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A different battery fried my M4 board… why?
Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.

A different battery fried my M4 board… why?

by dbanks6990 on Mon Oct 18, 2021 6:14 pm

Hello,
I recently pitched my first feather M4 express board. I needed a smaller battery so I went to my local hobby shop. I double checked the voltage requirements on the M4 documentation and all.

I attached a battery (see attached) to my Feather M4 express board and it immediately started to smoke. I unplugged it quickly. But now my board is not working.

I don’t understand exactly what happened as the battery I plugged in seemingly is the correct voltage and specs.

B8A875AC-96AA-4FC5-BF4E-04FD4A0B033B.jpeg
This is the battery I attached to the board
B8A875AC-96AA-4FC5-BF4E-04FD4A0B033B.jpeg (101.17 KiB) Viewed 137 times


Am I wrong? Thank you for your help.

dbanks6990
 
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Re: A different battery fried my M4 board… why?

by adafruit_support_bill on Mon Oct 18, 2021 6:39 pm

We can't see the JST connector for your battery in the photo. But there are some batteries out there that are wired with reverse polarity to the ones we carry. reversed polarity would definitely cause damage to the battery charge controller. In some cases, the damage is limited to the charge controller chip. It may still be possible to use the board powered via USB.

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Re: A different battery fried my M4 board… why?

by dbanks6990 on Mon Oct 18, 2021 6:47 pm

adafruit_support_bill wrote:It may still be possible to use the board powered via USB.

Unfortunately the usb isn’t powering the board any longer either.

Do you know how to tell if the battery is wired in a reverse polarity?

dbanks6990
 
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Joined: Mon Oct 18, 2021 6:04 pm

Re: A different battery fried my M4 board… why?

by adafruit_support_bill on Mon Oct 18, 2021 7:06 pm

Post a clear photo showing the JST connector and the wires coming into it.

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Re: A different battery fried my M4 board… why?

by dbanks6990 on Mon Oct 18, 2021 7:35 pm

adafruit_support_bill wrote:Post a clear photo showing the JST connector and the wires coming into it.

This is all it is. Not sure it gives what you are looking for.
Attachments
E9403560-820F-4ED3-B851-1EFF1600A0F1.jpeg
E9403560-820F-4ED3-B851-1EFF1600A0F1.jpeg (206.49 KiB) Viewed 125 times

dbanks6990
 
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Re: A different battery fried my M4 board… why?

by adafruit_support_bill on Mon Oct 18, 2021 7:40 pm

That really doesn't show us whet we need to see. Most batteries have red and black wires going to the JST. Red for positive and black for negative. As you see in the photo below, the negative side is closest to the USB connector when plugged in.

Since there are no wires, to determine the polarity of that battery, you would need to test the pins of the JST with a multimeter.

Image

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Please be positive and constructive with your questions and comments.