PC Engine LT Battery Pack --- UPDATE

[wolfman]

Since I wasn´t satisfied with being tied to a wall adapter, I made myself a power pack, that would be sufficient enough for longer gaming runs. Since I want to use the IFU + LT + CDROM2 (the latter not working at the moment) I thought a pack big enough to handle all of them would be nice.

I thought maybe someone might be interested in this.
I built my own portable battery pack out of these things:

1x Atari Lynx I Battery Pack
6x Tecxus NiMh 9000 mAh/1.2 Volts
2x Adapter Cable with DC connector plugs
2x Plugs (1 small for LT, 1 bigger for IFU)
Cables, 4 mm2 diameter
some soldering involved
some dremelling involved
Epoxy
1 DC power jack (as charging port)

The original pack has some parts inside that aren´t needed and unnecessarily eat up space for cables and connectors, so I removed with a dremel. You don´t have to remove the original contacts if youd on´t want to - I left them in and they were quite handy to solder to. Then I had to dremel a hole for the DC charging plug and I took out the original cable meant for the Lynx I and replace it with a twin-DC-adapter cable, where I can change out the plugs (!), if I want to use on another console.

Thats it!


EDIT:

I was unhappy with the my first approach, so I made another attempt. Since there is a cutout on the CDROM2 due to low voltage (the unit needs a stable 9V support), I was looking for a small solution, that would fit into my existing accupack. That way I would get a much longer and reliable gaming run.

On Ebay I found a tiny step-up converter board, that is very cheap. I bought a handful - just in case so that I could replace them easily:

http://i01.i.aliimg.com/img/pb/124/470/790/790470124_335.jpg

Setup is as easy as can be. You just need to solder the power leads from the pack to the input pins, and the leads from the output cables to output pins respectively. Adjustment of output voltage needs to be done with a screwdriver (that little copper screw in the lower middle of the picture) and a voltmeter to match +9V.

Output voltage is very very stable until around 6.6~6.4V measured on the accupack directly - which is roughly 1.1V/cell. Then the screen on my LT would change in brightness, and the CDROM2 would cut out. Actually I get reading/tracking problems on the CDROM before, which is a good indicator of saving the game ASAP 

That´s what the pack looks like now on the inside:

https://www.flickr.com/photos/65709578@N06/14007247373/
https://www.flickr.com/photos/65709578@N06/13987251505/
https://www.flickr.com/photos/65709578@N06/14007245953/

Efficiency of the circuit is really high, I´d say around 85-90%. I get around 4.5-5 hours of gameplay out of it NOW, with the 5-player-tab and a gamepad connected!

[wolfman]

And this is what it looks like in action 

[ZueriHB]

How long does it last until the voltage drops to low and the LT screen goes all wonky?

[wolfman]

Well I don´t know, but maybe some math might help.

9000mAh, 7,2 Volts. Afaik the LT consumes around 700 mAh, operating internally with 5Volts (which are stepped down from usually 9Volts).

The IFU needs around 1400 mAh, plus the CDROM with another 750 mAh.

So:

700 + 750 + 1400 = 2800 mAh roughly. 9000/2800 = a little less than 3 hours of gameplay I´d say.

Haven´t tried it yet, since I am still waiting to get my CDROM to work for a complete test. But at least for the LT is waaaaay enough power to run for hours.

[wolfman]

With the step-up circuit added, gameplay is up to ~5 hours, constant use of the CDROM2 included! 

[EvilEvoIX]

Great work!

[hoobs88]

Can you make another one of these and sell it to me? I'd like to be able to make my LT setup more portable!

[wolfman]

Can you make another one of these and sell it to me? I'd like to be able to make my LT setup more portable!

Sure, but it won´t be a cheapie. What are you willing to pay? ..... (insert here), shipping excluded 

[csgx1]

That's really cool.  Nice work!  5hrs run time is outstanding, especially with the CDrom.  If only I had an LT.

You'd definitely be attracting more ladies with that setup on the subway than this guy ...

http://www.pcenginefx.com/forums/index.php?topic=12270.0

[wolfman]

That's really cool.  Nice work!  5hrs run time is outstanding, especially with the CDrom.  If only I had an LT.

You'd definitely be attracting more ladies with that setup on the subway than this guy ...

 

[turbokon]

Now that I just picked up another LT, I will try this mod.

[tggodfrey]

Very nice Job wolfman.  The Runtime with the CD is what makes this so impressive.  I would have expected the consumption to be higher on the IFU setup.  Congrats and thanks for posting the info.

[Desh]

This is really cool!  I've been playing with battery packs and I am still perfecting circuits on modified Sega Nomads.  My pack setup fits inside the Nomad itself and runs 7.4v 2800mah.  This makes it good for about 4 hrs. of gameplay.  My downside is finding a suitable charging unit that will charge faster but that also has built in over charge protection as the cheap li ion cells I'm using do not have internal protection.  As it sits it takes about 2 hrs to recharge my pack from dead.  The Turbo Express seems to draw similar power to a Nomad so once I have it perfected I hope to get my hands on one and use this setup.

[wolfman]

Now that I just picked up another LT, I will try this mod.

[wolfman]

This is really cool!  I've been playing with battery packs and I am still perfecting circuits on modified Sega Nomads.  My pack setup fits inside the Nomad itself and runs 7.4v 2800mah.  This makes it good for about 4 hrs. of gameplay.  My downside is finding a suitable charging unit that will charge faster but that also has built in over charge protection as the cheap li ion cells I'm using do not have internal protection.  As it sits it takes about 2 hrs to recharge my pack from dead.  The Turbo Express seems to draw similar power to a Nomad so once I have it perfected I hope to get my hands on one and use this setup.

I am using a 45 EUR RC charger, amps/voltage/cell type switchable, with a customized power jack. Anything will do, as long as it provides enough amps to charge the pack. I am using the "Expert Charger" from Carson.