I tried to do this procedure, but my HTC Desire 500 was restarting during this process.
I think there is wrong USB connector (in my case), because when I changed USB charger (SAMSUNG), charging worked. This SAMSUNG USB connector went to my phone much harder, then original one. So I think conntacts in my phone are wrong. When I tried to charged with my car charger it didnt work too...
http://www.ebay.com/itm/Light-Microphone-Flex-Cable-USB-Charger-Connector-For-HTC-Desire-500-5088-506e-/141401805059?pt=US_Cell_Phone_Replacement_Parts_Tools&hash=item20ec345103#ht_2126wt_1124
Once when I charged battery, battery was in gray color with exclamation (instead green) and LED was blinking not shining.
I have already changed this item (7months ago) because of microphone.