Hey there you fine people!
I have several flashlights now in my budding collection. I have left them all loaded with batteries.
Does leaving batteries in them wear out the spring tension faster than “exercising” them by loading them every once in a while? I haven’t been able to find an answer yet.
If so, I’ll unload all but my EDC.
I have never had one to lose its tension. If you repeatedly work the spring and cause heat build up it can unload the spring.
I have had that happen with automatic knives where I was just try to wear in the blade bushings and loading and unloading repeatedly until I closed the knife for awhile and then the spring had cooled while compressed. Needless to say the spring had lost its spring.
I have a Akoray k-106 that I have had a battery in for at least 10 years and the spring still works fine. Its been modded a couple of times but still the same switch and spring.
Springs die due to cycles, not loading.
Chris
I know compression deformation is a thing but i think there’s a limit to how much tension is lost, i don’t think a spring ends up flat because it has been compressed for a long time.
That said, because i don’t know i leave some lights with the tailcap loose to alleviate tension while leaving them close enough to functional to still be useful.
Heat definitely kills a spring though, as i’ve found out when accidently shorting battery terminals…
The Akoray K-106 was one of the first pretty good flashlights that I bought.
I think I ordered it shortly before finding BLF. 
I still have mine somewhere around here.
Cool. Looks like batteries will stay in the lights.
Good people in here. I’d half expected to be be-littled for being concerned about something like this, but no. Thanks a lot!
Thats not something we do here, we are more less self policed and try our best to be respectable to others.
I see your pretty new here, Welcome to BLF.
This is not “spring” related, but “battery” related: try not to leave alkaline batteries in your batteries for a long period if you are not using them.
Or, if you do, protect the springs due to potential leaks from these cells.
Last week I retrived 4 AA alkalines from different flashlights. 2 of them were starting to leak and starting to damage the springs.
So, for the good of your lights and the reliability of their use when needed, don’t leave alkaline batteries inside :+1:
Yes, good advice. Fortunately I don’t use any alkaline. Thanks though, for sure!
Vinegar on a cotton swab will dissolve the residue and clean the springs and plates from alkaline battery damage.
Also:
Lithium ion batteries have an ideal voltage for long-term storage, in the range of 3.6-3.7 volts.
Lithium ion batteries do have some self-discharge, so I’d recommend checking on unused batteries yearly at a minimum.
While simple flashlights with switches that disconnect power do not do this, other types of flashlights will have a standby drain on the battery. On well-designed lights, it’s less drain than the self-discharge of the battery, so you can just see the preceding point. On others, it’s a very real concern, and those lights should be stored physically locked out (the current path broken, typically by partially unscrewing the head or tail) or without batteries in them.
As has already been mentioned, springs wear out primarily by being cycled (compressed/uncompressed) rather than left in one position. Some caveats: heating and cooling of the springs can cause deformation, and over-compression or over-extension can cause deformation as well. Over-compression is less of an issue, as the majority of springs I’ve encountered can be fully compressed without issue (in the case of conical springs, this sometimes even means pressed flat).
Is vinegar better than bicarbonate of soda? I always use bicarbonate but it doesn’t work that great to be truthful.
Vinegar for the acidic properties to eat the corrosion away. Bicarbonate of soda to neutralize the acid as well as to be used as abrasive sandpaper properties.
2 different things that always best work together since they’re the ultimate ingredient for science show volcano experiments
It will leave them clean and shiny like brand new, no muss no fuss.
Baking soda is a chemical with a pH on the side of “base”, as are alkaline salts.
Vinegar is a chemical with pH of weak “acid”. Mixing an acid and base results in a vigorous reaction as they try to neutralize each other. So that is why baking soda doesn’t work, and vinegar will work to dissolve the alkaline leakage.
Mixing vinegar and baking soda has a vigorous reaction with release of carbon dioxide gas, but it does nothing for household cleaning of anything, although internet folks sometimes think it will act as a cleaner due to the bubbly reaction.
Got to run, cookin’ up a batch of them pharmasweaticals…
If the vinegar doesn’t do it, there is an awesome product called DeOxit that’s worth trying for contact cleaning. I hadn’t heard of it but picked that recommendation up on Eevblog. The stuff is magical but spendy. They make a red colored product for cleaning, and a blue colored one for coating so as to resist corrosion. If you are taking a flashlight out into the sea thats a worthy item to pre-coat springs etc with.
