Apple or Android watch alone with Dexcom G6?

Here some findings from my project to setup the Unihertz Jelly Pro + SSW3 + xdrip
I bought the Jelly Pro and installed xdrip+. After some trial and error, I was able to receive the BG values from the Dexcom G6. So far so good. But I didn’t manage to get the Xdrip+ screen on the SSW3. But for now I leave it, because I am going to return the Jelly Pro to Amazon.de . Because after 2 days of testing I found out that the batteries of the Jelly Pro last for only half a day (If you don’t use it very much). I am going to buy an Android with al little bit more battery capacity. Anyone a suggestion for a good and small Android phone that has at least a day battery life?