Ugh!
After only a year or so of use, my cell phone’s bluetooth receiver (a Cardo Scala 500) is failing miserably. The battery runs down far too quickly, and it has an infuriating way of running down the battery of my cell phone during its own erratically short life.
I thought I had a bright idea this morning — “GET A NEW BATTERY FOR THE BLUETOOTH!”
Well, Doh!
This seemed like a no-brainer. But I didn’t see any information about the battery on the outside of the device, the case of which is held together by a single tiny phillips-head screw. Using a jeweler’s screwdriver, I removed the screw, then pried off the upper shell of the case. Much to my horror, there was no visible battery! Worse yet, the circuit board is solidly joined to the lower shell assembly, meaning that I’d have to break plastic and solder joints to free it, which I’m sure would render the thing inoperable (even assuming I could find and replace the battery).
I scouted around further, and discovered to my horror that many of these bluetooth devices do not contain replaceable batteries — meaning they are essentially throwaway devices which last for a year. This comment made me feel like a total idiot:

I can’t believe people are actually buying DISPOSABLE bluetooth devices. After one year of use, any battery out there will not hold the charge anymore.
There is no way to replace the battery inside those bluetooth devices. So you have to buy a new one.

While I should probably pay more attention to these things, there was nothing in the company’s product description that warned that the device was a throwaway, nor did I see any caveats in the standard reviews like this one indicating that when the battery gets tired, the whole unit becomes trash.
Well, at least the federal government won’t arrest me for throwing it away. Although I suppose if I put it within ten feet of my sudafed, I could be busted for running a meth lab.
Sigh.
Once again, mere life becomes a slippery slope into crime. Is it me, or is reality becoming surreal?
Anyway, after some looking, I did find this at the company’s FAQ:

The battery should only be removed by authorized personnel. You should never try to open the Headset and let only authorized Service Centers maintain or service your Headset or Adapter. Unauthorized opening of the product will void all warranties.

Whoa!
You mean, by taking out that screw and simply looking inside, I voided my warranty? How mean of them! I put it back together and it’s absolutely no different; the problem is that it’s only good for a couple of hours and the quality degrades very quickly. It’s obvious that the battery is defective, so how is it that I voided the warranty by simply taking a peek inside?
No need to panic. I just read through the manual (here in pdf), and on page 16 it states that the warranty is (meaning was) only good for one year!
And on page 17, the one year limited warranty clearly states that batteries are not covered!

Certain limited life components… such as…. batteries… are exempt from any warranty.

Great. So by opening the unit, I voided nothing. (Unless it’s possible to void a useless warranty I no longer have.)
Two important lessons here.
Caveat emptor.
And be careful having lithium batteries anywhere near sudafed!