First off Club Cars do slow down up hills, to what degree depends on state of charge in battery pack and the motor/controller combination.
When you say the charger 'never shuts off', what is never, have you let it run overnight? It should shut off by itself.
On the gauge above:
- the needle will be pegged to thr right when charging
- a fully charged cart (charger shuts off) will point to the 'H'
- the 'F' line represents about 48 volts. This line is important. When the needle is to the left of the 'F' line WHEN THE CART IS SITTING IDLE, I figure I have used about half of the pack. Since I own the pack and do not wish to discharge too deeply, I would like to be home by then. As a rental I would not sorry so much <grin>
- If you are crusing along (not climbing hills) and the needle is less than half way into the green, get home soon

hope that helps...I have to run so maybe some typos or dumbos