I have a ~10 year old Watts Premier Reverse Osmosis water system in my kitchen. The faucet has a battery in it. The original battery tray is hard to remove, is white, and is ugly. After years of using a screwdriver to remove and replace it, it looked awful. So I designed a new one and used silver colored PLA filament to more closely match the look of the faucet. I also added a small handle with a grip on it to easily remove and replace the tray. The new tray is also 0.5mm more narrow vs. the old so it moves more freely, yet still stays in place.
I designed this tray specific to the faucet I have, so make sure it will fit yours.