Battery 6F22 OKcell JRGK 800mAh 9V USB in Li-Ion version with built-in converter

CMS 15768 42

TL;DR

A Chinese reusable 6F22 9V Li-Ion battery with a built-in USB charger and inverter promises direct charging from any 5V micro-USB supply.
The test discharged the battery on an artificial load from 8.4V down to 7.8V at 200mA, then repeated the measurement after a longer charge/discharge cycle.
Declared specs include 800mAh capacity, 1500 cycles, 48.5 x 26.5 x 17.5 mm size, and a 24.5g weight.
The first run yielded only 0.088Ah, later a deeper discharge reached 449mAh, while the battery self-discharged quickly and the charge indicator proved misleading.

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#31 17269574 11 Jun 2018 11:16

Janusz_kk Janusz_kk

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Post #31
17269574 11 Jun 2018 11:16

Kajox wrote:
Voltage above 9v until discharged.

This version of the meter does not make sense and due to interference, power consumption from the battery and the lack of signaling
by the meter that the battery is low, as george already described
at https://www.elektroda.pl/rtvforum/topic3469117.html#17263486
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#32 17301906 28 Jun 2018 16:59

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Post #32
17301906 28 Jun 2018 16:59

I added new information about the dispute at the end of the first post.
#33 17756342 05 Feb 2019 12:30

dprzyb dprzyb

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Post #33
17756342 05 Feb 2019 12:30

I took a chance and ordered this battery.
He arrived 2 days ago. Unfortunately out of order.
When connected to charging, it shows the full capacity almost immediately (all 3 LEDs are on) and the voltage at the terminals is 9.4V.
After disconnecting the cable, the voltage drops to 0V in 3-4 seconds :cry:

I have never made a dispute on Ali before. Question - should I first confirm receipt of the package and then set up a dispute or set it up right away?
#34 17756354 05 Feb 2019 12:37

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Post #34
17756354 05 Feb 2019 12:37

dprzyb wrote:
After disconnecting the cable, the voltage drops to 0V in line

What's on the other end of that cable?
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#35 17756360 05 Feb 2019 12:41

dprzyb dprzyb

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Post #35
17756360 05 Feb 2019 12:41

CMS wrote:
What's on the other end of that cable?

At the other end of the cable is a USB charger
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#36 17756374 05 Feb 2019 12:48

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Post #36
17756374 05 Feb 2019 12:48

It's no wonder it doesn't work. Current consumption too high.
#37 17756438 05 Feb 2019 13:23

dprzyb dprzyb

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Post #37
17756438 05 Feb 2019 13:23

I don't think we understand each other.
I connect the charger with a micro-USB cable to the battery to charge it. The charge indicator shows that the battery is full and there is 9.4V on its terminals. And now, when I disconnect the micro-USB cable from the battery, I can see on the meter how the voltage drops to 0V.
Aku is not burdened with anything. Well, maybe except the meter
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#38 17756504 05 Feb 2019 14:04

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Post #38
17756504 05 Feb 2019 14:04

Well, we didn't really understand each other. Looks like an internal short circuit.
#39 17756513 05 Feb 2019 14:09

piterek-23 piterek-23

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Post #39
17756513 05 Feb 2019 14:09

And does this "battery" need some load for it to work?
#40 17756521 05 Feb 2019 14:14

dprzyb dprzyb

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Post #40
17756521 05 Feb 2019 14:14

Probably not. I put it in the pyrometer and it didn't work ...

Tell me, colleagues, what to do with this dispute - to put it on before or after confirming receipt of the parcel?
#41 17756675 05 Feb 2019 15:40

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Post #41
17756675 05 Feb 2019 15:40

Set up a dispute up to 6 days before the seller's protection date.
Better to open a dispute before confirming the goods you've received.
#42 17756738 05 Feb 2019 16:12

dprzyb dprzyb

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Post #42
17756738 05 Feb 2019 16:12

Thanks for the advice.

