Is that petg? For some reason I usually have problems with petg and infill patterns that cross over itself so I usually switch to gyroid. I think it has something to do with the speed and flow and the properties of the filament that make it especially bad when the infill lines cross over itself. You can probably tune temps, speeds, and feeds to get it to work but I find it easier to just not use that infill pattern.
I concur about rechargeables - it doesn’t seem common for devices that take AA or AAA to have a battery gauge and it would be nice to be able to check the level on my rechargeables stock so I can know if I should top them off without needing to put each of them into the charger.