Replacing SNES cart batteries

FatCobra · Post by **FatCobra** » Wed Jun 08, 2005 3:51 pm

Well, thanks to Accutron, I am back on the path of experiencing SNES goodness. I've ordered an Earthbound cart off of eBay, and a thought crossed my mind:

This game is ten years old....will the battery be dead? So because I love Earthbound so much, I want to give the cart a new battery. But how do I take apart an SNES cart so I can give it a new battery? What type of battery does it take? I probably need one of those special screwdrivers too. Where can I get one of those?

EDIT: Just bought the screwdriver bit. That takes care of one problem.

Post by **BulletMagnet** » Wed Jun 08, 2005 3:59 pm

My brother actually just ordered a used copy of Yoshi's Island recently, and the battery still works on that. Earthbound, IIRC, wasn't released too much earlier than that, so the battery might still work on that too. As for how to install a new one, I've never done it myself.

FatCobra · Post by **FatCobra** » Wed Jun 08, 2005 4:02 pm

Well, I guess SNES carts don't gobble up batteries as fast as the Sega Saturn does.

Still, I do want to give my cartridge a fresh start.

Post by **BulletMagnet** » Wed Jun 08, 2005 4:05 pm

FatCobra wrote:Well, I guess SNES carts don't gobble up batteries as fast as the Sega Saturn does.

If they did, I'd have lost my Zelda save back in 1995 or so, heh.

Accutron · Post by **Accutron** » Wed Jun 08, 2005 4:20 pm

I've never changed the battery in one, but I just popped open my copy of Donkey Kong Country, and it just has a normal old CR2032 in it..looks like it's been lightly spotwelded to the battery terminal. You would probably have to carefully break the spotwelds by wedging a small flathead screwdriver or knife edge between the terminal and the battery. You can get a new CR2032 pretty much anywhere that sells watch batteries.

Zach Keene · Post by **Zach Keene** » Wed Jun 08, 2005 4:56 pm

Moved to Hardware.

marcus12024 · Post by **marcus12024** » Wed Jun 08, 2005 5:52 pm

Just for fun I thought I'd mention that my Legend of Zelda gold cart for NES still has my save files, from 1988!

A curiosity - cartridge games were always using batteries for storing save data, does anyone know if newer carts (like GBA/DS) are using tiny bits of flash memory instead? Correct me if I'm wrong, but flash memory retains its value without any sort of battery backup. This would mean much longer save file retention. Also, they could slap in about a meg (for likely a few pennies nowadays) for save data, so that more games could be saved.

Rastan78 · Post by **Rastan78** » Wed Jun 08, 2005 7:22 pm

I've done this a few times before. You've got to be real careful when you solder directly onto a battery because if you heat it up too much, acid will start leaking out and the battery is of course useless. This is hard to do if you're soldering onto that big metal tab that was attached to the old battery.

One solution I found was to solder fairly long wire leads onto the battery, which are pretty easy to get a good join without heating too much. The other end of the leads obviously goes to the correct spots on the cartridge PCB. You can use tape, hot glue or whatever to secure the new battery to the inside of the plastic casing of the cart and then fit it all back together.

FatCobra · Post by **FatCobra** » Thu Jun 09, 2005 3:28 am

So wait, the batteries in SNES carts are soldered in there? Damn batteries better last a lifetime then.

EDIT: I don't want to risk damaging my Earthbound cart so I'm going to buy a copy of Super Mario World to pratice the art of SNES battery changing.

Accutron · Post by **Accutron** » Thu Jun 09, 2005 11:12 am

FatCobra wrote:I don't want to risk damaging my Earthbound cart so I'm going to buy a copy of Super Mario World to pratice the art of SNES battery changing.

That's probably a good idea. Rather than soldering directly to the battery though, I would suggest getting a CR2032 battery clip of some sort, and soldering it instead. It will make future battery changes much easier, and eliminate the change of frying your battery with a soldering iron.

FatCobra · Post by **FatCobra** » Thu Jun 09, 2005 2:41 pm

I don't know how to solder.....

Accutron · Post by **Accutron** » Thu Jun 09, 2005 2:54 pm

Soldering isn't hard. Google up some instructions on how to solder properly, get a low wattage iron and some rosin core solder (~$10). You might also be able to come up with a solderless solution, by bending the top terminal and some creative tape use, but I wouldn't recommend it.

FatCobra · Post by **FatCobra** » Thu Jun 09, 2005 3:11 pm

Well, soldering may not be hard, but I've never done it before....

Can somebody show me what the guts of a SNES cart look like? More specficially, I wanted to know how the battery is set up.

I am going to pratice on Super Mario World carts since they are a dime a dozen and the game will work fine without the battery (It's a Mario game for crying out loud!)

I gotta wait for the screwdriver to come in the mail however...

iatneH · Post by **iatneH** » Thu Jun 09, 2005 3:23 pm

Yup, soldering is easy and it's definitely a useful skill to have.

My parents sent me to an electronics for fun summer course when I was in sixth grade, and everything I know now about electonics, I learned from there.

