My Kyocera SL400R Won't hold charge after Charging

SOURCE: battery life

I bought a few SL400R.. yes I think this is the best camera ever. The battery that came with the cameras always would last very short time, especially in cold weather. But when I ordered new ones online, these would last very long. The specs of the new batteries are the same as the original ones. Go figure. After that I ordered external charger too, so I dont need to use the camera's built-in charger. Works very well.

SOURCE: my camera won't charge

I have the same battery charging problem to my SL400, after I bought the new battery and tried, the situation was the same, then I suspect the battery contacts becuase the camera can work fine with the charger plug in. After I press the battery end with some pressure, the charging light returns, then I checked the contact inside the camera, I found no dirty on contacts but they all flat, it means the battery contacts are losen contact with the camera charging contact. After I carefully tilt each contact upwards a bit (about 2 mm) then let the contact returns to normal, it works. but I don't know how long I need this repeat job and has to be careful not too break the contact, I think the contact tension is getting old.