Long-lasting battery

Piotr-

One way would be 25% Duty Cycle.

My tools that use Lithium batteries have not been available more than a few years. I'm sure they are good, and definitely hold their charge better than NiCd. But I worry about their claiming "PROVEN TO LAST".

I wonder if Tadiran expects that tools will not last as long as batteries?

Fred

At the bottom of the page:

• Tadiran LiSOCL2 Long life lithium batteries feature the lowest annual self-discharge rate of any competitive battery, less than 1% per year, enabling these batteries to operate over 40 years depending on device operating usage. However, this is not an expressed or implied warranty, as each application differs in terms of annual energy consumption and/or operating environment.

It appears that they base the battery life on the self discharge rate. There are many applications that have a very low current drain, and a very low duty cycle. 0.7% self-discharge per year times 40 years =

28% loss, leaving an energy budget of about 23% to run some device for 40 years. (You don't want to discharge the battery to zero. 50% is safe).

"The 40-year battery pack" See "Proof that bobbin-type LiSOCL2 batteries can last 40 years" section.

"Is a 40-year Battery Life a Reality?"

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

In 1981 I worked at a place using D sized Tadiran Lithium Thionyl Chloride primary cells. I think Tadiran had been already making them a few years by then.

I have no reason to doubt their 40 year life claim.

piglet

================

** Boy - have not seen that brand name mentioned for decades.

Back in 1979, I bought a dozen C size Ni-Cd cells made by Tadiran in Israel.

They did not last very long in a model speed boat. Figured they were engineered for 6 day wars ..........

..... Phil

On a sunny day (Sun, 5 Jul 2020 06:48:44 +0100) it happened piglet wrote in :

It all depends, Duracell lasts at least 7 years, bought old radiation meter in 2012 for 5 Euro in army surplus, inserted new D type Duracell (says best before 2017 on it)

Checked last week after discussion about it, obviously forgot to remove the battery. Was still 1.56 V and could light a bulb, thing still works. These are the pen type meters..

As it did not leak it should last 4ever with low current load?

Tadiran is a completely different beast. It is the self-passivating thionyl chloride get-lost-we-will-not-ship-it-anyway toxic-waste-disposal-protocol-required chemistry. Otherwise very nice:

"Capacity retention after 10 years: 96%"

That would make 85% after 40 years, pretty amazing if true.

Thanks for an interesting observation, Jan. Yes, 4ever is the name of the game here. 2uA load current max. This is for backup purposes, so I would prefer a supercapacitor, but even the crazy Evans hermetic ones:

can last only 25 years when energised and have 25uA of leakage current (a very carefully hidden parameter). For 1F and 3.3V initial voltage it takes 85kiloseconds to go down to 1.2V. One day, hardly a backup.

Best regards, Piotr

Isn't their use of "proven" is incorrect? They haven't "proved" anything, just "projected" what will happen based on shorter-term data they already have. If they'd said "projected to last 40 years on current data" there wouldn't be an issue.

--

Jeff

=================

** Lots of good data here:

** See above - they are not really making wild claims.

.... Phil

On a sunny day (Sun, 5 Jul 2020 09:28:05 +0200) it happened Piotr Wyderski wrote in :

OK, 2 uA is lot There are radioactive decay batteries

And

and you can make those yourself, tritium light into photocell? :-)

There are ready-made units from CityLabs:

Unfortunately, the "self-discharge rate" of tritium alone is 50% per 12 years, not counting any ageing effects. Plutonium 238 would be far better, but the sellers are a bit reluctant.

If the LiSOCl2 things are capable of delivering what they promise, betavoltaics makes no sense.

One interesting observation is the lack of long-lasting supercaps. No idea what makes them impossible, though.

Best regards, Piotr

So then maybe it is worth trying. I am considering a D sized unit as well, but nothing smaller than C.

Thank you, all!

