Q1 in the circuit is not the major heat producer, it's Q2. I can only drop the voltage on Q2 by 1.5V. If I go any lower the battery will not charge.
I tried switching out the transformer with a transformer with a lower output, the first on (24V) got extreemly hot and now has an output voltage of 18V. My highest current transformer (15V) was unable to supply the voltage needed by the circuit. I went back to the 33V transformer, and everything works just fine again.