Lenovo is not know much for its mobile accessories an they have never been a focus of the company, but still it is making them as a part of their mobile accessories product lines. We have picked up one of the company’s power banks to check it out and it does not seem bad at all both in terms of specifications (See below) and features. The PB420 Power Bank is compact in size device with aluminum and plastic case, a single USB output and single micro USB input port and a LED charging indicator. The device looks and feels nice in overall and seems to be durable, though we have not specifically tested it out for durability. Even though it is using just 5000 mAh LiPo battery inside it can take a charge with 1.5A current and can output up to 2.1A for charging other mobile devices.

5000 mAh Lenovo PB420 Power Bank Specifications:
– Battery Power Capacity: 5000 mAh, 3.8 V
– Life Cycle: >300 Cycles
– Battery Cell: Polymer Battery
– Input: Micro USB 5 V / 1.5 A
– Output: USB Port 5 V / 2.1 A
– Cell Package: Single Cell – 1P1S
– Dimensions (W x D x H): 119 x 66 x 8.9 mm, 4.7″ x 2.6″ x 0.4″ inches
– Weight: Starting at 0.3 lbs (150 g)
– Colors: Black, Silver


We have tested the 5000 mAh Lenovo PB420 Power Bank with 1.0A constant current discharge and with 2.1A as well and in both cases the useable capacity in mAh is pretty high. Thanks to the high voltage output that stays close to 5V and does not drop much even at 2.1A load (~4.87V average) the capacity in Wh also is pretty high for a 5000 mAh power bank. What was a bit unexpected was the fact that the battery case gets a bit hot during higher current discharge which we did not expect to see happening with a power bank. Using a Lithium-Polymer battery cell with just 2.1A normally should not lead to the battery getting hotter, but the temperature is well within the problem-free zone and it does not seem to affect functionality in any way, so it should not be a problem. We should also note that so far this is the best 5000 mAh power bank in terms of useable capacity that we have tested so far, though we have just tested a few so far and we need to get more results for a proper comparison.

The performance of the 5000 mAh Lenovo PB420 Power Bank in our tests:

– 3571 mAh at 1.0A load
– 3234 mAh at 2.1A load

– 17.75 Wh at 1.0A load
– 15.72 Wh at 2.1A load

An interesting product from Energizer in the form of rechargeable AAA NiMH batteries that is apparently made wit 4% recycled batteries and that is a world’s first according to Energizer. The 1.2V AAA 800 mAh Energizer Accu Recharge Extreme NiMH come pre-charged and are of the low self discharge with charge lasting up to 12 months in storage. Marketing aside these do seem to be quite good for a mid-range in terms of capacity where higher current may be required and not so favorable temperature conditions are present.


The 1.2V AAA 800 mAh Energizer Accu Recharge Extreme NiMH batteries do manage to show pretty good results in our tests, though at 0.1A (our lowest constant current test setting) they fall somewhat short of the 800 mAh rating. Looking at the numbers and the discharge curves however you can see that increasing the discharge load all the way up to 1.0A the drop in the available capacity is relatively slow, so apparently these can handle higher current requirements pretty well indeed.

The performance of the 1.2V AAA 800 mAh Energizer Accu Recharge Extreme NiMH batteries in our tests:

– 732 mAh at 0.1A load
– 719 mAh at 0.2A load
– 713 mAh at 0.5A load
– 684 mAh at 1.0A load

– 0.931 Wh at 0.1A load
– 0.905 Wh at 0.2A load
– 0.871 Wh at 0.5A load
– 0.805 Wh at 1.0A load

We have picked up a 8.4V Duracell Recharge Ultra NiMH battery rated at 170 mAh capacity to test out and compare with other batteries of this type we have already tested. The 8.4V NiMH category is still not well represented in our tests, so we are trying to fix that by adding more batteries to test, but it will take some more time. The 170 mAh capacity is lower than anything we have tested so far, there are alternatives available with higher capacity available on the market than what Duracell is offering with this product.


We are doing our regular 0.05A constant current discharge test for this type of batteries with a cut-off voltage set a 7V to check the usable capacity in mAh and Wh that the 8.4V 170 mAh Duracell Recharge Ultra NiMH battery can actually deliver. We got 158 mAh as usable capacity in our tests and while it is a bit short of the rated capacity it is not that bad, the result however shows that this particular battery might not do that well when used in more power demanding applications.

The performance of the 8.4V 170 mAh Duracell Recharge Ultra NiMH Batteries in our tests:

– 158 mAh at 0.05A load

– 1.384 Wh at 0.05A load

To check the technical specifications of the 8.4V 170 mAh Duracell Recharge Ultra battery…

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