Charging a stupidly old battery induces thermal and chemical stresses which can cause fragile internal cells in the battery to rupture, of course they can also do this on their own eventually but yes trying to charge likely helped the rupture to progress.

Personally if I see anything that even resembles a Varta barrel battery it gets its ass nixed real fast, its not even worth the risk to keep it on the board.

They can and will eventually leak on their own as the seals in the battery fail and the electrolyte destroys them and then the board/traces/ICs/Sockets and pretty much anything else it can reach. (Yes even the case ...some Toshiba laptops used Varta batteries that leaked and ate the chassis)

So apparently these don't leak if no charge is applied, based on my sample size of one.

I have a few boards with pristine looking batteries. That condition never changed after few years of laying around in my possession. So yeah, no charge = no destructive chemical reaction.

The Serpent Rider wrote on 2023-02-17, 13:47:

So apparently these don't leak if no charge is applied, based on my sample size of one.

I have a few boards with pristine looking batteries. That condition never changed after few years of laying around in my possession. So yeah, no charge = no destructive chemical reaction.

But we know that this isnt exactly true ...I mean all the 286/386/486 boards with Varta batteries that haven't been used/charged in decades all with massive corrosion from leaking Varta batteries.

Unless you are being sarcastic, given up trying to tell with your posts 🤣.

Only batteries I don't see leaking are the CR lithium cells . .which don't get charged ..I guess if you consider that then your post is correct.

Roundhouse kick a NiCd into the concrete. Slam dunk a NiCd into the trashcan. Launch NiCds into the sun.

TrashPanda wrote on 2023-02-17, 13:50:

But we know that this isnt exactly true ...I mean all the 286/386/486 boards with Varta batteries that haven't been used/charged […]
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The Serpent Rider wrote on 2023-02-17, 13:47:

So apparently these don't leak if no charge is applied, based on my sample size of one.

I have a few boards with pristine looking batteries. That condition never changed after few years of laying around in my possession. So yeah, no charge = no destructive chemical reaction.

But we know that this isnt exactly true ...I mean all the 286/386/486 boards with Varta batteries that haven't been used/charged in decades all with massive corrosion from leaking Varta batteries.

Unless you are being sarcastic, given up trying to tell with your posts 🤣.

Only batteries I don't see leaking are the CR lithium cells . .which don't get charged ..I guess if you consider that then your post is correct.

Depends on the definition of "no chemical reaction" and "empty" 😀

(1: at 0 V the electrochemical reaction has fully completed, but probably not all the products - or the reagents, as they're probably not precisely matched by mass - are inert with regards to the shell;
2: the usual "0% depends on the application but is more than 0 V")

FWIW I've never seen a nickel battery leak in a computer (in person, that is - plenty of photos from here or "uh I can't be bothered to find a power cable to try this" sellers!), but more than once in totaled furnace mechanical timers, the difference being that in the latter it never really spent tens of months empty, so while there may still be a correlation with charge level it's not most of the story!
Did have a leaking NiMH and CR2032 though 😀

Nowadays, gray market chinesium batteries (including zinc-carbon, the original cheapo leak fests) may outlast, on this point, major brands' heavy-metal-free alkalines - not the first time pandering to illegal dumpers has noticeably worsened product quality...

Ryccardo wrote on 2023-02-17, 19:29:

Depends on the definition of "no chemical reaction" and "empty" :) […]
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TrashPanda wrote on 2023-02-17, 13:50:

But we know that this isnt exactly true ...I mean all the 286/386/486 boards with Varta batteries that haven't been used/charged […]
Show full quote

The Serpent Rider wrote on 2023-02-17, 13:47:

I have a few boards with pristine looking batteries. That condition never changed after few years of laying around in my possession. So yeah, no charge = no destructive chemical reaction.

But we know that this isnt exactly true ...I mean all the 286/386/486 boards with Varta batteries that haven't been used/charged in decades all with massive corrosion from leaking Varta batteries.

Unless you are being sarcastic, given up trying to tell with your posts 🤣.

Only batteries I don't see leaking are the CR lithium cells . .which don't get charged ..I guess if you consider that then your post is correct.

Depends on the definition of "no chemical reaction" and "empty" 😀

(1: at 0 V the electrochemical reaction has fully completed, but probably not all the products - or the reagents, as they're probably not precisely matched by mass - are inert with regards to the shell;
2: the usual "0% depends on the application but is more than 0 V")

FWIW I've never seen a nickel battery leak in a computer (in person, that is - plenty of photos from here or "uh I can't be bothered to find a power cable to try this" sellers!), but more than once in totaled furnace mechanical timers, the difference being that in the latter it never really spent tens of months empty, so while there may still be a correlation with charge level it's not most of the story!
Did have a leaking NiMH and CR2032 though 😀

Nowadays, gray market chinesium batteries (including zinc-carbon, the original cheapo leak fests) may outlast, on this point, major brands' heavy-metal-free alkalines - not the first time pandering to illegal dumpers has noticeably worsened product quality...

Varta barrel batteries are rather notorious for leaking, IIRC its more to do with the electrolyte rather than the charge the battery contains. This doesn't mean all of them leak as some were built far better than others using less cheap materials but the vast majority I have seen made a mess of the vintage boards they were attached to.

Simply put the electrolyte may eventually destroy the seals on the battery and make a royal mess of everything the electrolyte can get to, Ive seen it travel quite a distance from the battery.

The Serpent Rider wrote on 2023-02-17, 13:47:

So apparently these don't leak if no charge is applied, based on my sample size of one.

I have a few boards with pristine looking batteries. That condition never changed after few years of laying around in my possession. So yeah, no charge = no destructive chemical reaction.

Me too ! I have one that still looks like new and works (holds a charge) from 1994 <I never replaced it>. I do keep an eye on it though it being one of 70+ in my collection and only a 386SX-40 am not too worried ;p