Naomi DIMM battery replacement

OldFoo · Post by **OldFoo** » Fri Dec 07, 2007 4:49 pm

A warning of sorts: these batteries come with some pretty hefty warnings concerning toxicity and explosion - probably a good idea not to think of them as AA batteries you played with as a kid - and do take the effort not to short-circuit them while you assemble your new pack.

The Naomi DIMM has a 3 wire battery pack consisting of small PCB and 2 x Panasonic CGR18650H cells. The H is probably some rating, I used CGR18650CF's which have a bit better capacity. Search for CGR18650, or just 18650 and you should be able to source some locally.

The pack is connected like this:

Open the DIMM and disconnect the battery pack:

Strip off the outer plastic, and you should end up with this:

Desolder the PCB, be careful not to short the battery:

Assemble the new cells with the cell spacer and some electricians tape. Solder the metal part from the old battery pack to the new cells.

Add some more tape:

Solder jumper wires to B-, B+, and BC.

Tape it up, and you're done:

Thanks to InvZim of KC for this :smt007

OldFoo · Post by **OldFoo** » Fri Jun 20, 2008 5:20 am

I know this may have been thought of, but is it possible to use a AA holder? and just solder it to the connections instead of using tape? then you could replace the purple batterys alot easier, just pop off the holder door and replace them with no complex soldering. (Correct me if they are too short/long, because they seem fine from looks.)

OldFoo · Post by **OldFoo** » Fri Jun 20, 2008 5:53 pm

The batteries are not the same physical size as AA types (they are longer), so you couldn't fit it into a AA holder.

OldFoo · Post by **OldFoo** » Tue Sep 01, 2009 10:55 pm

AA's wont be the right voltage either. AA's are 1.5v. The LI-Ions are 3.7v each (in series = 7.4v)

OldFoo · Post by **OldFoo** » Wed Sep 02, 2009 10:03 pm

He's not asking if he can use AA's instead of the original batteries. He's asking if a AA battery box can be used instead of soldering.

OldFoo · Post by **OldFoo** » Mon Mar 29, 2010 10:07 pm

hi

have you any complete ready that you can sell me?

mo

OldFoo · Post by **OldFoo** » Sun Apr 04, 2010 8:50 pm

hi

when i search 18650 they are all 3.7 volts

on the sega battery it says 7.2 volts

any ideas?

OldFoo · Post by **OldFoo** » Sun Apr 04, 2010 10:09 pm

justniz wrote:AA's wont be the right voltage either. AA's are 1.5v. The LI-Ions are 3.7v each (in series = 7.4v)

OldFoo · Post by **OldFoo** » Tue May 18, 2010 11:20 pm

solder doesnt stick well to battery surface???

OldFoo · Post by **OldFoo** » Thu Jul 01, 2010 9:00 pm

i just did this two battery packs, i get a ton of used laptop batteries that usually have the pigtails in a perfect place to put the little board on the battery

Sega-Naomi

Naomi DIMM battery replacement

Naomi DIMM battery replacement

dimm batterys