Sega Nomad Battery Pack

Started by -Bistrobean-, April 06, 2006, 05:31:49 AM

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Hello there all,

I have a rechargeable batterypack  for the Sega Nomad, its a Nimh 7.2V 1600mAh batterypack.

All of the six batteries are dead. Can i just replace the batteries with new ones.

How do i suppose to do this without blowing up my Sega Nomad?

Is there a Batterypack mod somewhere on the net?

Many thanks! :)



just check the amount of cells in the pack, and check on and see if there are suitable replacements.  I did something similar with teh battery on an old laptop, i replaced the dead cells in it with rechargable nimh AA batteries.  It worked pretty decently.


Actually, a nomad has a 7805 regulator in it, meaning you can input a voltage between 7 and 25/35 so you can just put in AA's or a batterypack from radioshack.


Gunnex is right. The official Nomad battery packs had some regulator circuitry to accept the 9 volts from the 1602 Genesis AC adapter for charging. But it would be simple to adapt any other rechargable power source and connect it to the power output panel on the battery pack. It's not necessary to replace the cells one-for-one and reuse the regulator circuit.

Sony makes a Lithium-Ion battery with the model number NP-F530 that's good for this kind of use. Cheap, plentiful, and outputs a steady 7.2 volts good for all kinds of system. Ben Heckendorn likes using them for his portable hacks.

I'm too lazy to produce a Wiki page with the basics of rechargable power sources, and the pros and cons of all the different types of batteries. Maybe someone else has more free time?

-KKC, hacking Wyse terminals...


Kendrick, I'm in the process of making my own battery pack for the nomad, which as of now is 6 D-size alkaline batteries plugged into the AC jack, and is able to run the the system fairly well.  However, the system will shut off well before the batteries are dead, which I think is due to the voltage dropping too low when they have been under load for a while.  I was wondering if the regulator you mentioned is actually within the nomad itself, or if it is on the rechargeable battery pack as you had originally stated.  If there is a regulator in the nomad, then I would be able to just add another battery to make it 10.5 volts, but I don't want to try it until I have confirmation that this is within the nomad's input tolerance.  Otherwise, I'll have to find a regulator of my own.

On a side note, the reason that I'm using D's is that my mom has a cabinet filled with them, and the only thing that uses D's in the house is a flashlight, which is hardly ever used.  I might as well use them up before I switch to something more practical.


Just out of curiosity, why are you connecting the battery output to the AC adaptor jack rather than to the battery pack contacts? I'm guessing that the power input at the AC adaptor jack is more heavily regulated than the battery pack input, just by virtue of the messy, noisy power that you might get in an average American or European home outlet. That would also mean more potential power loss, since the wattage coming out of a transformer would be typically pretty constant. If you're making your own battery pack, you should model it on the AA battery pack that shipped with the Nomad and connect it directly to the contacts on the back.

-KKC, up too early.


It's simpler to just solder an adapter plug to the batteries and plug them into the system that way, rather than to try and build something that will attach onto the back of the nomad.  Maybe when I decide to make a rechargeable pack I'll have it mount onto the nomad, but as of now there's no really decent way of connecting 6-7 D-size batteries through the rear terminals.  My battery pack won't be attached to the nomad; it'll most likely set on my lap or on the floor, with the cord plugging into the top of the nomad.  And as I've mentioned, I have about 40 D's that are just sitting in the cabinet, so I might as well use them up before I make a rechargeable battery pack.


Thing is, the back of the nomad is a lot more stable than the power jack. Most nomads (well, the two i've seen) tend to reset if you jiggle the power connector too much.

   Also, you can just wire up a Sony camcorder battery and expect it to charge and everything? I've got like 4 dead rechargeable power packs lying around and this is very good to know.


You can do what I did: acquire a "torpedo" type Game Gear battery pack (which most likely doesn't work at all by now), buy a 7.2V RC car battery pack at RatShack, and then simply swap the internal GG battery pack's battery with the one you bought.
I found this idea somewhere on the internet and performed it years ago, and it charges and works perfectly.
I also made a 6-AA battery pack out of RatShack parts (a 6-aa holder, some thick wire, and a suitable Nomad male adaptor jack) and a bunch of new NiMh batteries, and that worked just fine too, although I had to use a rubber band to keep it from falling off my Nomad. It was cool too, since it made the Nomad look like a bomb...


Personally, I'd just put modern rechargables in the normal battery pack.


The nomad a chargable battery pack, and a case that held AA's. The case vertion is the one I want so I can put madern rechargable AA's in it, but I can't find the case sold apart from a system. lol, when I bougth my Nomad I had no Idea The AA's were external. And the multi adapter they sent didn't work. Im curently using a sega / snes adapter i recently bought, spliced with the plug off my portable phone base.... hey, it works when nothing from wall-mart did.


Well as for me, i have a rechargable batterypack with dead batteries of course (batteries from 1995 lol) These are 6 NiMH 1800mAh batteries, i replaced them with the exact type of battery. I replaced them one on one which means even the required components are soldered on the right place.

The only thing is that the voltage i get on the output is very low, checked everything, untill i decided to remove all components and solder the wires direct to the output.

It works though, charge within 2 hours, and hold more than 3 hours of play. The only thing is, the nomad shuts off without a warning. What do you expect from playing 3 hours constanly lol!



1800mAh NiMH batteries special size, forgot the type.

It works though 2 hours of charges hold more than 3 hours of play. The only thing is that Nomad shuts off without any led warning, aw hell what can i expect from Nomad for play more than 3 hours contantly, LOL :)