[brian_]

There's nothing silly about the question.

Automotive lithium-ion batteries can routinely handle about 3 A of discharge for each Ah of capacity, and even more very briefly, so to handle about 300 A of discharge you would need about 100 Ah of capacity. More wouldn't hurt, of course.

100 Ah @ 72 V would be 7.2 kWh. That sounds reasonable for a golf cart, although of course this style of "golf cart" isn't typically used for golf, and capacity depends on how it is used. Again, more capacity is good.

For those who didn't recognize "BBB Recoil", that's the Recoil model of the Bad Boy Buggies line, which is (or was) part of the E-Z-Go division of Textron. Stock, it appears to use nine 8 V golf cart batteries, which are typically rated at 100 Ah to 200 Ah, depending on the rate of discharge; lithium-ion batteries (even LiFePO4) can handle higher sustained discharge rates and deeper (to a lower state of charge) discharge than lead-acid, so the comparison is reasonable.

 

[brian_]

Obviously the range requirement determines the minimum energy content. Amp-hour capacity is irrelevant to energy without voltage for context, but yes, given a fixed voltage energy is proportional to amp-hour charge capacity.

Since this is an existing operational vehicle with no change being made in anything other than the battery, energy capacity (or amp-hour charge capacity for the same voltage) can be determined in relation to what it already has - want the same range, need the same capacity...