I have an HTC EVO V (Virgin Mobile's version of the EVO 3D). I've been using it with the original battery without problems since I bought it new, over a year-and-a-half ago. It has never been rooted. In recent months, the battery life has dropped off significantly, and the battery is slightly swollen in the center.
I couple of months ago, I bought an extended battery off Amazon. But when I installed the battery, the phone would not charge it. With the phone off and the charger connected, the red charging LED would come on for a few seconds, then would continuously alternate flashing between red and green (red, off, green, off, red, off, green, off...). I left it on the charger overnight, but it was still like that in the morning. I turned on the phone, disconnected the charger, and turned on the phone. The battery icon at the top bar was gray with an exclamation point. Going to Settings/Power, the Battery Status was "Unknown" but the Battery Level showed it was about half-charged (I believe this was the charge the new battery had from the factory). I connected the charger with the phone on. Once again, the battery charge LED flashed alternately between red and green; the battery status icon remained gray with an exclamation point.
I tried doing some research and read something about the phone possibly being "confused" by the different capacity and charge level of the extended battery. So I disconnected the charge cable and used the phone to discharge the new battery, hoping that would allow the phone to start with a new charge and "learn" the new capacity of this battery. That did not work: the phone still refused to charge the new battery. I tried two different cables with two different chargers. I also connected to my PC and the USB data link worked fine, but still no charging.
Now here's the interesting part: throughout my trials, I was able to swap back in my original battery at any time and the phone would immediately recognize it and start charging it (with the phone off or on). Everything was normal whenever I put in the old battery. So at this point, I figured the new extended battery was either defective or incompatible. I returned it and tried to find a local source to buy a new battery.
I could not find an HTC OEM battery, so I ordered a Lenmar replacement battery (standard size) from BestBuy. The Lenmar battery model number is CLZ458HT, with a rating of 3.7V 5.4Wh / 1450mAh. I put this battery in and experienced the exact same problems as described above. The phone refuses to charge the Lenmar battery, with the phone either off or on, and the Battery Status is still listed as "Unknown." However, the phone continues to charge and function properly whenever I put the original battery back in.
I desperately need a solution for this problem as the original battery won't even hold a charge for half a day anymore.