So this started a few months ago. When by battery would get to about 12% the phone would go into a boot loop. If I plugged the phone in, it would boot fine and stay on. Once I got the charge to around 15% or higher I could take it off the charger and use it until it got down to 12% again, then another boot loop. Presently it's now boot looping at around 25% battery life. My wife also has an S5 and it's updated to the latest firmware (as is mine), so last night I noticed her battery was at 8%. Mine was in it's boot loop having hit 22%, so I swapped the batteries. Her phone (with my battery) booted up fine and stayed on showing 22% life. My phone (with her battery) booted up, chirped that the battery was low and then went into the boot loop. So it would seem it has something to do with the phone. The phone is no longer under warranty, and actually we are about to hit our 2 years with them, so they'll be paid off and we are planning on upgrading. But I do want to keep this phone for a backup, so I would *like* to get this fixed, if the fix is free, he he. Thanks. I did find another post about a similar issue here: Dead battery causes boot loop? but it's for a different phone, and my problem seems to be with my phone, not the battery.