Cart battery

[Richard H.]

Does anyone know where to get hold of the tagged coin batteries found in some GBA and VB carts ?. I need the very thin one's with the spot welded surface mount tags.

 

 

 

Thanks

 

 

 

Just found a pic

Edited November 29, 2009 by Richard H.

[shadow460]

I usually have the tabs welded on when I buy the battery itself. Batteries Plus might have locations in, or ship to, the UK.

 

www.batteriesplus.com

[BigO]

Using the search term "solder tab" might help you locate what you're looking for on the 'net.

I'd try searching on the 4 words: solder tab coin cell

Edited November 29, 2009 by BigO

[Stephen Moss]

Have you considered removing the clips off a deal battery (or bying clips) and soldering them to the PCB so that you can just slip a standard coin cell between them, it might be easier than trying to find batteries with the tags on them.

[shadow460]

There isn't much room in those carts. Unless those clips are really small, they won't fit.

[Richard H.]

There's no room for a battery holder in there, they just don't make them thin enough. I could use old tags, but I would have to attempt soldering them on, which is a bit risky.

 

I have found some tagged coin cells for about £2 each, which is expensive I think.

 

There was a guy selling them on EBay a while back, cheap too.

 

 

The original idea was to get them from GameBoy carts (with SRAM) as I'm harvesting the tiny battery superviser chips. But I don't know how much juice will be left in the coin cells after 10+ years.

Edited December 2, 2009 by Richard H.

[Bruce Tomlin]

There's no room for a battery holder in there, they just don't make them thin enough. I could use old tags, but I would have to attempt soldering them on, which is a bit risky.

I think there are bent-metal-only battery holders that you can slide a battery into. If anyone finds a source for these that fit CR2032 cells, it would be a good thing. But there's no way you're going to get the PC motherboard battery holders to fit in a cartridge when mounted on the board.

[Richard H.]

I think there are bent-metal-only battery holders that you can slide a battery into

Found some

 

I had to make a new library for it in Eagle. The - of the battery is actually a pad on the PCB.

 

I'm sure the VB cart case will go on. I'll know for certain when the PCB's get here.

 

 

I'll have to work out how long a CR1225 will last powering a 62256 SRAM. It should be in years I would think.

[channelmaniac]

I'll have to work out how long a CR1225 will last powering a 62256 SRAM. It should be in years I would think.

 

It all depends on which version of the chip... There are standard power then there are low power standby versions. Find the lowest power standby version and you'll maximize your battery life.

[Richard H.]

It all depends on which version of the chip... There are standard power then there are low power standby versions. Find the lowest power standby version and you'll maximize your battery life.

Thanks. I'll look out for those versions.

[Richard H.]

OK, I got hold of some MS6264L SRAM. They will hold data down to 2V.

 

Now, something weird is happening. I'm using the SRAM and 3V CR1225 coin cell with a ICL7673 (automatic battery back-up switch). But as soon as I connected the battery the voltage dropped a whole volt.

 

It's still within data retention range at 2.1V, but only just.

 

I just measured a very old GameBoy cart battery (which uses a custom Nintendo chip for switching) and it's still at 3.1V

 

Can someone confirm that the ICL7673 is appropriate for this, or is there a better way of doing it ?

 

 

 

Thanks

[tz101]

Buy CR-2032 ni-cad batteries at the dollar store for cheap, then use a Dremel to cut the old battery tabs loose. Finally, solder small sections of wire between the new battery and the contact points on the game's PCB, watching for correct polarity. Presto, the game should work like new.

[gdement]

OK, I got hold of some MS6264L SRAM. They will hold data down to 2V.

 

Now, something weird is happening. I'm using the SRAM and 3V CR1225 coin cell with a ICL7673 (automatic battery back-up switch). But as soon as I connected the battery the voltage dropped a whole volt.

 

It's still within data retention range at 2.1V, but only just.

 

I just measured a very old GameBoy cart battery (which uses a custom Nintendo chip for switching) and it's still at 3.1V

 

Can someone confirm that the ICL7673 is appropriate for this, or is there a better way of doing it ?

 

 

 

Thanks

 

Is this a retrofit on something that didn't have battery backup previously?

The battery must be overloaded - are you sure it's not trying to also power the ROM?

[Richard H.]

Is this a retrofit on something that didn't have battery backup previously?

No, it's a cart for homebrew VirtualBoy games that require high score / level saving (see pic)

 

are you sure it's not trying to also power the ROM?

I checked, it's just putting power to the SRAM. I'm going to try with a larger CR2032 battery and see how that copes.

[Richard H.]

Fixed it . I'd left the Chip Selects floating, which meant it was going in and out of standby (in normal mode it burns through the battery).

 

Had it hooked up for a couple of days now and the coin cell has not gone down even 0.01V yet

 

I've made myself a replacement Wario so I can preserve my NIB one