Maker Pro
Maker Pro

blew out a battery capacity tester. where to start?

brandnewb

Nov 30, 2021
75
Joined
Nov 30, 2021
Messages
75
yeah the mosfet is blown. I watched a few videos on how to test a mosfet using a multimeter and now I know.

i'll test the other 2 components tomorrow
 

brandnewb

Nov 30, 2021
75
Joined
Nov 30, 2021
Messages
75
btw, this capactator tester can't handle anymore than 185 watts. If I get a bigger more badass mosfet can I then draw more power assuming it is only the mosfet that is blown?

My battery pack theoretically can deliver 48V * 280A = 13.44Kw. I'd love to run a cap test at that power and see if the pack can run for an hour before reaching 40V ;) And heat up the house for no good reason in the process ;)
 

brandnewb

Nov 30, 2021
75
Joined
Nov 30, 2021
Messages
75
If I get a bigger more badass mosfet can I then draw more power assuming it is only the mosfet that is blown?
yeah never mind, I figured after a good night sleep that I'll have to replace all the components along the whole path from the battery source leads + and - and get an insane 48V dc immersible heater. That is something for when I am a bit less newb ;)
 

H2814D

Nov 4, 2017
110
Joined
Nov 4, 2017
Messages
110
Just curious. Was that a hole in the back side of the IRFP260? You have it right side up in the picture now. I know you did say it was faulty already.
 

brandnewb

Nov 30, 2021
75
Joined
Nov 30, 2021
Messages
75
Just curious. Was that a hole in the back side of the IRFP260? You have it right side up in the picture now. I know you did say it was faulty already.
I must apologize but I really do not know. I am really new to electronics and everything related. Hopefully someone else knows
 

H2814D

Nov 4, 2017
110
Joined
Nov 4, 2017
Messages
110
I must apologize but I really do not know. I am really new to electronics and everything related. Hopefully someone else knows
Oh. I thought YOU were the one who had removed the component from the board. Am I mistaken? I had mentioned it in an earlier comment way up there somewhere. ^^^^^
 

brandnewb

Nov 30, 2021
75
Joined
Nov 30, 2021
Messages
75
yes I removed it, but one can desolder without knowledge of what the component is and how it works to be able to desolder it. and truth be told I did a sloppy job ;)
 

H2814D

Nov 4, 2017
110
Joined
Nov 4, 2017
Messages
110
yes I removed it, but one can desolder without knowledge of what the component is and how it works to be able to desolder it. and truth be told I did a sloppy job ;)
Oh, when I looked at the picture you supplied of the component off of the board, I thought you did fine. The board just needed a bit of cleanup and the new component would have soldered back in. No worries about the soldering though, we all had to learn how at some point. So are you going to try and source the components and replace them, or are you done with it now?
 

brandnewb

Nov 30, 2021
75
Joined
Nov 30, 2021
Messages
75
Oh, when I looked at the picture you supplied of the component off of the board, I thought you did fine. The board just needed a bit of cleanup and the new component would have soldered back in. No worries about the soldering though, we all had to learn how at some point. So are you going to try and source the components and replace them, or are you done with it now?
My best guess is that that hole aids in heat dissipation. And yes I will continue testing components and replace those that are blown
 

H2814D

Nov 4, 2017
110
Joined
Nov 4, 2017
Messages
110
My best guess is that that hole aids in heat dissipation. And yes I will continue testing components and replace those that are blown
The "hole" I am talking about appeared to be by the top most pin of the component in your first picture of the the then circled (squared) photo that was edited by someone else (Mr Kapp) up there ^^^. If you can take a close up pic of the larger of the three components (the IRFP260) of the back side (not the side with the component numbers/letters) and post it, maybe I can tell then.
 

Harald Kapp

Moderator
Moderator
Nov 17, 2011
12,612
Joined
Nov 17, 2011
Messages
12,612
I guess you are talking about different holes, are you?
@H2814D mentions the spot that is barely visible in your first picture in the top left corner of the mosfet. That one may, on closer inspection, be a hole in the case where excess heat punched the case to vent hot gases. One will need a close up to inspect that point in more detail.
@brandnewb mentions the big hole in the center of the mosfet's tab. That one is a mounting hole to secure the component to a heatsink by a screw.
 

