Powerboost 500C Overheating

[bssackma]

I am attempting to use a Powerboost 500C to power an Arduino Mega2560. I have soldered on a switch and a battery terminal to the board. For the most part it works fine...but on 1 in about 5 occasions when I turn on the switch to supply power to the Mega it will overheat and turn off (the element near the blue power light get VERY hot). Without changing or adjusting anything I can simply cycle the power and it wont overheat the next time I turn on the switch (so it seems unlikely to be a short). Also, the overheating never happens once the Mega is running...if I can get it to turn on...it will stay on indefinitely (also suggesting that its not a short). Any thoughts as to what might be happening. Is this a faulty board???

Thanks for any insight!

[Franklin97355]

Could you post clear, detailed pictures of your board and the connections to it? There should be no reason for this to go away with a power cycle.

[bssackma]

Thank you for the prompt reply. It will be a day or so before I can post pics. In the meantime can you tell me what this type of overheating might be symptomatic of (ie what is this functionality designed to protect against). Is it possible that the Mega is drawing too much current. My understanding is that Arduino boards were fundamentally limited in the amount of current they could draw no matter what project you might have hooked up. The power from the PowerBooster is being used to drive the Mega through the USB connection via a custom cable. Thanks again for your help.

[bssackma]

OK, this is very curious/frustrating. I purchased 3 of these boards...and the two that I have been working with behave in exactly the same way -- overheat every once and awhile...but not every time (often cycling power will remedy the situation). On each board I have soldered in the recommended switch and battery terminal (Fig 1-2). I have determined that the overheating will still happen even when no load is connected (Fig 3) -- just power and battery (there is no short downstream of the board). The charging circuity seems to work fine. It will charge...light will be yellow...then the light will turn green when charging is finished. I am running the 6600 mAh battery from Adafruit. Here is the curious thing. On all 3 boards...when I have them on the bench...absolutely nothing hooked up (just the bare boards sitting there) I can test for continuity across the 5V and GND pins (either the battery terminal screws or the pins along the side) and they will 'chirp' indicating a very brief connection -- almost as if there is a static discharge. If I test again immediately everything seems fine (no 'chirp'). However if I wait a few seconds 20-40 seconds and try it again...it will chirp again. I am working on a grounded ESD mat...I have tested these in different parts of the house with the same result. I am wondering if this could be a static-related issue which is why the overheating seems so intermittent. As I mentioned earlier on 2 of the boards I have already soldered in the switch and battery terminal...however on the 3rd board I had only installed the switch but removed it so that it would be a bare board again -- just as it was received from Adafruit. All 3 boards are behaving the same way. Are these simply faulty boards -- can they be replaced (provided the replacements dont suffer from the same problem)?

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[bssackma]

This problem seems similar to what is being described in this post (same component heating up before the board shuts down):

viewtopic.php?f=19&t=65031

Can someone please let me know how to proceed.

Thanks!

[adafruit_support_rick]

I'm investigating... Thanks for your patience!

[adafruit2]

hmm not sure what it is but we can certainly replace. email support@adafruit and ask for 2 more, we'll see if that helps!