Time for another try at a Znter rechargeable LiPo battery with USB port for charging in the form of a 9V 400 mAh battery as an alternative to traditional 8.4V NiMH or 9V Alkaline battery. With our initial bad experience with the 1500 mAh Znter ZNT18650 that came dead and after opening it up we were not that happy with the build. The 9V rechargeable battery from Znter however looked much more interesting as it actually comes with higher advertised capacity than pretty much all 8.4V NiMHs and falls a little short in capacity compared to the best 9V alkaline batteries in terms of mAh. It is most likely a single cell LiPo battery with a step up voltage converter to output 9V in the size of a standard 9V alkaline battery. Fortunately the 9V 400 mAh Znter battery we got was what it was supposed to be and not with a dead LiPo cell inside, so we headed to testing its capacity…


Doing our regular 0.05A test we use for the 9V Alkaline and 8.4V NiMH batteries we got 338 mAh out of the rated as 400 mAh Znter battery, a really good result compared to 8.4V NiMHs we have tested so far. That result is also on par with an average performing 9V alkaline battery, but the Znter can be recharged and reused via a standard USB, so it is much more convenient. Things however get even more interesting when we look at the voltage curve during the discharge tests as it is essentially flat up until the end of the available capacity and we do not normally see this with NiMH or Alkaline batteries, it is the expected behavior for power banks however. The pretty stable at 9.51V output during the whole discharge test means much higher capacity in Wh compared to traditional batteries with the same mAh results where the voltage is dropping during the cycle. As a result we can say that we are quite happy with this particular product from Znter and it can be a really good alternative to traditional 9V Alkaline and 8.4V NiMH batteries.

The performance of the 9V 400 mAh Znter USB Rechargeable LiPo Batteries in our tests:

– 338 mAh at 0.05A load

– 3.212 Wh at 0.05A load

Time to check out another power bank from Xiaomi, this time it is probably the most interesting product of this kind they are currently offering – the 10000 mAh Xiaomi Mi Power Bank Pro (PLM03ZM). It is a compact and nice looking power bank with aluminum case that features USB type-C charging port for faster charging of the power bank’s battery and supports up to 18W fast charging both ways. The power bank supports the Quick Charge 3.0 technology by Qualcom for faster charging of compatible smartphones and there is automatic smart voltage switching between 5V, 9V and 12V (depending on the device you connect) in order to reach up to 18W input and output if supported. Also the PLM03ZM apparently also supports HiSilicon’s Fast Charging Protocol used by Huawei, so compatible smartphones can also benefit from faster charging. Do note that there is a PLM01ZM version of that power bank that is a bit older and Quick Charge 2.0 and no support for HiSilicon’s Fast Charging, so make sure you heck the model number just to be sure you are getting the newer PLM03ZM version that we have tested.

10000 mAh Xiaomi Mi Power Bank Pro Specifications:
– Model: PLM03ZM
– Battery type: Lithium polymer battery
– Input voltage: 12V/9V/5V
– Output voltage: 12V/9V/5V
– Input current: 12V 1.5A/9V 2A/5V 2A
– Output current: 12V 1.5A/9V 2A/5V 2.4A
– Rated capacity: 3.85V/10000mAh
– Charging time: 3.5 hours (18W charger, standard USB cable), 5.5 hours (10W charger, standard USB cable)
– Dimensions: 128.5 x 75 x 12.6mm
– Load detection: Auto-detects device plug-in/plug-out
– Safety protection: Supports protection from over-voltage (input and output), over-current (input and output), short circuit, over-charge, over-discharge, and battery Positive Temperature Coefficient (PTC).
– Restoration protection: Wakes once plugged into charger
– Charging temperature: 0C-45C (TYP)
– Discharging temperature: -20C~+60C (TYP)
– Package contents: Power bank, User manual, USB data cable, Type-C adapter
– Weight: 223g


With the 10000 mAh Xiaomi Mi Power Bank Pro (PLM03ZM) we have performed two tests, one with with 1.0A constant current discharge and one with 2.4A as the maximum rating for the product for 5V. Since the power bank uses automatic smart switching between 5V, 9V and 12V if it detects a compatible device we were not able to test at the higher voltages unfortunately. Since we got really good results at 5V we expect that the performance with higher voltage and lower amps – 12V 1.5A and 9V 2A should also be really good. At over 7 Amps of usable capacity at both of our tests we can clearly say that the performance of the 10000 mAh Xiaomi Mi Power Bank Pro is really good, making the whole product a very nice overall choice for a mobile power bank with high capacity.

The performance of the 10000 mAh Xiaomi Mi Power Bank Pro in our tests:

– 7394 mAh at 1.0A load
– 7063 mAh at 2.4A load

– 36.92 Wh at 1.0A load
– 34.33 Wh at 2.4A load

The 16750 mAh ADATA P16750 Power Bank is another high-capacity mobile power bank from ADATA similar to the 20000 mAh P20000D model that we have recently tested, but not quite the same. The ADATA P16750 comes in a pretty compact size for its capacity, uses a nice-looking plastic case and comes with a power button and LED light indicator for the charge level. It has dual USB charging ports and can charge two devices simultaneously, but with a maximum total output of 2.1A for both ports. The input for charging the power bank is 5V/2.0A, so that the large battery capacity would not mean a day needed for a full charge at just 1.0A charge current, though you need to make sure you use a suitable power adapter. Just like its bigger brother the P20000D there is also a LED “flashlight” feature that we find useless, but other than that it seems like a really good power bank taking into account the specializations and features.

16750 mAh ADATA P16750 Power Bank Specifications:
– Capacity: 16750 mAh (Rechargeable Li-ion battery)
– Colors: Black / White
– Dimensions (L x W x H): 130.7 x 75.0 x 25.5mm / 5.1 x 2.9 x 1.0″
– Weight: 375g / 13.2oz
– Input: DC 5V/2.0A
– Output 1 & 2: DC 5V/2.1A max
– Accessories: Micro USB cable, user manual
– Warranty: 1 year


Let us take a look at the performance of the 16750 mAh ADATA P16750 Power Bank in our discharge tests trying to figure out what the usable capacity is. We see good and stable voltage curve during both 1.0A and 2.1A constant current loads with just a slight hitch at the end of the 2.1A discharge where we see a more significant drop for a bit before hitting the completely discharged state of the battery. In overall a good performance regarding the available capacity at both discharge currents we have tested, though it would’ve been better if the maximum combined output for the two charging USB ports was more than 2.1A for this high capacity power bank.

The performance of the 16750 mAh ADATA P16750 Power Bank in our tests:

– 11637 mAh at 1.0A load
– 10655 mAh at 2.1A load

– 55.33 Wh at 1.0A load
– 50.65 Wh at 2.1A load

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