After modding my Sega Saturn to use AA Panasonic Eneloops, I found a guide where someone modded their Dreamcast with rechargeable AAA batteries. The Dreamcast uses a rechargeable 3V lithium battery; I’ve seen conflicting sources on the exact type of battery. I’ve read it can either an ML2430, ML2032, or LIR2032. Since my Dreamcast battery seemed to be dead, I decided to do the same mod but with AAA Panasonic Eneloops. They have a minimum capacity of 750mAh which is 7.5x the capacity of the ML2430 mentioned above. It will be interesting to see if the Eneloops stay topped off in the Dreamcast; assuming the Dreamcast uses the ML2430 and charges at a rate of 1C, it would take about 7.5 hours for the Dreamcast to fully charge the Eneloops.
You can see below I used a 2 AAA battery holder instead of taping and soldering them together like in the guide.
I’ve been cleaning out old boxes of junk and stumbled on my forgotten Sega Saturn console. Sometime during high school I had taken the wires for the CD-ROM door switch and simply twisted them together to enable using the Swap Trick to play backup games. I decided to implement a better fix by soldering an actual on/off switch and also do a mod of the built-in battery. Unlike the Sega Dreamcast that came after, the Sega Saturn does not use a built-in rechargeable battery for memory saves; it uses a CR2032 lithium battery. According to this Sega Saturn Battery FAQ, the CR2032 has a capacity of 230mAh and will last 1-2 years in normal use or 19 days if the console is unplugged. This FAQ also discusses using other lithium batteries with higher capacities than the CR2032; I decided to try using Panasonic Eneloops instead. They are considered one of the best, if not the best, rechargeable AA batteries on the market; Eneloops have a minimum capacity of 1900mAh and can keep their charge while sitting unused for several years.
I went to my local Fry’s Electronics store to pick up a 2 AA battery holder, mini on/off switch, and some 3M mounting tape. The battery mod is straight forward; solder the positive sides of the battery holder and the Saturn’s battery contact together and do the same for the negative sides. If you get a 2 AA battery holder, make sure it’s wired in series so you’re getting 3V from the two AA batteries.
Since the Eneloops have a capacity of at least 1900mAh, it should theoretically last much longer than using a CR2032. I’ve had it running since yesterday July 29th; I will make an update in the future on how well it performs. You could also use AA Lithium batteries instead like these.
I lost the cover to the battery compartment so I just mounted the battery holder where you would normally see the model number of the Sega Saturn. You can also see the mini on/off switch mounted above the battery compartment area. Not the cleanest looking mods but it works.