Melex 512E very slow up hill

[Jsmith522]

I recently purchased my first golf cart and had no idea what to look for. I ended up buying a 1996 Melex 512E. When I test drove it I was only on level ground. I took it home and driving around the neighborhood I realized it is very slow going up even slight hills. It does about 15 on straight away, 20 downhill, but coming up it does 5. I have a neighbor that has a brand new sat off batteries so we swapped them out fully charged thinking batteries were the issue. There was no difference in the speeds. I do not need it to be fast, but I feel like it should go better up a hill. Now the hill size does not seem to make a difference and it does not slow if the hill is longer or shorter. It stays a constant 5 mph. Does anyone know if this is just all the cart can do or something else I can look at? Also if this is as fast as the cart can go is there any simple modifications or swaps I can do to increase the up hill speed. Thanks for looking and your time.