Test/review of Xtar PB2S Charger & power bank

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chiclet_fanboi
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I made a breakout board to connect my multimeter and a few switchable resistors do add load (if the device throttles because of voltage drop). First thing, the amperemeter of my unit reads way low (300-400 mA). It doesn’t matter how you trigger the higher voltage modes (QC or PD), it always behaves the same.

I managed to get 14.5 W out of the unit in both 9 and 12 V mode. In 12 V mode you can actually draw 1.4 – 1.5 A, but the voltage has dropped to about 10 V at this point. More than that and resets. In 9 V mode it didn’t drop as bad, but at 1.7 A it cuts out. My phone seems to see “oh I’m connected to a 18 W PSU, I’ll draw 18 W which therefore leads to an instant cut-off with the powerbank. I’ll measure the current the phone draws from its original mains adapter as soon as the battery SoC is low.

I got a full refund on my unit.

EDIT: Pixel 3a draws up to 1.9 A in 9 V mode.

Couchmaster
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FYI, Illum has them on sale for $17 and change, and free shipping over $50.

d_t_a
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While re-reading the review, I noticed that this one is the PB2S with the “Red LED” display, also mentioned here: http://budgetlightforum.com/comment/1549467#comment-1549467

Is it possible that the “Red LED” PB2S has some internal differences from the regular “white LED” variants? (The “Red LED” PB2S is possibly an earlier variant?)

ZoomieFan
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Somehow I can’t manage to change the PB with more than 1.7A.
I use short quality USB cables and my wall chargers* are 2.4A and 4A.
Could it be limited by my cells (2×21700)?

*= Regular USB, not PD or QC

Chargers: 1xBasen BD01 5/5, 1x Gyrfalcon All-88 4/5, LiitoKala: 3x100 3/5, 2x202 3/5, 1x402 3/5., MiBoxer C4-12 3/5.
Flashlights: DQG Tiny III 26650 5/5, FiTorch MR35 3/5, Haikelite SC26 HD 3/5, Lumintop Tool AA/AAA 4/5, Nitecore LA10, Sofirn C01 BLF 3200k/5600k 2/5, Zebralight H600Fc 3/5.
Powerbanks: EasyAcc 26800 mAh 3/5, Xtar PB2 4/5, Xtar PB2S 5/5
Waiting for: (DQG Tiny) 21700 EDCs.

d_t_a
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ZoomieFan wrote:
Somehow I can’t manage to change the PB with more than 1.7A.
I use short quality USB cables and my wall chargers* are 2.4A and 4A.
Could it be limited by my cells (2×21700)?

*= Regular USB, not PD or QC

Do you mean charging the powerbank or the powerbank charging a device (eg. smartphone)?

If have a USB meter, can check the voltage. Based on my experience with powerbanks, usually a bit lower voltage causes charging current to drop.

ZoomieFan
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When charging the PB itself, the display of the PB reports it charges at 1.7A.
And that’s the highest I ever saw. Usually the highest is 1.6A.
Sometimes 0.7A and when I pull out the charger and plug it back in it’s up to 1.6A again.

Chargers: 1xBasen BD01 5/5, 1x Gyrfalcon All-88 4/5, LiitoKala: 3x100 3/5, 2x202 3/5, 1x402 3/5., MiBoxer C4-12 3/5.
Flashlights: DQG Tiny III 26650 5/5, FiTorch MR35 3/5, Haikelite SC26 HD 3/5, Lumintop Tool AA/AAA 4/5, Nitecore LA10, Sofirn C01 BLF 3200k/5600k 2/5, Zebralight H600Fc 3/5.
Powerbanks: EasyAcc 26800 mAh 3/5, Xtar PB2 4/5, Xtar PB2S 5/5
Waiting for: (DQG Tiny) 21700 EDCs.

TimMc
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Is it normal for the PB2S to terminate at 4.175V when charging a single 18650 or 4.185V when charging two 21700 cells?

XTAR kindly held a GAW for Xmas and sent me a PB2C and RC2-200. The PB2C terminates at 4.201V. Smile

The PB2S would be perfect if it terminated at 4.20V and held 18650’s slightly more securely.

d_t_a
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TimMc wrote:
Is it normal for the PB2S to terminate at 4.175V when charging a single 18650 or 4.185V when charging two 21700 cells?

XTAR kindly held a GAW for Xmas and sent me a PB2C and RC2-200. The PB2C terminates at 4.201V. Smile

The PB2S would be perfect if it terminated at 4.20V and held 18650’s slightly more securely.

I’ve also tried charging a few different batteries on the Xtar PB2S, it seems the end voltage may depend on the battery’s resistance and maybe ‘contact resistance’?

21700 battery will have better contact than 18650 on the PB2S charger/powerbank, so I think that may factor the slightly difference in end-charge voltage.
Also, a higher-resistance (not so high-drain battery) will get terminated and then have more voltage drop than a high-drain (low resistance) battery, at least that’s true for batteries when I tried charging on different chargers (which would likely also be true for the PB2S).

The charge termination current appears to affect the end-charged voltage of the battery (lower charge termination current will charge high-resistance batteries closer to the target voltage than a high charge termination current).

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