First, cell phones usually have only one battery ,or at least we refer to it as one thing, so you wouldn't use the plural "batteries." Other things, however, could have multiple batteries.
1. No - My phone's battery is low.
3. My phone battery (or phone's battery) is low.
5. My phone needs to recharge.
7. No - You could probably say 'My phone is running out of battery.' (battery power is implied)