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I'm building a reverse polarity protection circuit using an N-channel MOSFET (see figure below)

Reverse Polarity Protection

For the battery I'll be using an 18650 cell which will range from 4.2 - 3.3V. The max discharge of my circuit will be about 10A. I'm currently looking at this MOSFET. The specs all seem to fall within my parameters but I have a feeling that there's no way a MOSFET this small could provide that much power; am I just over thinking this?

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  • \$\begingroup\$ insufficient details , not over-thinking, also duplicate question electronics.stackexchange.com/questions/34915/… \$\endgroup\$ Commented Apr 6, 2017 at 16:54
  • \$\begingroup\$ Max current implies you have massive heatsink. Do the thermal calculations with duty factor and Rja \$\endgroup\$ Commented Apr 6, 2017 at 16:57
  • \$\begingroup\$ Missing charger? which needs 2 FETs N,P, \$\endgroup\$ Commented Apr 6, 2017 at 17:19
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    \$\begingroup\$ Does FET Drain-Source look reversed to you? \$\endgroup\$ Commented Apr 6, 2017 at 17:34
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    \$\begingroup\$ The circuit is fine, but your choice of MOSFET isn't great - as Trevor's answer shows. You need something which turns on hard with very a low Vgs applied. \$\endgroup\$
    – brhans
    Commented Apr 6, 2017 at 17:38

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According to the safe operating DC operation curve you are right at the limit for 10A at 25C. So I'd say it's not going to work for you. Also at 3.3V the thing will be barely on. Even 4.2 it won't be saturated.

enter image description here

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