Where can I get a 20 year battery?
LoopyByteloose
Posts: 12,537
That's right, I want a battery that will hold its charge and provide continuous service over a period of 20 years.
Why so? I went to Microchip to review some information about their cheapest PICs and they claim that some of them can run for 20 years on one battery. That sounds excellent, but as I recall, the chemical nature of batteries is that they have a shelf-life with a complete charge that is far, far less that 20 years. And in many cases, they chemically fail in 3-5 years to be of any further use.
Lithium batteries are great for fast recharge, but don't hold a charge very long. And lithium may last longer than the 5 years, but I don't know a battery maker out there that really wants to sell anyone a battery that doesn't require replacement far more frequently than 20 years. After all, waiting for the next sale could be quite a bit dire. (And I think the space program uses fuel cells, not batteries.)
Why so? I went to Microchip to review some information about their cheapest PICs and they claim that some of them can run for 20 years on one battery. That sounds excellent, but as I recall, the chemical nature of batteries is that they have a shelf-life with a complete charge that is far, far less that 20 years. And in many cases, they chemically fail in 3-5 years to be of any further use.
Lithium batteries are great for fast recharge, but don't hold a charge very long. And lithium may last longer than the 5 years, but I don't know a battery maker out there that really wants to sell anyone a battery that doesn't require replacement far more frequently than 20 years. After all, waiting for the next sale could be quite a bit dire. (And I think the space program uses fuel cells, not batteries.)
Comments
Horrendously low output, but they keep on delivering it for year after year after year after...
But mostly, the '20 year on a battery' is marketing-speak for 'this thing uses very little power and we don't really know how batteries work or dare to ask the geeks that know since they're going to tease us'...
The coin cell in our computers have probably lasted the longest. They have enough of a spark in them to keep the bios in the computer.
We made our own batteries in science class in the 9th grade. We had a jar, strips of lead, purified water and wires and they had a special battery charger with a fuse. I think a less corrosive battery like a gel battery might last longer but that is my personal untested opinion. You need to have materials that last. For example, Liquid plumber is stored in a bottle but not in a can and it is safe long term to be used in PCV piping but my plumber says its not safe to be used in metal. If it was safe for your pipes then why isn't liquid plumber stored in a can?
My wife recently bought a Ben 10 flashlight at Toys R US and the back of it said something like "do not use rechargeable or alkaline batteries in this flashlight". The funny thing is there are AA batteries that are 1.2 volts and AA batteries at 1.5 volts and I found some AA batteries that are for non high drain devices, they were 97 cents for four and I found them at Wallmart.
C.W.
While we're on this subject, has anyone tried using rechargeable lithium batteries in smoke detectors? I've been weighing the safety of this idea. I don't really know.
It is still running.
-Tor
Here is a battery that last up to a few lifetimes. Its using the electrowetting principle.
http://mphasetech.com/
http://www.all-battery.com/primarylithiumthionylchloridebatteryddsize36v36aher341270-ultrahighcapacitycell.aspx
I may get one just casue it would never die in my TV remote ..
Remember this, it doesn't matter what type of batteries you have, its all in how you maintain, charge and amp draw on these will determined how long these batteries last.
I had over 100 units spread all over Australia when they started failing. Fortunately they were all at the end of stat muxes over leased phone lines for data comms to minicomputers. I did at least have boot code in an eeprom so fortunately was able to re-download the code from a central site as each failed due to a power failure. Ultimately they were recycled and I burnt the code into eeprom as the code had now been stable for a few years and no updates were now anticipated.
So, it doesn't matter what the specs say, reality is the proof.
Now there are other possible failures, apart from product obsolescence. Some capacitors (or batches of capacitors) have been found to have short lives, but usually only after they have been in the field for some time. The newest chips pushing the latest geometries are supposed to suffer from metal migration because they are now so fine. They are supposedly only guaranteed to last 10 years! (source IIRC: Chips broadcast at the UPExx - one before last).
Maybe a supercap that can be recharged without damage may be a possible alternative though you would need to check its life expectancy.