I've done a few console and controller mods and just yesterday I just finished building my first supergun (didn't use a pre-wired JAMMA harness either, just a bare 28x2 edge connector), so a little bit of skill goes a long way ;)

FatCobra · Post by **FatCobra** » Thu Jun 09, 2005 3:27 pm

Hmmmm...well maybe learning to solder so I can mod and fix videogaming stuff would finally get my parents off my back about videogames being a useless hobby.

iatneH · Post by **iatneH** » Thu Jun 09, 2005 3:35 pm

Hehe, just be careful because once you learn to solder, it opens up a whole bunch of new ways for you to spend a lot of money :)

Accutron · Post by **Accutron** » Thu Jun 09, 2005 3:37 pm

Super Mario World...

PaCrappa · Post by **PaCrappa** » Thu Jun 09, 2005 8:34 pm

I still haven't needed to change one but I was under the impression that 2032 batteries could be purchased with those solder tabs built in. Anyone know if that is correct? If so, does anyone know where to find the things?

Pa

Accutron · Post by **Accutron** » Fri Jun 10, 2005 3:02 am

Yeah, you can get CR2032's with tabs pre-attached. If you're in there desoldering things anyway though, it would seem to make more sense to install a clip so you can change the battery more easily in the future.

The Bullet Dodger · Post by **The Bullet Dodger** » Fri Jun 10, 2005 10:02 pm

Just out of curiosity, does anybody know how long the batteries in the SNES games are supposed to last?

Accutron · Post by **Accutron** » Fri Jun 10, 2005 10:19 pm

I've never seen a device spec rate a CR2032 used for static RAM backup for longer than 5 years, but 10-15 years (maybe even 20) may be more realistic for a SNES cart, based on anecdotal evidence.

FatCobra · Post by **FatCobra** » Fri Jun 10, 2005 11:20 pm

It probably doesn't take much juice to power a small RAM chip like on the SNES carts, so maybe they last a real long time.

The better the RAM chip, the faster it will guzzle the battery. I still think the Saturn's interal memory was a brilliant idea on Sega's behalf.

Is anyone sick of memory cards yet?

Post by **BulletMagnet** » Sat Jun 11, 2005 12:36 am

FatCobra wrote:I still think the Saturn's interal memory was a brilliant idea on Sega's behalf.

Perhaps for awhile, but once you started amassing more games you'd have to buy a memory card anyway. Especially if you were playing an RPG or something...but even on the shmup front there are some real memory hogs on the Saturn...I think Garegga takes up about 80 blocks, and Souky is also close to 100 out of the 300 it gives you.

Accutron · Post by **Accutron** » Sat Jun 11, 2005 10:59 am

FatCobra wrote:It probably doesn't take much juice to power a small RAM chip like on the SNES carts, so maybe they last a real long time.

The better the RAM chip, the faster it will guzzle the battery. I still think the Saturn's interal memory was a brilliant idea on Sega's behalf.

Is anyone sick of memory cards yet?

Different kinds of volatile RAM have different power requirements to maintain their contents. Dynamic RAM requires a constant power refresh to hold its data, while static RAM (like in SNES carts) doesn't. Static RAM has faster access time than dynamic RAM as well, making it all-around superior performance-wise. The drawback is that static RAM uses four transistors per bit, while dynamic RAM requires only one transistor per bit, and is consequently much cheaper to manufacture.

I greatly prefer modern flash RAM memory cards. Portable, no batteries. The thing is, they need to start bundling them with new systems.

matt · Post by **matt** » Sat Jun 11, 2005 11:53 am

I think Nintendo offers a battery change service, if you don't want to do it yourself - $5 a cart IIRC.

Save batteries do last a very long time. I'd say that about 75% of the Zelda carts that have passed through my hands have still worked. Seeing how most are 20 years old by now, those are pretty good odds. You can probably expect at least 15-20 years out of your games, so you should have the chance to play through Earthbound several times before it kicks the bucket.

Considering that you have to change the batteries less than once a decade, the whole battery clip thing seems like a waste of time. Never mind that there's a chance of the contacts getting dirty/bent and killing your saves prematurely.

Batteries with tabs attached are available at most electronic supply shops. Highly recommended if you plan on doing several carts, since they save a lot of time and burnt fingers. Soldering directly to batteries isn't as difficult are people make it out to be, but you do have to be careful in order to make it work.

I've had a couple of CR2032s pop due to carelessness, and the results aren't as spectacular as you'd think. Typically, the casing just splits slightly - no massive explosion of acid or anything. Still, if the stuff gets in your eyes it can't be good.

FatCobra · Post by **FatCobra** » Sat Jun 11, 2005 4:37 pm

BulletMagnet wrote:
FatCobra wrote:I still think the Saturn's interal memory was a brilliant idea on Sega's behalf.
Perhaps for awhile, but once you started amassing more games you'd have to buy a memory card anyway. Especially if you were playing an RPG or something...but even on the shmup front there are some real memory hogs on the Saturn...I think Garegga takes up about 80 blocks, and Souky is also close to 100 out of the 300 it gives you.

My Saturn came bundled with a cartride memory, so I'm good to go.

Accutron · Post by **Accutron** » Sat Jun 11, 2005 5:05 pm

matt wrote:Considering that you have to change the batteries less than once a decade, the whole battery clip thing seems like a waste of time. Never mind that there's a chance of the contacts getting dirty/bent and killing your saves prematurely.

Clip or pre-tabbed battery, it's still two solder joints. I can't imagine what you'd have to do to a SNES cart to dislodge its battery from a good quality clip, but I doubt the rest of the cart would survive it.