Crossposted from Reddit /r/OpenPV
So, I'm trying to figure out if I bought the wrong FET, or if I got hornswoggled on Amazon.
I bought 2 of these: http://www.amazon.com/gp/product/B00HR6B8XI
Using this wiring diagram: http://i.imgur.com/40MQzQ4.jpg
This was built in a Hammond 1591BSBK with a 7.4v Turnigy 90C 2S Lipo pack. When testing it, I did about 3 pulses and all was good. I hit the button again for about a second, and it never shut off. Flipping the switch did nothing (which tells me I should probably move the shutoff switch to the battery negative). Had to disconnect the battery. Both FETs fried that way. Luckily, I hadn't packed anything into the box yet, where the battery + and - wires would be more difficult to get to, and the heat from the FET would damage (possibly dangerously) the Lipo pack.
Both FETs are stamped different (I'd take pictures, but my phone was just stolen). One has:
IRF4905
IR512P
5D4E
The other has:
IRF4905
IR1012P
1TA6
I'm not sure if I got jipped, or I just ordered the wrong FETs. I guess that's the risk you take with buying from Amazon instead of Digikey. Even though I was under the 55V / 75A / 200W limit, they still burned out (current built 0.37Ω, battery was at 8.04V when this happened, not counting the sag). I could see maybe 1 faulty one, but 2 in a row? The odds of that rules out manufacturer error, IMO.
So, can anybody recommend a good P channel MOSFET that can handle an 8.4v Lipo pack with builds no less than 0.2Ω (but averaging between 0.3 and 0.4)? I thought I had a good one picked out, but after 2 fried in the same way, it doesn't seem likely.
So, I'm trying to figure out if I bought the wrong FET, or if I got hornswoggled on Amazon.
I bought 2 of these: http://www.amazon.com/gp/product/B00HR6B8XI
Using this wiring diagram: http://i.imgur.com/40MQzQ4.jpg
This was built in a Hammond 1591BSBK with a 7.4v Turnigy 90C 2S Lipo pack. When testing it, I did about 3 pulses and all was good. I hit the button again for about a second, and it never shut off. Flipping the switch did nothing (which tells me I should probably move the shutoff switch to the battery negative). Had to disconnect the battery. Both FETs fried that way. Luckily, I hadn't packed anything into the box yet, where the battery + and - wires would be more difficult to get to, and the heat from the FET would damage (possibly dangerously) the Lipo pack.
Both FETs are stamped different (I'd take pictures, but my phone was just stolen). One has:
IRF4905
IR512P
5D4E
The other has:
IRF4905
IR1012P
1TA6
I'm not sure if I got jipped, or I just ordered the wrong FETs. I guess that's the risk you take with buying from Amazon instead of Digikey. Even though I was under the 55V / 75A / 200W limit, they still burned out (current built 0.37Ω, battery was at 8.04V when this happened, not counting the sag). I could see maybe 1 faulty one, but 2 in a row? The odds of that rules out manufacturer error, IMO.
So, can anybody recommend a good P channel MOSFET that can handle an 8.4v Lipo pack with builds no less than 0.2Ω (but averaging between 0.3 and 0.4)? I thought I had a good one picked out, but after 2 fried in the same way, it doesn't seem likely.
