According to DIY Network, "Most extinguishers have a shelf life of five to seven years."

I would check the manufacturer's literature or web site to get specific information for the selected equipment and then err on the side of caution.

I'm glad that no serious damage happened. Even if the burning smell was brief, I think if it were me, I would still be pretty worried about finding the source. Actually, once I smelled it the second time, then I think I would really be interested in finding the source because then it wasn't just some one-time freak event.

I think maybe I'm a little more paranoid about fires lately, but more about fires outside my house. We had those terrible wildfires in Southern California last fall and I had to breathe smoke for a week, and then we had a small wildfire just a stone's throw from my own house not long ago (some kids had been smoking dope in the bushes) so whenever I smell smoke inside, I definitely go outside to see if the smell is out there.

I had an experience that has made me sensitive to burning smells as well. When I was about 13, there was an extension cord that was running under my bed that shorted out while I was asleep. I woke up to a burning, copper odor (like a hand full of pennies). I got up to check it out but the light wouldn't turn on in my room. My dad reset the tripped breaker and I saw sparks spew out from under the bed, bouncing off the blanket that had been covering me just a minute before. I'm certain that the circuit breaker saved me. The odor plus the sight of those sparks left a huge impression on me.

Decades later, I'm still hyper-sensitive to burning odors.

As I reflect on it, I'm not big on extension cords, either.

Yeah, or gang adapters that allow receptacles/circuits to be overloaded beyond one's wildest imagination.

What happened there? Do you think someone used the lantern as well as the Dot-It? If so, and if your son put it away knowing it was now dim, I'd have a word with him about it.

Or did the Lithium AA's under-perform? Or does the lantern draw a tiny amount of current even when off? I agree with the comments on rechargables (other than Li-Ion or Eneloops etc), but if Lithiums are failing we need to query Energizer.

I've been in the situation where I've prepared for power failure, finally got one, only to find my preparations didn't work. That's how I discovered tea-lights aren't as bright as proper candles. (This was back before LEDs.) It's galling, but educational. In theory, theory and practice are the same. In practice, they are different.

"...rechargeable batteries is not so useful in a power failure situation. The inconvenience of having to do reqular recharge, just seem too much of a hassle..."

Yup...

Rechargeables with a small solar recharger can be a nice thing.

John E

As others have said, the low-discharge type (eg Eneloops) seem to give the best of both worlds. You can stock-pile them fully-charged and they'll retain a usable charge for years (they lose about 15% in the first year, less there-after). And if the power cut extends indefinitely, you can recharge them by whatever means you can. Eg solar panels or car charger. Where-as with primary cells when you've used your stockpile, you're stuck.

Glad to hear that you survived OK and that it made you careful.
Good reason to allways keep a flashlight beside the bed.
Good reason to avoid extension cords (and if they cant be avoided, to use only reputable brands of heavy duty cord, #14 AWG)
And also a good reason to favour wool bed blankets over other materials, wool is naturaly non flammable unlike many other materials from which blankets are made.