DC Boost Converter Repair

[raf13005]

Hi Everyone, I am building a secondary battery system to charge my main hybrid battery while i am driving (2006 insight).

I am using two isolated battery packs to power two non-isolated 1.5kW boost converters wired in series (Any thoughts on this approach?). Anyways i accidentally reversed the input polarity to one of the boost converters and a chip exploded ...

Unfortunately for some reason this chip and the main controller IC are defaced so there is no visible part number. It would be really nice if anyone recognized what the broken chip might be?

In the pictures the chip that is damaged is U3. The first 4 pins of the chip are attached to the negative of the input capacitor bank. pin 6 is attached to a small inductor, tiny surface mount cap, and a diode, pin 5 is attached through a via to the positive rail of the input capacitor bank. The chip labeled U2 is a lm358 op-amp maybe used for CCCV regulation or  possibly temp monitoring.

There is a NCE 80h16 mosfet directly under the board. I am wondering if the mosfet, inductor, electrolytic capacitor, D5, and the broken IC make up a buck circuit for the fan to run?

I assume the chip covered under the white glue is a dc-dc boost converter management IC...

Anyways I am mostly hoping someone will know of any common chips that could have 4 pins wired together that could be used in dc boost converter management circuit.

the board is only 25$ but seems like a waste to throw it out if just one tiny IC is broken...

This board btw. http://www.ebay.com/itm/like/131945193257?lpid=82&chn=ps&ul_noapp=true