PWM Issue

Hello,

I have some questions regarding the design of alt-nrg.org PWM. But before I do, let me describe my total setup.

1. 2006 Silverado 5.3l Gas
2. 21 Plate 6" Diamond shaped Cell.
3. Electrolyte is KOH, about 3 round table spoons per gallon of distilled water.
4. The above mix will draw about 45 amps on a straight DC, or with a PWM.
5. At 37 amps, straight DC or PWM, the lpm is about 2.1.
6. The 37 amps is while the truck is idle in the drive way, if I rev or drive around, the voltage regulator starts going nuts, voltage drops and current shoots up.
7. If I use a PWM, and limit it to 32 amps or below, the system is stable.
8. I guess my alternator/regulator can not handle the extra load.
9. At 32 amps, only get about 1.8lpm.
10. Bought a third party PWM, worked fine until I pushed it to hard. It was designed for 35 amps.
11. Decided to buy an already made PWM PC board that supports two Mosfets that is based on alt-nrg.org ZeroFossilFuel design. I added C5 and C7 capacitors, D1 and the two Mosfets in a larger aluminum case.
12. Bought an oscilloscope off of Ebay.
13. Set my new PWM at 2.5khz


Symptoms of this PWM.

1. The C7 12,000uf cap burst after about 20 minutes.
2. If I trim the Current Limit pot so that it is not current limiting, the voltage drop across D & S of the Mosfet is less than a volt. When I trim the pot to start limiting the current, the voltage drop across D & S of the Mosfets increase, which robs voltage from the cell. No current limit is about 45 amps, if I limit the current down to 30 amps, the voltage drop across D & S is 4.2 volts.
3. Before I hooked this PWM to my cell, I did a 12v light bulb test. Have two 12v lights bulbs that draw about 2.1 amps each. Attached the first bulb and set the limit to 1.2amps. Added a second bulb, the duty cycle did decrease, but the current still increased by .9 amps to a total of 2.1 amps.

Questions
1. What caused the C7 cap to over heat and burst?
2. Is this normal for the voltage across D & S of the Mosfet to increase?
3. Shouldn't the PWM keep the current at the already limited 1.2 amps when the load increases?


I know your time is valuable, and I would greatly appreciate any comments on how to solve this.

Thank you.