Sega Game Gear - Internal chargeable battery mod

Sega Game Gear - Internal chargeable battery mod.

So I had repaired a couple of those huge battery packs and lugging them around wasn't fun so I thought how about doing a mod that replaces the need to use them. I know I could use rechargeable batteries but taking them in and out, remembering to put them on charge and if your like me loosing them is a pain.

The total build cost was around £11 and took about an hour too do.


This image shows the internal wiring and circuit board

This image shows where I located the batteries

This image shows it all working

All the wiring has now been tidied up and run along the sides and is now held in place, put some grounding tape over the circuit board to stop any possible shorts.

The batteries are two 3.7v 1100mAH Li-Po batteries, these will then take charge from the DC jack already in place and charge up and give around 8V. So far I have had the thing on about 4 hours from a full charge and it is yet too die.

Going to add a DS Lite back light mod to this to increase total play time from a single charge.

 

Nice work! Also, I highly recommend getting a replacement screen from a guy on AtariAge. His uses the digital video signals the GG generates instead of a composite video mod. It also has a DAC built in that outputs RGBHV to an optional VGA connector.

 

Can you post a parts list and wiring. Are they wired in series or parallel?

 

Nice work! Can you give a littlemore detail? Id like to do this to a screen modded game gear i just finished.

 

Same! Lugging an external 1800mAh battery pack can be tiring.

PS replace that LCD!

(not the best picture) New LCD and unlike the older RGB hack, McWill mod does both GG and SMS full screen, has scanline mode for old look, and can be connected to a VGA dispaly as well. Plus wiring is not touchy like the old RGB mod where the clock wire had to be fixed in a certain way to avoid interference or problem.

 

Great work man. Can you put together a parts list? I might wanna do a modified version of this to a DMG gameboy, but if I find my GG I'm definitely doing this to it.

 

Very cool work! I actually did a mod just like this not too long ago and have an LED backlight mod guide over here:
http://www.smspower.org/forums/15519-TheNewImprovedGameGearLEDBacklightMod#87095

What circuit are you using to charge the batts? Li-ion require a special charging cycle or they will be damaged. I actually hooked my batteries up parallel (3.6v) used a DC-DC step up to 6.5v (GG runs well below 7.0 and saves power) and used this board for charging:
http://www.ebay.com/itm/TP4056-1A-L...USB-/111619711563?hash=item19fd0da24b&vxp=mtr

that way I can power it off USB your method is MUCH less work though!

-Segasonicfan

 

Hi guys,

Sorry for the late replies. Will get something together when I am at home just at work at the moment.

Thanks for replies too.

 

Looking at the first picture, that little figure-8 board near the battery compartment is the lipo charger and 5v regulator.

 

Shhh don't spoil it Going to do a full write up. Will be doing a couple more too sell on as I currently do with the faulty ones, so will get some pictures whilst I do the process.

 

That's a li-ion charge/ discharge controller- very unlikely it is a charger. The SOIC chip is the regulator IC and the other is the switching FET for discharge current regulation. I have some boards like this. It does not include a 5v regulator either, he is using 7.2v to give to the Game Gear DC-DC board which has its own regulated outputs of 5v and 34v respectively.
A proper charger would be larger than that board, especially if it going to balance the cells correctly.

but heck, maybe theres extra chips on the other side we can't see? gotta wait for the write-up.

-Segasonicfan

 

That's a killer Idea, wanted to do something like this myself, but wasn't sure it was possible. My Game Gear's caps all need replacing, and I figured I do something like this while I had it open.

 

Double check that you're not over discharging the cells, as lithium batteries really don't like that.

I can't imagine the run time being much more than 4 hours with the 1100mah battery pack

 

Can you underscan the image using this mod? The scaling looks absolutely awful Otherwise it looks really, really nice. But I couldn't stand playing something that looks that rough :/

 

If its the same board I have, then yeah, its doable as well as adding in scanlines via a button combo.

 

Great

 

Hey guys,

Still not forgotten you, the last batch of batteries I have ordered got held at customs, still awaiting on them to arrive.

Will update you again shortly.

 

Any updates? Or a guide?

 

Woah, woah woah! I have to stop you here, my friend. These packs are in series, right? If so, you need a balance board to charge them! They will be fine for maybe 50 cycles, but after that, those cells will become unbalanced. Then they will start puffing and eventually explode. What you need, is a circuit just like in this article.

https://learn.adafruit.com/multi-cell-lipo-charging/simple-balance-charger

 

edit:
You can get Lithium batteries which already have protection, if you need to save space