I have the same device, with the same issues. I fixed the USB cable by using a needle (or other thin, hard object) to clean months of hard-packed lint out of th

I have the same device, with the same issues. I fixed the USB cable by using a needle (or other thin, hard object) to clean months of hard-packed lint out of the USB port. The cable now snaps in securely and charges reliably. You can also replace the battery for about $30, but expect a huge headache, cosmetic damage to the phone, and high risk of piercing/igniting the old battery. FWIW, I will never buy an Android phone again, but for another reason - privacy.