H2814D

Nov 4, 2017
110
Joined
Nov 4, 2017
Messages
110
I guess you are talking about different holes, are you?
@H2814D mentions the spot that is barely visible in your first picture in the top left corner of the mosfet. That one may, on closer inspection, be a hole in the case where excess heat punched the case to vent hot gases. One will need a close up to inspect that point in more detail.
@brandnewb mentions the big hole in the center of the mosfet's tab. That one is a mounting hole to secure the component to a heatsink by a screw.
I agree. And that component is very easy to source, so I don't want him giving up too soon. :)
 

brandnewb

Nov 30, 2021
75
Joined
Nov 30, 2021
Messages
75
here are some closer ups

upload_2022-1-19_9-10-48.png

upload_2022-1-19_9-11-59.png
upload_2022-1-19_9-12-35.png
upload_2022-1-19_9-13-50.png
and I think I found trace evidence of the spark as there is some dark line where the mosfet used to be
upload_2022-1-19_9-14-51.png
 

brandnewb

Nov 30, 2021
75
Joined
Nov 30, 2021
Messages
75
can I post a link to what I bought or is that breaking forum rules? Anyway i'll list them for now
5Pcs--IRFZ44N--49A/55V
5Pcs--IRF510N--5.6A/100V
5Pcs--IRF520N--9.7A/100V
5Pcs--IRF530N--17A/100V
5Pcs--IRF540N--33A/100V
5Pcs--IRF640N--18A/200V
5Pcs--IRF740--10A/400V
5Pcs--IRF840--8A/500V
5Pcs--IRF3205--110A/55V

I've got half a mind to start with the IRF3205 lol. assuming the 2 schotkkies are still working perhaps I can then crank up the amps a bit more ;)

I did not find a IRF260 that would be here tomorrow so I am hoping I can use one of the above. Should the tester not show signs of life I'll start with the skotkkys to see if they might be blown as well.
 

brandnewb

Nov 30, 2021
75
Joined
Nov 30, 2021
Messages
75
I've got half a mind to start with the IRF3205 lol.
ahh no, that would fry things again as a fully charged battery bank is 58V. or is pushing the limit a bit by 3 volts something seasoned board builders do from time to time and get away with it?
 

Alec_t

Jul 7, 2015
3,212
Joined
Jul 7, 2015
Messages
3,212
is pushing the limit a bit by 3 volts something seasoned board builders do from time to time and get away with it?
Most seasoned board builders use components well within their ratings, for reliability.
 

H2814D

Nov 4, 2017
110
Joined
Nov 4, 2017
Messages
110
can I post a link to what I bought or is that breaking forum rules? Anyway i'll list them for now
5Pcs--IRFZ44N--49A/55V
5Pcs--IRF510N--5.6A/100V
5Pcs--IRF520N--9.7A/100V
5Pcs--IRF530N--17A/100V
5Pcs--IRF540N--33A/100V
5Pcs--IRF640N--18A/200V
5Pcs--IRF740--10A/400V
5Pcs--IRF840--8A/500V
5Pcs--IRF3205--110A/55V

I've got half a mind to start with the IRF3205 lol. assuming the 2 schotkkies are still working perhaps I can then crank up the amps a bit more ;)

I did not find a IRF260 that would be here tomorrow so I am hoping I can use one of the above. Should the tester not show signs of life I'll start with the skotkkys to see if they might be blown as well.
I think I would have replaced the component that tested bad with the same replacement to make sure the thing worked again, before I started messing with anything else. You do know the original was an "IRFP260," right? I haven't checked compatibility, but all of your components you listed are minus the "P".
 

brandnewb

Nov 30, 2021
75
Joined
Nov 30, 2021
Messages
75
Wow, thanks for pointing that out. I'll send those back and get the correct component. might take some time to get here.

and you're right, Experimenting can be done later
 
Top