Best regards, Piotr

On a sunny day (Sun, 5 Jul 2020 13:22:41 +0200) it happened Piotr Wyderski wrote in :

For 20 uA during 40 years you need a battery capacity of

-> 20E-6 * 24 * 365 * 40 = 7.008 Ah

There are many ways that may be used to occasionally update charge in a supercap or battery: light, thermocouples. Peltier, motion, sound, pressure, RF fields, etc... Is your application free of all those?

el.

I had a model boat which used alkallines and putted around for a while on a set. Then I bought NiCds and the thing flew! Seems the motor was starved for current on alkalines. But instead of running for half an hour they ra n out in 10 minutes of course. Not the battery's fault.

Don't know what happened to that boat. It should be around somewhere, but I haven't seen it in decades.

--

  Rick C. 

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I have plenty of power most of the time; there is no problem with charging current. The problem is that there will be nothing to charge eventually. Even the "high reliability" supercaps are claimed to last for only 25 years, and it is almost impossible to get them. This battery is the best thing I can currently get, and this fact is rather disappointing.

I was thinking about boiling 250ml of water and then use it as a heat reservoir for a TEC, but it is unlikely to stay usefully warm for 2 weeks.

Best regards, Piotr

.

I can't begin to help you because I have no idea what you are trying to do or what your goals are. You've asked about the lifetime of a battery and s een to be saying 25 years is too short. An energy storage method that will operate for longer than 25 years will be exceedingly hard to come by. Hav e you considered something powered by the weather like water powering a tur bine? A sufficiently large reservoir can operate for a very long time with proper maintenance. But then if you can maintain it I'm guessing you coul d provide fresh batteries.

Are you aware that lithium thionyl chloride is a primary cell and not recha rgeable? How much power do you need to store?

--

  Rick C. 

  - Get 1,000 miles of free Supercharging 
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On a sunny day (Sun, 5 Jul 2020 18:03:24 +0200) it happened Piotr Wyderski wrote in :

My nicads still work after 40 years (from the eighties) as SRAM battery backup here:

the yellow thing, was not even new at the time but from an old Philips VCR. High self discharge so needs often charging I have tested an other nicad last year that was also at 0V and after charging it worked normally.

Anyways how sure can you be the world as you know it still is there in 40 years. Was just watching a documentary about the Aztecs in where now is Mexico city:

:-)

When the Spanish came it was all over for them. Now Russia China Europe some S American countries and of course Texas history has this tendency to repeat itself.

Thanks for that. The OP's ref wasn't so useful.

True, but at in section "Proof that bobbin-type LiSOCL? batteries can last 40 years", they have only 26 years of real-time data, with a lot of accelerated testing in support of their 40 year claim.

Many years ago I worked in pharmaceuticals, all of which have a stated shelf-life to meet guaranteed specs (minimum of 90% active content). One product was not allowed a 3-year shelf-life, even though accelerated testing supported it, as real time data was available for only 24 months. At 26 months it suffered catastrophic, unpredictable, instability to below 75% of active content. That's why I have a problem with "proven".

--

Jeff

Could be the difference between test date ( guaranteed ) and field data (proven). Just means that they are used less extremely in the field than they are designed for.

End-user's derating for application playing a part there.

RL

The goal is to have a backup power system capable of supplying 2uA at

1.8-3.6V for 2-4 weeks. Operational after 40 years of being energised. 25 years is the specified lifetime of a Capattery supercapacitor. But it is not relevant, as its specified leakage current is 25uA, which at 1F is good for a day. Two independent reasons not to go that way.

I wouldn't dare to bother you with simple questions. :-)

And you are correct, I need a storage element, not necessarily an energy source that is able to provide that amount of current continually for 40 years. The battery can do it according to the marketing data, but it is not strictly necessary.

No mechanical system available to me would last that long. It just needs to have no moving parts. This is for a maintenance-free system.

Yes, but if it can survive that long, it does not have to be. This method is not solving the real problem I have, thay is, to buy a super-long life supercap. But if it is the only option left on the table not counting betavoltaics, let it be that way.

Best regards, Piotr