Any rechargeable coin cell batteries?

[ruriimasu]

Hi,
I just got myself a couple of coin cell keychain lights and the drain power quite fast. i would change fresh cells whenever the light dimmed. i know the remaining power in the used cells will still last me quite a while but i want it at its brightest. its a shame to have to discard the partially used cells. so i would like to know whether there is any rechargeable coin cells, specifically for AG3? thanks.

 

[VidPro]

yes there are rechargable coin cells, see
li-ion
http://www.batteryspace.com/index.asp?PageAction=VIEWCATS&Category=912

ni-mhy
http://www.batteryspace.com/index.asp?PageAction=VIEWCATS&Category=706

a AG3 though is concidered a "button" sized cell vrses coin, and you would probably want to get them in a ni-mhy or ni-cd

ALL of these things have DISMAL capacity, i find that unless the device you place them in has a charging port so you dont have to remove them, its a waste of time. they usually have 1/3-1/4th the total capacity in numbers for the tiny rechargables.

getting silveroxide , instead of alkaline , will have a longer runtime, but are very limited in pulse current output.
getting a Zinc air (type) , instead of an alkaline can get you 2-4times as much total runtime, with the caveat of they will die on thier own if not Resealed (air in) or used up in a few weeks or so.

best bet for most of the things that use the AG3 is a bulk rate on BRAND quality alaklines, or a big pack of cheap china ones , depending on how realiable it needs to be, and how often you want to change.

looking into the other chemistries (the name will change but the basic voltage and size will be the same) works out good if you and your device fit the profile for the type of output they do. you just find comparitive SIZED items in the other chemistries, and dont expect them to actually be called AG3 (the alkaline button cell name)
like a set of Zinc-air, can run a marker light for >3 times as long non-stop.

 

[ruriimasu]

vidpro,
thanks for your reply. but its too technical for me!
so let's say if i get myself a rechargeable button cell the size of AG3, is the rechargeable cell's capacity only 1/3/ or 1/4 the power of that the normal AG3 cell? is AG3 an alkaline or not, and how long can it last if left unused (as in stacked together inside a light. i heard it loses power when they are stacked together)?

 

[VidPro]

stacked batteries rechargable or not , dont have an issue with discharging any noticable ammount because they are stacked. if there is a discharging issue from being in the device, it would usually be the device itself not completly disconnecting. OR if the device is electronic curcuit switching style , like these multimode driver things, they can have a very tiny draw of power like 10-60u pico type amps VERY very small ammount of standby current, but given enough TIME, that will still drain the batteries. and there isnt much battery to begin with.

i have a light that draws a very tiny draw of current when off , because of electronic switching, but after doing the math, i calculated it would completly drain my battery (even with that small a drain and big batteries) in one or 2 months.

also i should note that moisture , even from sweat, i have had pocket key lights end up turning on (slightly) from moisture connections, and i was not near water, rain or anything, it was just mosture from my body, it doesnt take much moisture to make a slight (battery draining) connection when the difference between connecting (on small stuff) and not connecting is less than a milimeter of space.

yes you would only get 1/3-1/4 the power out of most of the tiny rechargable cells, but on the other hand, if it is a good ni-cd or ni-mhy and the device uses a lot of power when on, it still might be usefull.
like say a high powered laser with tiny batteries (to dang small for the device) might work better for the short uses , vrses an alkaline which would drop in voltage faster.

does the device use 3 of the ag3 button cells?
BECAUSE, if that was the configuration, one possible "Upgrade" for it, would be a SINGLE li-ion cell of small size, by using a single cell, there would be much less Metal (wasted space) , and much more electrolyte and plates (power).
they have smaller li-ion cells which have no protection, and would require knowlege to use, and might be a bit HIGH in voltage, but it would be a possilble way to change the present situation, in a way that its not worse than it was.

changing to 3 tiny button ni-cds or ni-mhy would probably not be satisfactory.

stack it up and measure the exact size, then measure the total voltage of the stack, and mabey a 10200 size li-ion would work? you could add in one tiny glass diode to drop the voltage and (like i said) it would be a bit of a mod, but it could be the answer instead of another dismal attempt.

 

[VidPro]

let me put this in English for you

these things that use that battery are a pain in the butt

the china batts that come with them are total trash, they have very little power, and a good FRESH new brand name cells $$$ will work a lot better.

avoid radioshack for these , IF they have low turnover, aged packaging, and the same cheap china battery to begon with, check out some good maxells that are not clones (for example). maxell has holographic packaging now that attempts to insure your getting the real brand name product.

go to your local drug store, and check out the size of a zinc-air , buy a pack and see if they fit and work, its a zinc battery and IF it fits and gives you the pulse power you need, it might be a fair solution.

Totally mod it out of that battery, because while small they can never provide the power you desire.

and the #1 cure for this problem is get a keylight that uses a real battery like an AAA or an AA, they make some very nice AAA sized lights that even have levels, that will replace the BATTERY with a real one.

use lithium coin cell keylight, like the photon and its clones, they have more juice in the primary of that chemistry, and the size is bigger.

 

[ruriimasu]

hi vidpro,
thanks, i understand both of your posts. they are very informational. i was away for 3 days and did not have internet access so the slow reply.
yes, it uses 3 x AG3 button cells. is there a replacement battery for it out there? i used to buy some really small batteries from a guy here who sells AW batteries. can't remember the nick now, maybe he might have such small batteries for the light.
the light i got is actually a Sterops SKC-9Q. i like its workmanship, very nicely designed. it's a very cheap china light but i'm captured by its aesthtic beauty

 

[Phlack]

I can certainly understand the reasoning for this.

I've amassed a bunch of those cube-world devices, and they mostly take CR2032 batteries. Why they just couldn't take a AAA I don't know...that would have been much easier
(btw, the bigger ones...BLock Bash and the tropical one (forget the name) do take real batteries...three AAA's. The new "mod" ones take AAAs (I believe) in the mod case but still the CR2032 in the normal one).

I wound up buying a bulk of CR2032's off of ebay pretty cheaply. Still have them, as I grew bored of the cube world stuff.

-Mike