Screenshots of recent battery use

Thanks for the report! I informed the Firefox devs and they luckily detected this problem already and fixed it. But the fix will be coming in Fx 43. Which comes out December 14.

The fix is in: Bug 1194049 - NsdManager increases power consumption

You can also test out the Beta version which already has this fix: https://www.mozilla.org/en-US/firefox/channel/#beta

But you say you already tested beta and problem is still there. :(

There is a 2nd bug about this problem so keep your eye on it for updates: Bug 1215012 - mdnsd - Firefox Beta Android excessive battery usage

Beta still has the same problem as of yesterday. I have been in range of wifi with wifi ON everytime this process started.

Thanks for testing on beta again! At this point I'd uninstall Firefox and use another browser until this is fixed or downgrade to the version before this problem. Keep in mind the older version will be missing a few security patches.

If you do downgrade, I'd avoid visiting bank sites and other sites where your security might be at risk. Just to be safe. For normal browsing, it's fine. Avoid sketchy sites though. ;)

Link for Android (ARMv7, 3.0 Honeycomb and above) : https://archive.mozilla.org/pub/mobile/releases/41.0.2/android-api-11/en-US/fennec-41.0.2.en-US.android-arm.apk

Good news! The battery drain bug has been fixed in version 42.0.2! Please download Firefox for Android 42.0.2 from the Play store ASAP! :)

The new version with the fix was released on December 2, last Wednesday.