Cart battery blew its top
 

I was driving in a 36v E-Z-Go on the flat parallel to 466 when there was a loud bang from under the seat and the cart lost power.

Looking under the seat, one of the terminals had exploded off a battery. The cable and terminal were very hot, but the battery wasn't.

What might cause this to happen, and are the other batteries at risk of doing the same?

They are Trojans, installed as a set four years ago.

Just yesterday I checked the batteries for water, tested pH and voltage, and all seemed well.

Thank you

That is caused by heat generated by a loose or coroded battery wire. The heat produced caused the lead to melt and under load explodes and breaks connection.
The best means of prevention for this matter is to occasionally after a moderate ride grasp each wire and check for high temp differences
From one to another, if higher heat is present and the terminals are tight replace that wire. Corrosion may be preasant within the wires insulation and may not be visible at the wire ends.

Thank you, Frank