Naomi DIMM battery replacement

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OldFoo

Naomi DIMM battery replacement

Post by OldFoo »

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:

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Open the DIMM and disconnect the battery pack:

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

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

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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.

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Add some more tape:

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

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Tape it up, and you're done:

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Thanks to InvZim of KC for this :smt007
OldFoo

Post by OldFoo »

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 »

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 »

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 »

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 »

hi



have you any complete ready that you can sell me?





mo
OldFoo

dimm batterys

Post by OldFoo »

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 »

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 »

solder doesnt stick well to battery surface???
OldFoo

Post by OldFoo »

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
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