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I want to add to this famous single cell lithium ion battery charging module a reverse voltage protection:

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I ended up with the following circuit (Load draws up to 700mA):

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Sorry, updated:

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My question(s):

  1. Is this already enough, or should I add a zener-diode/transistor etc (if yes which one - smd preferred)?
  2. Is this one p-channel mosfet able to switch fully on, even when the battery is almost empty (2.9V) or would another fit to this circuit better - smd preferred?

I've found a lot of solutions out there, but either for 12V-stuff or oversized.

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Is this already enough, or should I add a zener-diode/transistor etc

It would be enough if you had the FET wired correctly. You need to swap the Source and Drain so the body diode doesn't conduct with reverse battery polarity.

Is this one p-channel mosfet able to switch fully on, even when the battery is almost empty (2.9V)

Yes. But you know this already because you read the datasheet, right?

enter image description here

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  • \$\begingroup\$ Okay, thank you. It is a very important topic, hence I just wanted to get a third opinion, based on my guesses. Or eventually I just missed something else, which is important to consider, that's why I asked. \$\endgroup\$
    – playmobox
    Jan 13 at 15:05

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