Hey guys, I'm a new member to the forum (even though I've been using the forum for info for a while now) so I cannot post this in the appropriate area. But I've just had a unregulate dual 18650 MOSFET box hard short on me and I would like to resolder everything and get it working. The problem is that I'm unsure if the 2 MOSFET's in the box will still work properly if I do that.
New to form but I have a question about MOSFET's
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Hi and welcome to the board. Desolder the MOSFETs and test them. If you don't know how... let me suggest you'd be better off paying somebody who does to do the work for you. However, the number on the MOSFETs should yield a data sheet with a Google search and that will give you a wiring diagram. It also depends on how it shorted. If it shorted through the MOSFETs themselves, they're probably toast. What happened to it? You put the batteries in backwards?
IF you hook them back up correctly and do not overheat them while soldering and IF the short did not damage them you should be fine.
There most likely toast. You can test them but if it was more than a second there most likely gone. Im assuming you put the batteries in backwards.
I read the other part about the batteries. If it was just one you should be ok.
I read the other part about the batteries. If it was just one you should be ok.
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Did you put both batteries in backwards, or just one?
If both, the MOSFETs could be toast.
If one, your MOSFETs should OK as all the current flowed just from battery to battery.
If both, the MOSFETs could be toast.
If one, your MOSFETs should OK as all the current flowed just from battery to battery.
Thanks for the help everyone. I think I'll send it back and see what they have to say first. If they won't warranty it then I'll start soldering everying back up on it. It was one of their cosmetic defect boxes and was only $100 but its still something I'd like to have been able to use at least once haha. :/
If I remember correctly, reverse polarity dosnt effect parallel boxes, so most likely you went over the amp limit of the MOSFET? Can you post a pick of the boxes wiring, two MOSFETs in regards to one switch usually is a double safty precaution. If that's the case you might be able to just rewire It with the good one that's left. Please take all of this with a grain of salt.
Edit: Sorry, didn't see you sent it back. Long day at work.
Edit: Sorry, didn't see you sent it back. Long day at work.
Also there was no atty on it. I had just got home from work and opened the box. Then i grabbed my batteries popped them in with one in the wrong way and BAM, the connections turn cherry red so i threw it across the room. Luckily doing that jossled the batteries loose so there was no fire
If one battery is reversed the box might not be affected but the batteries most certainly will as they will be directly shorted together....ouch.
If both batteries are reversed then current flows backwards through the MOSFET's "body diode", whether the MOSFET is on or off. The body diode has a much larger voltage drop across it and current flowing through it will generate a lot more heat, typically, than when flowing in the other direction. That extra heating can fry the MOSFET... if the atty is connected, that is. If not, no worries. The current can't flow through the MOSFETs then.
Glad the batteries popped loose!
If there was no atty attached then there definitely was no current flowing through the MOSFETs. They should be OK.
My head hurts now, back too Google for another basic electronics refresh...If one battery is reversed the box might not be affected but the batteries most certainly will as they will be directly shorted together....ouch.
If both batteries are reversed then current flows backwards through the MOSFET's "body diode", whether the MOSFET is on or off. The body diode has a much larger voltage drop across it and current flowing through it will generate a lot more heat, typically, than when flowing in the other direction. That extra heating can fry the MOSFET... if the atty is connected, that is. If not, no worries. The current can't flow through the MOSFETs then.
Oops, sorry!
Reversed polarity across a MOSFET can easily fry it. As little as 3A for a IRLB3034.
Correct polarity across a MOSFET may fry it but only at high amps, over 25A for an IRLB3034.
Reversed polarity across a MOSFET can easily fry it. As little as 3A for a IRLB3034.
Correct polarity across a MOSFET may fry it but only at high amps, over 25A for an IRLB3034.
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