a set of 4 with coupon, fit the bill perfectly, especially since the Q8. Anything that turns out not to be suitable for them is a disappointment.

That makes some sense, but otoh some of my lights (mainly Zebralights) can only take flat-tops, so that is what I have standardized on. The Q8 is the only light I have that requires button tops, though most of my lights will take them.

I find the button tops on 30Q’s add unnecessary resistance, if the light doesn’t require button tops. So, I prefer to use flat tops whenever possible. Granted, the resistance is small, but any extra resistance on a high-drain cell is something to avoid if possible.

Speed4goal · 2018-06-25T11:16:12.000Z

If you can half decent solder you can make your own button tops with almost 0 added resistance. It helps to scuff the top of the cells with sand paper first.

WalkIntoTheLight · 2018-06-25T13:44:52.000Z

Speed4goal:

If you can half decent solder you can make your own button tops with almost 0 added resistance. It helps to scuff the top of the cells with sand paper first.

I did do that with some cells meant for the Q8, with some success. The solder seems stuck on the tops good, but I think it might have been too cold, as it’s a horrible lumpy mess. I evened them out with a dremel tool. Well, it works, though I prefer the nicer look of real button-tops I have for it. The solder blobs were really done just to try it.