Broken Fuel Gauge?

#1

Curious to know if anyone has any thoughts on this. Any help would be appreciated!

Recently I attempted to read the BLE configuration data from an NFC device (one of those radio/bluetooth speaker deals that are commonly in hotels). Turns out that the device not only has NFC, but wireless charging as well. When I attempted to interact with the device via NFC, I think I inadvertently triggered something in the wireless charging feature, since my Flipper instantly rebooted with some LED flashes as I recall, and after rebooting it registered 0% battery charge. Ever since, I am unable to charge the Flipper past ~70% (according to fuel gauge), and charging to that level takes quite a while (>day).

I assume that I the wireless charger pumped current into the NFC antenna or something similar which fried or otherwise disrupted some component. Have tried reflashing firmware, etc to no avail. Any ideas?

#2

bro :skull::skull: the low frequency antenna is highly susceptible to QI chargers. you just blew up your flipper

#3

Haha, well thanks for validating my thinking. To be honest I was shocked it didn’t do catastrophic damage. So far only seems to have messed with the charging circuitry which is not a deal breaker.

I’m going to crack the Flipper open today and probe around, but lesson learned!

#4

Hm, we’ve recently tested the flipper with Qi wireless charger and couldn’t damage it in any way, so I think it’s just a coincidence.

What’s more likely is that the battery power connector has come loose and that made the gauge go crazy. You’ll need to try and reconnect it, you can find the steps here. You need to do steps 1-4 and 7-9.

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#5

I was (and still am) skeptical of it being a coincidence, BUT looks like I may have been wrong, which would be great news. After disconnecting and reconnecting the battery, the fuel gauge looks to be reporting the proper level. Prior to this it was reading 95% on a battery with ~3.6v, now it is reading a more believable 19%, The charge current also seems to be a couple orders of magnitude higher than before now that it is registering the battery as empty. If the battery charges to 100% with voltage to match, then this really did solve the issue for me and I’ll be a happy camper :slight_smile:

Will report back after a bit.

P.S.: The battery connector does seem to be super touchy, which seems to be a known issue. I had to bend the battery cables into a flat position to keep some constant pressure on the connector otherwise it the device would power cycle with even a super light touch of the cable.

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#6

That looks to have fixed it. Charged back up to 100%/4.2V and everything looks normal. Thanks for the assist!

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#7