Each 8.4v battery is just under 9 pounds so all 48 are 432 pounds.
A stock 36v cart can get by with just 5 batteries and have near stock range. I intend on using 14 in my Yamaha for maximum Alltrax voltage and extreme range. With exception of mounting them, the only requirement is a special lithium charger. I use QC chargers, they are between $260-350 depending on voltage, mount on-board and are available in a lithium charge profile.
Here is a picture of 14 batteries in an ezgo txt I built to keep but I ended up selling it.