I'm going to give this a shot, but I've been known to screw up these numbers as far as power over time ratings.
Being super lazy I used a calculator to get to:
2.2hp for 2 hours == 3.275Kwh. (This is purely Hp to Kwh, so theoretical.)
But I'd start by looking at the standard battery pack...
A typical 36v golf cart is what? a bank of 6, 6volt 240Ah flooded lead acids.
50% depth of discharge makes those effectively 120Ah.
Call that 6v*120ah*6 = 13,824wh or nearly 14Kwh of usable power.
That said, most people don't drive these carts until the battery is dead, this is just the total capacity of a typical cart.
Let's add in some more data eh? I found this when looking up discharge rates on carts and it seems pretty reasonable.
Five Star Golf Cars featuring new and used golf cars, rentals, services, and accessories in Queensbury, NY, Buzzard Bay, MA, Laconia, NH, and Windham, ME.
fivestargolfcars.com
"Another study done by the Toronto and Region Conservation Authority evaluated the energy use of electric golf carts per hour. The report indicated a 3.3 kWH for its daily energy consumption, while gas carts consumed much more at 1.13 L or 10 kWh of energy."
So yeah, now factor in that you'll drop weight off this thing by not using lead acid.
If you don't want to build your own pack, sure a 36v, 3kwh pack would be the minimum I'd start with. I think it may run up a bit short, but it depends on your driving habits.
For a diy build? I'd get a dozen lifepo4 cells (and don't forget a 36V lifepo4 BMS)
3.2v*12*100ah = 3.8Kwh
3.2v*12*120ah = 4.6Kwh
3.2v*12*200ah = 7.6Kwh
If you don't mind upping the voltage, I'd consider a 48v pack made up of 16 of whatever size you get.
Those cards appear to be belt drive, I'd look into installing a brushless motor and controller to really have something.
