The Motorola Droid Razr XT912 seems like a nice enough smartphone. Small, slim, with a carbon fiber back. Friend David bought it from, I think Canada Computers, refurbed. After using it for a while the battery life was reduced, then he used it as an MP3 player. In the end I received it and used it as a desk clock. Finally, it would no longer reboot, seemingly in a boot loop.
Long ago I had known that the battery was puffed, a good sign of a short in the LI-Ion battery. The flexible back was quite bowed. This Motorola Droid Razr owes nothing to anyone. Released in 2011 it is near 9 near years old, quite ancient for a smartphone. The OS was Android 2.3.5 (Gingerbread), upgradable to 4.1 (Jelly Bean), the web site says. I did not really pay attention when the phone worked, and now can’t reboot it. No matter, as it made for a nice digital clock.
The battery, EB20, even after it was plugged in and fully charged, would only last for 5 minutes. I guess that is what happens when you get old! I don’t think that all is lost. I could replace the battery for $18, but at this point in its life, this makes no sense. Tech is all about newer, and smartphones do not age well. I could try to power the phone with a DC power supply at 3.8v and see what happens, but really, there’s no point. At least with old desktop PCs you can rejuvenate them by throwing on some version of Linux.
I really don’t know about buying phones used. If batteries go bad, then there is a finite life for these products. As software changes this phone hardware cannot accommodate updates and is therefore junk. It is unfortunate, really, and very wasteful. Is this the price of progress?

Motorola Droid Razr XT912 smartphone, battery puffed, cannot power up, boot loop and therefore dead. Photo 1 by Don Tai
Opening up the back was a bit of a task. It was stuck on pretty good. I had to use a screwdriver to pry it open, but the plastic tabs held and did not break. The battery was stick in there securely with double sided tape. after removing the two torx screws for the battery, I still needed to pry the double sided tape up in order to remove the battery. The inside was really clean, and well designed. The sim card door just locks into two tabs for the back, so with the back off will separate from the phone.

Motorola Droid Razr XT912 smartphone, battery puffed, cannot power up, boot loop and therefore dead. Back open. Photo 2 by Don Tai

Motorola Droid Razr XT912 smartphone, battery puffed, cannot power up, boot loop and therefore dead. Back open, battery removed. Photo 3 by Don Tai
I had thought that the battery connector was broken, thus damaging the battery, as there was a faint dark line across the positive connector, but no, after removing the battery, the connector was fully intact.

Motorola Droid Razr XT912 smartphone, battery puffed, cannot power up, boot loop and therefore dead. Battery connectors. Photo 4 by Don Tai

Motorola Droid Razr XT912 smartphone, battery puffed, cannot power up, boot loop and therefore dead. Battery connectors, macro. Photo 5 by Don Tai

Motorola Droid Razr XT912 smartphone, battery puffed, cannot power up, boot loop and therefore dead. Fully puffed battery. Photo 6 by Don Tai