Fast discharge new 30xhs batteries -15 after 20 minutes of use

2002 e825
New Trojan 30xhs All batteries test good
New Super charger (ride4fun) programmed for lead acid

My battery guy already swapped out the batteries twice and the same thing is happening.

Starts at 100% stays there for a few miles, then starts dropping fast, in a few minutes the cart throws a -15, beeps and losses all power. Have to sit on the side of the road for about 15 minutes turn it back on and try to get home.

Is this a controller issue, is this a motor issue, because after two sets of brand new batteries I have to start believing it’s not the batteries and it’s not the brand new charger.