Li-Ion rechargeable batteries shelf life: Tek says 3 years only, I do not agree - Page 1
Forum section: electronics / projects

author: mcinque
author_rank: Unknown
timestamp: July 08, 2018, 03:51:41 pm
content: The Tektronix's"Lithium-Ion Battery Maintenance Guidelines"says "The typical estimated life of a Lithium-Ion battery is about two to three years or 300 to 500 charge cycles,whichever occurs first."While after 300~500 full charge cycles there is an effective substantial degradation of battery thatanyone can see(for example after years of use and everyday charging a mobile phone's battery of mine it's really bad and can't keep the unit powered on without being costantly powered by the wall charger), I have old lithium rechargeable batteries that works quite fine after almost 15 years (Plantronics headset, Siemens/Nokia GSM phones). They don't have the same performance of course, but they are far from be dead like Tektronix estimates.In the world we have tons of rechargeable lithium battery powered mobile phones, mobile consoles, laptops, printers, mp3 players etc. sitting on the shelfs waiting to be purchased by a customer.Their battery manufacturing date can be also 3 or 4 years before (or even more) the device's manufacturing date or purchase date. The consumer should have a depleted or low performance battery. Instead, they works fine.What do you think or what's your experience about shelf life of rechargeable lithium batteries? In your experience it is true what Tektronix says?

author: leonababy
author_rank: Regular Contributor
timestamp: July 08, 2018, 04:02:42 pm
content: A couple of observations from only the guide, and not experience or knowledge: the guide does not address shelf life of a product prior to use. My inference is that 2-3 years or 300-500 cycles whichever comes first is for a battery that is being used. Also, it doesn't say consider the battery "dead" if one of these conditions is satisfied - my inference is they consider the battery in need of replacement at these points to give an expected level of performance.http://www.newark.com/pdfs/techarticles/tektronix/LIBMG.pdf

author: tsman
author_rank: Frequent Contributor
timestamp: July 08, 2018, 04:22:31 pm
content: Batteries do start to slowly degrade from the moment they're manufactured so they're not lying there. How you're storing it and how much you're discharging it will also greatly affect the life of your battery. For maximum life, you're meant to store them at a specific partial charge level and also keep them within a temperature range. Storing it completely flat, 100% charged or in a high temperature location will greatly accelerate the aging.The usual estimates for life are based on some % decrease in total capacity and not down to 0% where the battery is completely dead. The PDF mentions replacing the battery if "battery run time drops below about 80% of the original run time" so presumably 2-3 years or 300-500 charge cycles is roughly where Tek expects that to happen.Quote from: mcinque on July 08, 2018, 03:51:41 pmIf I bought a new battery pack and it had been sitting on the shelf for 3-4 years then I'd take it back and ask for a new one that had been manufactured more recently.

author: mcinque
author_rank: Unknown
timestamp: July 08, 2018, 05:12:15 pm
content: QuoteYes, storing charge is important, as temperature.QuoteOk so for "end life" they mean less than 80% run time performance. It's a lot better.Quote from: tsman on July 08, 2018, 04:22:31 pmMe too but, not many consumer products or batteries have manufacturing date (easily) visible, right?

author: KL27x
author_rank: Super Contributor
timestamp: July 08, 2018, 09:55:40 pm
content: QuoteThe "3 year shelf life" is something that has been bounced around by manufacturers of electronics devices and lithium batteries since the beginning of time.My portable scope is powered from 8 li ion 18650 cells, four of which were taken out of a Dell Pentium laptop battery from the late 1990's. Granted, I have used this scope once in the last 4 years. But prior to that, the same set of batteries powered an electric drill for several years, and they got plenty of use. I assume the batteries are still good (the drill runout was not).Since the Great Depression, the world has learned that throwing things away and buying new ones is good for the economy, so take w/e they say with a grain of salt. The electronics and battery industries have been built on ~3 year cycle for several decades, now. They don't want that to change.

author: leonababy
author_rank: Regular Contributor
timestamp: July 08, 2018, 10:16:21 pm
content: Quote from: KL27x on July 08, 2018, 09:55:40 pm