iPad Air 2 (A1566) boot loop after full discharge.

I usually charge my iPad well before it's fully discharged but this time apparently some app kept the iPad running overnight so the next morning it was completely discharged. I connected it to a wall charger (about 1.5A max) and when it woke up, it was stuck in a boot loop. I left it on the charger overnight but the next morning it was still boot looping. I read on several pages that updating it through iTunes might fix it. But alas, briefly after it started updating, it rebooted it self and now it's stuck in recovery mode. So every time I power it on, it boots in recovery mode. A recovery (through iTunes) does not work either for the same reason the update failed: it reboots shortly after it starts the recovery process.

Now I'm pretty sure it constantly reboots because it never charges past the point where it is able to keep the iPad running. So the next thing I want to try, is to either charge the battery "myself", bypassing the iPad's own charging electronics. The onl problem is that you pretty much have to disassemble the entire iPad just to get at the battery's connector. I of course would like to avoid that.

Near the battery's connector, I see two test pads. I measure 2.2V across them. That seems awfully low for it to actually be the battery's + and - pins. I doubt that 2.2V is even enough for the iPad to start in recovery mode. But I am measuring with the battery still connected. So I don't know.

So I was wondering if anyone knows what those test pads actually are. Can I hook up a Li-Ion charger at those points to charge the battery?

Any help is appreciated.