Test/review of Znter S19 9V 400mAh USB (Black-green)

Znter S19 9V 400mAh USB (Black-green)







Official specifications:

  • Name: S19 USB rechargeable 9V battery

  • Material: Fireproofing plastic shell

  • Cell type: A+ Lithium Polymer battery cell

  • Input: Micro USB (5V)

  • Output: 9V

  • Charge voltage: 4.25V

  • Battery capacity: 400mAh

  • Energy capacity: 3.6Wh

  • Battery life: >3000 times

  • Charge time: 1.5 hours

  • Compatibility: 9V battery

  • Color: Black and green

  • Size: 48mm*25mm*16mm

  • Weight: about 25g




This is a usb rechargeable 9V, it cannot be charged on a 9V charger.



The B battery only had half capacity, this makes me believe the cell consist of two LiIon cells in parallel and one of the cells was not connected in the B battery. For this reason I have shown the results for the A battery above, i.e. the battery with full capacity.





Behind the small hole in the bottom is a led that shows red while charging, it will turn off when the battery is full.








To charge the battery any (phone) charger with a micro usb connector can be used.



The output voltage is about 9.5V from start to finish and nearly independent of load. This means a battery gauge will show full until the equipment stops working.
One battery has a bit about 300mAh and the other a bit about 150mAh. It is interesting to note that the lowest load do not give the highest capacity/energy output, the boost converter is using a higher percentage of the energy at low load.









Charging current is measured at 5V and starts at 500mA, charge is terminated at 50mA.
The boost converter will discharge with about 0.1 to 0.2mA, when the LiIon cell is below to 2.5V the current will drop to below 2uA.


Conclusion

This battery is not the most impressive 9V I have seen with one battery partly defect.
It is a neat solution in some cases:
1) Charge (replace) batteries at regular intervals, to avoid them running down, i.e. do not need the fuel gauge.
2) Need 9V battery with high voltage.

Do not use the batteries for low power applications, the boost converter will drain the battery in 6 to 12 months.



Notes and links

How is the test done and how to read the charts
Compare to other 9V batteries: Alkaline/NiMH/Lithium/other

The boost converter will discharge with about 0.1 to 0.2mA, when the LiIon cell is below to 2.5V the current will drop to below 2uA.

0.2 mA pe hour or day? When the battery voltage hit 2.5V I think the boost converter is not working because low voltage protection disable step-up module.

0.2mA is constant, there is not time on it, if you say 0.2mAh it is per hour.
And you are correct with the low voltage protection, that is the reason the current drops.

Thanks a lot for the review! I had my eyes on these for a long time but always thought they were 2S li-ion with no boost converter of any kind on the output.

I got mine a couple days ago.
My question is the following: can I recharge the battery while there is a working load attached?
Thanks.

Yes. If the load is about 20mA or more the charging will never terminated.

This battery has been on sale more times during the autumn and I have collected 10pc until now.
It is strange that all mine are with pure English language on both the wrapper and the blister pack although they are from the same vendor as in the OP. Nowhere are the brand name ZNTER to be seen on mine. And I don’t seem to be able to Google the factory that makes ZNTER.
They contain two flat LiPo cells in parallel, marked 500mAh each.
A full charge needed around 940mAh, current 0.46A - 0.50A
The battery with lowest output voltage was 9.35V and the highest 9.55V.

Here is a photo of the circuit board located at the bottom of the battery.

The IC’s are (from left):
2YL6(UN8HX,G5242) - Charge management
XB5353A - Protection IC
UB6FA(SDB628) - Step Up Converter (On the rear side of the PCB there are 2 resistors that determines the output voltage - modding possibility!)

The reason for dismantling the battery was that after a resistance test with an iCharger 106B+, the battery output was only 1.9V as if the Step Up Converter was broken.
Eventually I found that the protection IC had just kicked in due to high current drain.
Connecting a charger to the USB input immediately reset the output voltage to normal.

I charged my battery and run it for more than 30 hours, and is still working in the instrument… And now i know that I can recharge it while it is running, wow.
I guess I am done looking for a perfect 9V battery.
Thanks HKJ!

Been looking for a rechargeable 9V that can hold load above 9V. This looks to be the perfect choice.

Thanks HKJ for your informative reviews! Always so helpful!

When i read the >3000 cycles i though they must be lifepo4 cells which can get >2000+ cycles if charge/discharged correctly, But if they use an 3.7v li-poly cells the >3000 cycles must be totally FAKE.

I have the AAA version of this battery.

John.

Recently picked up a pair of these 9V from Banggood.

sixty545, you mention the output voltage has possibility to be modded?
Could it be modded for higher output voltage, maybe 11-12V?

Sorry for the late answer!
According to the specs for SDB628 (step up converter) and alikes, it can output up to about 24V by selecting proper voltage divider. So the answer is yes, but available output current gets accordingly smaller.

Thanks for the info, much appreciated. If I could find someone here in the states to adjust these to 11-12v that would be great.

btw these things are worthless for use in a radio of any kind.
be it a vintage pocket radio or a wireless mic.
the rfi is off the scale bad.