Glo Battery problems - sideloaded epubs

Having ongoing issues with rapid battery depletion.

Returned a Glo purchased at Christmas due to this issue. Got a replacement, updated the firmware, and am again having problems. I might add that the sideloaded books on this device cause NO issues on my PRS-T1, nor my GF's Touch.

Here's a calendar of results:

- Fully charged reader on Jan 25 at 6:00 PM and put to sleep. Wireless is off.
- Jan 26 9:00 am 72%
- Jan 27 9:00 am 46%
- Jan 28 4:00 am – Please recharge...
- Jan 28 3:45 pm. Factory reset. Wireless off. Installed a free Kobo ebook (The -Jungle). Went to page 1 of the book and put the device to sleep.
- Jan 29 3:49 am – 96%
- Jan 30 3:54 am – 96%
No issues with this book from Kobo..

- Jan 30 3:00 pm – 96%. Recharged and sideloaded epub w/Calibre
- Jan 31 3:55 am - 100%. Loaded 3 more epubs w/Calibre
- Feb 1 4:00 am – 100%
- Feb 5 1:00 pm – Dead. Charged Touch and put same book on it as test. Changed to a different book then put to sleep
- Feb 6 4:00 am – 91%
- Feb 6 2:38 pm – Glo at 63%. Touch still at 100% after an hour of reading with same book.

It seems evident to me that this unit is having an issue with sideloaded epubs. Note that the same book on the Touch at the same time exhibited no issues. As well, there was NO reading done during this time with the Glo. It sat on a desk, and was only turned on to check battery life.

I'm at my wit's end. This is our 3rd Kobo, and we've had zero issues with the Kobo Wireless and Touch.

Battery issues seem to be a problem with some people, based on other threads. Any ideas as to what I should do? Maybe install an older firmware? Or just contact Kobo, again? Right now, it's a $130 paperweight. :(