If the intent is to drive the MOSFET directly with a logic signal (5V), that could be an issue with the IRF830, it may not turn on fully. The datasheet specifies VGS = 10V in the test conditions. Might be better to find a "logic level" MOSFET, typically these will specify VGS ? 5V. Just as one example that I've played with a bit, check out the IRLB8743.
OTOH, since 12V is available, the IRF830 gates could be driven by the 12V through some small BJTs.