Where to add battery to SNES cart that doesn't have one

Dark Jaguar

I'm trying to use a few boards from busted cart cases for personal repro purposes.  One has just about everything perfect, but lacks a place for the battery.  Where would I add one in order to add saving to this cart?

TheIceManJaxFl

Hmmmm. The battery is so that the sram or save ram can stay powered by the battery. If your using a board that does not have a battery, chances are it doesn't have the sram. So adding a battery wouldn't work.

Dark Jaguar

It appears to have a 512k RAM module.

Koopa64

picture of the board?

Dark Jaguar

https://lh3.googleusercontent.com/iBPfcnKk2ebmCs5sBvR4vm5DTS_uEI3NYtdGud-GA0gkq2OmBay9UXadFR_J8vVLN4scEsDqNZDJ3ndm_W6Mp6GzR7DlPe-3kY9WxJGsZ0HggP5rGV0HY4GwHHwcnSkBom_qzBGxJ0O2mKMaElJwhHucnAaupx7rikRkjdRAF3DULGvx4z64INhR2jTIxdI6p6iAfowi3RYQcofZVAehoaf4SVYnBbyM4OeJVd7lfiXkfUo4kYHpZb3tH1sp5z7AchQoyue3bGcwRhiDHDehRMbJnZxHvuqbw3qqm8a9X8IWa45TzpERPPZKO3eAHmttQsv2GrxM2VcHj3XofNAVmqxMte082kWapDO0YZu2d3kq9FyoM1Dv2fQ7kJptTVKKyY1V5Or9HehRoY7Lw9L8yFQrXmWTysNEWfntzAjZ8w7-o9I_Nheu819SmprUdFP9_8N6L3WlIRe6kRK_lmRNr7FO0sQbiMwYmgcUXLipc6KT5TNhmHOH6ZFChAuB_PnCNWCjaBfuXhuF6XAtteMgRA4XyDXA8Vd_FfPN-MoJqTCZ6jKEcDzecxuPPLHnD0BfuRu60x-4aAIEXzATfG7oZYzSb4Eb3OzuoTwiq9bW3I3jLSodZ8x-oRFV1m4Ku2OuJsyQYIAKH9HrdKc_NYJr8PFXnq06PXW1=w1215-h911-no



https://lh3.googleusercontent.com/w5RSnu5uOACLZGux8wE7JIoI_LNHj28uAZEIjiQm__e06ra0AE11NU9w7BFxafA2tMySoIJHxEEdBA-2K4-Vm5uBJomLpWgENn0JqMdthejm-ffYT8n6IRuQNyalIfNAI76QW8AHtM5SLKTwAsWa3J7pwbjs8a4yUaDxWhzHLVmXPYJukEwc2JZlwyrg1ff6wuIcEBaO1_loVi6SjJLL24PiehJLNzO6w2EX3adiT0YQ1iz_MvAP1K8zJFV-I_LBYRylDHbHfUntoqKAI1hsXqy-Kpp_CsmtLBLzUIgbOzYog6lzTpuZhuTi1h58-lyRR9y6f4I32jSHHAOqeIYVMhBa7C92KN7YWHM0CONz5DjJgJtsQbzDt4WHlDJqNdDcScK9lL3mNSHxZwsuCclvhEawOWX8dp6nbdosMERmGKuF2_tU1SokLq6FaorJb-D0K2BC5Egghqi9tXStHxIJ1-ZHmtYJVXkEXfbNr4yDhemJ59N_NQImv_Sj1GOsL71nNsgrUeW-HYR0PSFF6k4QEgp6Mxe9VE48AX9axQWYUV7bd30PxOfTBzGNZaWntAYzMY0mLAPrr3eR4dJZGV5HsGVpHxf_73qlogXVGXWh7h0BtnQDCKCI-n8zda9xvNPmXv6n-DLX5iyx71O0OOr9u0sx7cDSTNxB=w1215-h911-no



You can probably tell what I'm going for here. I decided I wanted to go ahead and make a Starfox 2 repro for myself, using a spare board I was ok with gutting for the job. Yeah I know Stunt Race FX is preferred, but I only have one copy of that and I don't want to gut a good game if I can avoid it.

Koopa64

Rest in peace SNES doom.



that said, I think you'd have to connect a battery to the chip marked LH52A512NF somehow. Diodes and resistors maybe. I think the voltage pin on the chip would have to be lifted in order for the battery to work for years instead of weeks/days.

Dark Jaguar

I got the chip off clean, so I can always put it back on if I want to. I had heard that lots of people had made custom SF2 using Doom boards in the past, but for the life of me I can't find any guides as to where to add the battery. Did most of those people just run it without the save battery? If all else fails, I can fix this up and stick it back in it's busted red case, or even swap the SRAM chip with one on a Yoshi's Island board, or just go the Stunt Race FX route, but I really don't want to sacrifice actual good games for this if I can avoid it, and I had an extra doom but would have to buy spare Yoshi's Island or Stunt Race FX.



If anyone has a quick guide as to where and what to connect, I would be open to it. My aim in any event is to use a battery holder no matter which solution I have to go with, so that I can easily replace that battery. From the sound of it, the way SRAM on non-saving boards is wired would damage the battery if left as is, so I'll keep an eye on that. I've been working on my soldering skills, but my ability to read a schematic is pretty much null, so I welcome all the help I can get.

Ice Man

Not only will you need a battery but also a BA6162 + 1k ohm resistor and connect them properly. Otherwise the game won't save at all.