Non-flashlight battery question.

[Stregone]

Sorry if this is a little offtopic, but I don't know anywhere else with the kind of battery knowledge you guys possess.

I just dusted off my old sega saturn to get some retro gaming in. I booted it up and it asked me for the date and time. The backup battery is dead and I lost all my saves A quick google tells me that it uses a CR2032 lithium button cell, and that these have about 200mah capacity which will keep saves for up to 5 years.

I was thinking of instead of replacing the button cell, wiring up a larger capacity 3V lithium cell like a CR123A, or CR2. Based upon the 5 year for the button cell statement, these will give me about 30 and 15 years backup respectivly.

I was thinking of cutting out a peice of wood the size of the button cell, with some copper plate or something glued to each size and solder some wires to it. And the wires to the battery(does anyone make battery holders for those size cells?). The battery is easily accessable from a removable compartment cover and there's plenty of room in there for a bigger battery.

Has anyone tried this sort of thing before? Any glaring flaws that I don't see? Thanks

 

[doc_felixander]

DOn't see why it shouldn't work.

Personally, I wouldn't even build that adaptor thingy and solder directly to the contacts.
If you are good enough at soldering, you can solder the leads to the battery contacts (I know, people here will start screaming about this.)

Just keep in mind that the small pad of button cells is negative.

 

[VidPro]

only flaw i see is the life of a lithium is only going to be 10-15 years. heck long enough.

i stuffed 2 AAs on an old clock/calender that used button cells, and it has faithfully beeped at noon for almost 8 years now. the button cells never lasted long.

 

[DM51]

Do NOT try to solder direct to the battery terminals unless you have a particular desire to have it explode in your face while you are doing it.

Your idea of making a holder is OK otherwise - you just need something to hold the wires firmly to the battery terminals. Magnets soldered to wires are one idea, used quite a lot for charging etc by people here.

A CR2 or CR123A will not give you a proportionately longer run-time. Lithium cells have a 10 year life and whichever one you choose will die some time after that, whether or not all of its capacity has been used up. You may get lucky with a good one that lasts longer than 10 years, but don't bank on it. 30 years is far too optimistic.

 

[Stregone]

Yeah I figure the cells won't last that long, but longer than 5 years. I completely forgot that 2x alkaline cells = 3V. Do the lithium cells have a longer shelf life than alkaline?

 

[oldvultureface]

Do the lithium cells have a longer shelf life than alkaline?

Yes.

I'm looking at two recently purchased batteries. The lithium's "use before" date is 2021 and the alkaline's is 2013.

 

[VidPro]

ya know, all the times people have asked about the SLOW discharge rate CMOS backup lithiums, this might be the best thing possible to use them for.
they have soldering tabs or wires already welded on.

they never would work for flashlights because they are not desinged for fast discharge, but they ARE designed for this kinda thing.

 

[Stregone]

ya know, all the times people have asked about the SLOW discharge rate CMOS backup lithiums, this might be the best thing possible to use them for.
they have soldering tabs or wires already welded on.

they never would work for flashlights because they are not desinged for fast discharge, but they ARE designed for this kinda thing.

Where can you get them?

 

[VidPro]

here is one style
http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=802

another here
http://cgi.ebay.com/Lot-10-3-6VDC-L...goryZ164QQrdZ1QQssPageNameZWD1VQQcmdZViewItem

aa sized here
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=7577155031&fromMakeTrack=true

Note: a lot of times the reason these are very cheap is they are older, still have 5-8 years in them, but are cheap because they are not going to install them in medical and military equiptment.
i only post the links to provide the idea.

 

[Stregone]

i think I'm going to go with a CR123A, because batteryspace sells a holder for it. Is there a free shipping code I can use? Cause I don't wanna spend 7 bucks on shipping for 1 cell and 1 battery holder (less than 2 bucks).