This guest review was written by Anthony Martino.
Up for review, we have a pair of aftermarket (third-party, generic, etc.) batteries and desktop charger for use with the HTC EVO 4G. I purchased them from eBay seller tuttoit, and they came packaged together for just $9.98, shipping included. Being that I've worked intimately with batteries of all sorts for the past couple years, I was curious as to whether or not these very inexpensive batteries could be worth even the pittance they were asking.
The package arrived from Hong Kong safely and about as quickly as one could hope. Inside were two loose batteries and a boxed desktop charger.
The battery labels say "replacement for HTC Touch Pro2," but the auction was listed specifically for the EVO. This is not uncommon, as a handset manufacturer often uses the same battery in a number of devices; the EVO can share a battery with the Touch Pro 2 (obviously), the Hero, and probably a couple others. The specs are listed as 3.7vDC (same as all modern cell phones) and 1500mAh, which is identical to that of the stock EVO battery. For those that do not know, the milliamp hour rating, abbreviated mAh, is the rating that tells us the overall capacity of a particular battery. The higher the number, the more work you can get out of the battery before it dies.
The charger is a simple, sturdy piece with a flip out plug, USB output, and charge indicator light. The main dock is rated at 350mA, plus or minus 50mA, which is somewhat odd to see. It's a relatively slow charge rate, with the average household charger putting out around a half amp (500mA) and the included EVO rated at a full amp (1000mA). The USB, conversely, is rated at 800mA.
I found the choices of color for the indicator a little odd, purple for charging and blue for charged, but they get the job done. Not much more to say except that it does what it's supposed to and that I tested the USB-out to make sure it worked to charge the EVO (with the EVO's included micro USB cord) while a spare was in the dock. I guess if space were at a premium on your power strip, that would be a nice feature.
Now the fun part.
I ran both batteries on a piece of equipment that we refer to as "the Cadex." What it does is charges them fully then discharges them at a user-specified rate and times how long it takes to deplete the battery.
I ran the first battery right out of the box at 750mA. It reached 89% of its advertised capacity on the first cycle, which is about 1300mAh. Not bad. The second battery received a charge on the desktop charger before the test, which was to test the charger more than anything. It was run through at a brisk 1500mA and finished at 87%, which again is just over 1300mAh. Usually we can get that number up just slightly on a second cycle, so they were run again, both at 1500mAh this time, and they reached 91 and 89 percent, respectively.
Finally confident that they wouldn't self-destruct in my precious phone, I tried them each out in the phone. They both powered it on without issue and ran the phone through a full day.
So, the deal that was too good to be true . . . for once, wasn't. It should be noted that I've been witness to several horror stories that involved these types of unknown batteries. Where I was apparently lucky, many have not been; their problems have ranged from the batteries just being incompatible to actually "venting" and damaging the device.
I would advise only buying from sellers with good feedback, and if you get a package deal with an external charger, use that for the battery's first charge and don't leave it unattended.
This guest review was written by Anthony Martino. All photos included in this review were taken with the HTC EVO 4G.