New Trent IMP120D iCarrier 12000mAh Heavy Duty 2A/1A Dual USB Ports Portable Charger Review
Up for testing is the New Trent IMP120D 12000mAh portable charger. In this, and my other reviews, I test the battery with a CBA-IV battery analyzer, and post the chart along with any other useful information here. The test results are presented in two parts: a png chart, and a PDF printout with text information too.
More information about how I conduct testing is available here. I also update the Facebook page dedicated to reviews at http://www.facebook.com/batteryreviews.
I got this New Trent IMP120D 12000mAh portable charger from Amazon on 11/27/2012 for $53.95. It must have been a special, because the price is now around $75 (12/14/2012).
The charger has 2 USB port outputs, #1 is rated for 1A (good for a phone, and other smaller electronic devices), and #2 is rated for 2.1A (good for Galaxy Note 2, iPad, tablets, other large devices).
I tested the New Trent IMP120D portable battery charger at 1A and 2.1A loads, the two advertised maximum and real-world loads.
Capacity: The capacity of the charger’s internal cells is 12000mAh @ 3.7V which is 44.4Wh of power. At 90% conversion efficiency, I would expect to see 39.96Wh from the USB port, which comes to about 7760mAh. When the converter efficiency isn’t specified, I assume 90% based on previous tests.
Voltage stability: The USB output voltage is about 5.3V when unloaded, 5.15V at 1000mA, and varies between 4.95V to 4.45V at 2100mAh. The 1000mA load voltage is within the USB specification’s 5% tolerance, but the IMP120D does not handle 2100mAh very gracefully.
With a 2100mAh load, voltage goes out of USB spec and is inconsistent compared to a 1000mA load.
Results: With a 1000mA load, the tested output is 39.56Wh (7690mAh) which is about 99% of the expected 39.96Wh (7760mAh). At 2100mAh, the tested output is 36.76Wh (7950mAh). This is about 92% of the expected 39.96Wh (7760mAh).
Bottom line: The result of the 1A test is as good as can be hoped for; less capacity when charging at 2.1A is expected, but the out of spec voltage might put more stress on whatever device it is charging. A phone or tablet converts the 5V USB input to the necessary internal voltage. If the converter is meant to run at 5V, running it at a lower voltage (like what the 2A port gives) will require the converter try harder to power the device. The result of this is heat, lowered efficiency, and possible equipment malfunction or shutdown from insufficient voltage.
1000mA load: 39.56Wh (7690mAh) out of 39.96Wh is 98.9%
2100mA load: 36.76Wh (7950mAh) out of 39.96Wh is 91.9%
In the chart below, the 1A and 2A test results are shown. The straight line is the 1A result, and the squiggly line is the 2A result. The squiggly line result at 2A shows that the New Trent IMP120D is not suitable to charge a phone or tablet at 2A.
Verdict for the New Trent IMP120D: not recommended.
The New Trent IMP120D appears perfectly adequate to charge at 1A (with USB Output #1), but is unable to deliver the same quality of power at 2.1A. I would not use the 2.1Ah output unless absolutely necessary. My recommendation may change as I get more information in future tests, but as I see things now, I rate it: not recommended.
Review by: Andrew Heyn