Why is my HTC Sensation battery charging so slow?

[AC Question]

Htc sensation battery

I have a question,i want to buy htc sensation,but the seller says it is charging very slow,and battery does not last long.

So the battery should be very bad,right ?
Or,there could be something wrong with the phone,
if the phone is charging,he shoud be ok,right ?
Can you please tell me something about it ?

 

[belodion]

Htc sensation battery

If the battery is charging slowly, it may be that the USB lead needs replacing, or that the phone's USB port connector is dirty or damaged.
If the battery discharges quickly in normal use, it is probably bad.
My knowledge of these things is limited, and there may be other explanations.