Monday, December 10, 2018

When 10-Year Batteries Aren't

The battery on the First Alert smoke detector advertises itself as having a 10-year life from date of activation.

This is handy as you can install it and not have to bother changing the batteries every time change twice a year as you do with your other smoke alarms and primary defensive weapon lights (you do do that, don't you?).

Well advertised 10 year lithium battery life didn't quite match real-life experience.

With the alarm having a manufacturing date of 2014 Sep 17 and it was installed in January 2015, it began to chirp with a low battery warning this month, for an in use life of almost four years. The chirp was pretty darn annoying, rather hard to track down as it was intermittent, and was puzzling as again, not 10 years.

On the plus side, First Alert stepped up and is replacing it for free with no shipping cost so they do stand by their product and offer great customer service. We'll see how long the replacement lasts.

2 comments:

Douglas2 said...

I can go through hundreds of batteries in a week, and depending upon the batch I will get from 0 to 7 premature failures per hundred. I regularly re-battery a form of instrumentation that we use, in this case with alkaline rather than lithium disposables, but I'm sure that there are still manufacturing defects even with the different battery tech. Most failures are within an hour, but we're drawing pretty high current from them, and can see a crude 3-segment LCD display of remaining life

It is for this reason that I won't, for example, rely on a battery thermostat to keep the furnace operational when we are away from home for an extended time in sub-freezing weather. I see batteries all the time that one day have an indication of lots of life left, and the next day they have no output, while the surrounding instruments are still fine with batteries from the same batch installed at the same time.

So I guess I don't see it as at all unusual that a consumer battery product produced by the millions with a design MTBF in excess of 10 years will have the odd unit that doesn't make it to 5, or that the manufacturer will quickly replace it with little hassle. It is to their benefit to get notice of such premature failures, so if the pattern looks too large they can start preparing for the inevitable product recall.

drjim said...

The people we bought this place from had to add some CO2 monitors (in a house with NO natural gas!) to meet code, and the ones they bought were the "10 year" combination CO2/Smoke alarm. I'll be watching these to see if they flake out in a few years.