Had a similar issue on a galaxy s4 in cold weather (particularly when launching the camera app). The battery was ~3+ years old though. After doing several hour

Had a similar issue on a galaxy s4 in cold weather (particularly when launching the camera app). The battery was ~3+ years old though. After doing several hours research into buying a new phone (iphones and androids), I settled for now on upgrading the battery in my old phone to a larger 5200 mAh battery. It introduces a slight bulge, but after the first few weeks I've been extremely happy so far. The phone works 2 days under heavy use, 3+ under light use, and changed how I perceive it - essentially I don't think about charging during the day anymore, and don't worry about remembering to charge at night / while catching up on news in bed. My assumption is that this is a better solution because it's drawing current from more cells in parallel, meaning less strain on the battery itself (there's an equation for this, but basically more current on individual cells drains a battery's capacity exponentially faster). It's also one less thing to think about carrying compared to carrying a separate usb charger. I'm hoping there's still going to be phones with removable batteries to enable larger 3rd party ones to be installed, or that 'smart battery packs' on the iphone or moto z someday allow for current sharing between the internal+addon batteries.