I got an electric 1999 club car and I got no power going up hills and

I had a 2002 Ez-Go for about 10 years. With relatively light usage, I only replaced the batteries once in that period. When the charge doesn't last long enough for you, it's time to get a new set of batteries. They generally must be replaced as a set, since unequal batteries will result in some being overcharged and some being undercharged. I bought mine from a local golf cart dealer.

More details!

(1) I was able to find free downloads of the Owners, Service, and Parts manuals. The service manual has a section on battery maintenance that is well worth reading.

(2) Check the level of the battery electrolyte periodically, fill with distilled water to about 1/4" below the vent ring. The level should never be low enough to expose the plates. I used a length of 1/4" PVC tubing to make a siphon from a gallon jug of distilled water, that made it much easier to fill correctly.

(3) The dealer suggested truck bed spray-on liner (from local auto parts store) as a coating for the metal parts supporting the batteries (first neutralize acid with baking soda and water). That worked well to reduce rust and corrosion.

(4) The charger uses a ferro-resonant transformer to regulate the charge voltage. The electrolytic capacitor connected to the transformer gets old and eventually fails (open circuit). I found a can-style film capacitor of the same value online (DigiKey or Mouser), it took a little trouble to rework the mounting clamp, but it should last forever.