How long an AA alkaline cell can live - Page 1
Forum section: electronics / general

author: Axk
author_rank: Regular Contributor
timestamp: December 22, 2018, 12:52:32 am
content: Opened my old AA powered calculator.The cell measures 1.5 volts.Wonder if it's best before or manufacture date. If it's best before then it's like 15 years old and still fine. Surprised.

author: Rerouter
author_rank: Super Contributor
timestamp: December 22, 2018, 12:56:04 am
content: The best before date is most of the time marketing fluff to get you to replace stuff early,As for how long a battery lasts, well that comes down to the quality of construction, funnily enough cheapo chinese batteries tend to fair better here than Duracell or energizer as they run so close to the material limits that leaks are quite common after only a few years.I've opened TV remotes with the original batteries after 7+ years with full charge, The capacity does very slowly decrease due to side reaction inside the battery, but the state of charge remains mostly the same during this degradation.

author: tooki
author_rank: Super Contributor
timestamp: December 22, 2018, 01:08:03 am
content: Unless the word “alkaline” is written on the cell, “heavy duty” means it’s almost certainly a carbon-zinc cell with zinc chloride electrolyte, and not alkaline at all. Is it as heavy as a typical alkaline cell? Usually the carbon-zinc ones are appreciably lighter.

author: james_s
author_rank: Super Contributor
timestamp: December 22, 2018, 06:47:01 am
content: Funny thing is it used to be carbon zinc cells were notorious for leaking and one of several advantages of alkaline batteries is that they didn't usually leak. In more recent years I've had so many alkaline batteries leak that I've quit buying them, it's not unusual for them to leak before the best by date, while still in the package. In a wall clock and a couple remotes I use carbon zinc, everything else gets LSD NiMH.

author: IanB
author_rank: Super Contributor
timestamp: December 22, 2018, 07:04:47 am
content: As noted by others that is not an alkaline cell, that is a zinc chloride cell.I have had zinc chloride cells remain in good working order for well over a decade without leaking and still able to provide good power. So I am not surprised by your observation.

author: IanB
author_rank: Super Contributor
timestamp: December 22, 2018, 07:08:45 am
content: Quote from: james_s on December 22, 2018, 06:47:01 amAlkaline cells leak mainly because a chemical reaction inside them produces gas which increases the internal pressure and forces the electrolyte out through the seals.Zinc chloride cells do not produce gas in storage, so there is no expulsion of electrolyte. Zinc chloride cells leak mainly when the electrolyte corrodes through the zinc casing and spills out through the openings produced. Modern zinc chloride cells are sealed inside a steel outer shell which is impervious to the electrolyte, so even if the zinc corrodes the electrolyte can't get out. Therefore modern zinc chloride cells are somewhat safe and are not very prone to leaking.

author: james_s
author_rank: Super Contributor
timestamp: December 22, 2018, 06:41:31 pm
content: Interesting, I didn't realize they had an outer casing. Zinc cells are not very popular these days due to the low energy density but for things like quartz clocks and TV remotes they're still a viable choice. Alkaline cells in those applications often leak well before they are depleted while the zinc cells will still last years.

author: glarsson
author_rank: Frequent Contributor
timestamp: December 22, 2018, 07:00:52 pm
content: Checked the batteries in a remote control. Two Toshiba AAA super heavy duty with 1.52 volts each. No leakage. They have been in this remote for 23 years.

author: Axk
author_rank: Regular Contributor
timestamp: December 22, 2018, 11:52:16 pm
content: tooki, you must be right it is not an alkaline cell. It weighs 15 g compared to a 23 g new GP alkaline.