I have one last question - in my case should I choose "Refund Only" or "Return Goods"?
#43 17756872 05 Feb 2019 17:18

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Post #43
17756872 05 Feb 2019 17:18

Refund only.
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Topic summary

✨ The discussion revolves around the testing and performance of a Chinese 9V rechargeable battery (6F22) with a built-in USB charging feature. Users share their experiences, noting that while the battery can be charged via a micro USB, its actual output voltage is lower than the standard 9V, typically around 8.4V. Several participants mention using the battery in multimeters, highlighting its suitability for low-current applications. Concerns are raised about the battery's capacity, with some users reporting discrepancies between the advertised and actual performance. The conversation also touches on the internal structure of the battery, suggesting it contains two lithium-ion cells in series without a boost converter, which affects its voltage stability under load. Issues with defective units are discussed, including one user experiencing a rapid voltage drop to 0V after charging. The community provides advice on handling disputes with sellers regarding faulty products.

FAQ

TL;DR: Tests show only 0.088 Ah—11 % of the advertised 800 mAh—under a 200 mA load [Elektroda, CMS, post #17262020]; “Most handheld multimeters draw just a few milliamps” [Elektroda, odalladoalla, post #17263475] Why it matters: choosing the wrong 9 V Li-Ion pack can give 10× less runtime than claimed.

Quick Facts

Declared capacity: 800 mAh @ 4.2 V [Elektroda, CMS, post #17262020]
Measured capacity: 88–449 mAh depending on 100–200 mA load [Elektroda, CMS, post #17262020]
Peak charge voltage: 8.4 V (2 × Li-Ion cells in series) [Elektroda, krisRaba, post #17263233]
Recommended discharge limit: 6 V (standard 6F22 spec) [OldSkull, #17262740]
Typical price: ~26 PLN per cell (June 2018) [Elektroda, CMS, post #17262020]

Is there a boost converter inside the OKcell 9 V USB battery?

No. The pack uses two Li-Ion cells in series; output tops at 8.4 V and falls as the cells discharge. The only converter is a USB step-down charger on the micro-USB port [Elektroda, krisRaba, post #17263233]

Why does the battery show 8.4 V when fully charged, not 9 V?

Each Li-Ion cell charges to 4.2 V. Two cells give 2 × 4.2 V = 8.4 V. Marketing rounds this to “9 V,” but real voltage is lower [Elektroda, CMS, post #17263249]

What usable capacity can I expect at 100 mA load?

When discharged to 5.8 V with a 100–120 mA load, users measured about 449 mAh—56 % of the claim—before protection cut-off [Elektroda, CMS, post #17262020]

Why did I get only 88 mAh in my test?

A 200 mA load exceeds the pack’s 100 mA continuous rating, causing early voltage sag and capacity loss. Lower the current to ≤100 mA for realistic results [Elektroda, Kajox, post #17263849]

What is the maximum safe discharge current?

Sellers list 100 mA continuous; protection or voltage collapse occurs above that point [Elektroda, Kajox, post #17263849]

How often do I need to recharge the pack in a handheld multimeter?

Users report 2–3-month intervals with light meter use (a few mA draw), roughly matching 400–500 mAh effective capacity [Elektroda, dudik56, post #17262319]

Does the four-LED indicator show true state-of-charge?

No. At 7.8 V the indicator still reads 75 % even though many devices already warn of low battery [Elektroda, CMS, post #17262020]

What edge-case failures have been seen?

At least one cell dropped from 9.4 V to 0 V within seconds after charging—likely an internal short; a refund was required [Elektroda, dprzyb, post #17756342]

Will converter noise affect precision instruments?

Because this version has no boost converter on the output, there is minimal switching noise, making it suitable for multimeters [Elektroda, Ficu, post #17262565]

How do I dispute a faulty battery on AliExpress?

Open a “Refund Only” dispute before confirming receipt and at least six days before buyer protection ends [Elektroda, CMS, post #17756675] 2. Upload photos or a short video showing voltage drop. 3. Request full refund; shipping back usually isn’t required.

Why does the pack self-discharge to 8 V within weeks?

Internal BMS and indicator circuitry draw micro-amps continuously; over several weeks this parasitic load lowers open-circuit voltage by ~0.4 V [Elektroda, CMS, post #17301906]

Is a super-capacitor 9 V replacement a better choice?

Super-caps offer near-infinite cycle life but provide milliamps for only seconds. For portable meters, Li-Ion packs still give hours of runtime [“Supercap 9 V battery”, Hackaday].