Best way to power an n64 for a long time light weight

MaDnEsS · Post by **MaDnEsS** » Tue Nov 08, 2005 8:16 pm

I was looking at many different ways to power the n64 like sony cam batts rechargable AAs i would like to know what would be the smallest and lasts longests method for powering.

Metroid fan · Post by **Metroid fan** » Tue Nov 08, 2005 8:17 pm

Well you could try li-polys... but they are expensive.

MaDnEsS · Post by **MaDnEsS** » Tue Nov 08, 2005 8:20 pm

im not familier with those.

Turbo Tax 1.0 · Post by **Turbo Tax 1.0** » Tue Nov 08, 2005 8:21 pm

try a 7.2 volt Ni-Mh RC car batt pack they arent to big arent too expensive but they have a lot of ma

Metroid fan · Post by **Metroid fan** » Tue Nov 08, 2005 8:24 pm

Well they're incredibly light weight batteries that discharge a lot of power gamelver would know a lot more about them than me...

MaDnEsS · Post by **MaDnEsS** » Tue Nov 08, 2005 8:30 pm

how long do those rc batts last if im powering a psone scren two

Turbo Tax 1.0 · Post by **Turbo Tax 1.0** » Tue Nov 08, 2005 8:34 pm

the ones at rad shack have 3000 ma and just the right voltage
if you led mod the screen it consumes about 300 ma
and i'd guess an N64 consumes around 500-700 ma so a couple hours probably can someone else verify the N64 consumption

o and if you use the rc battery pack its way easy to build an integrated charger

superdeformed · Post by **superdeformed** » Tue Nov 08, 2005 9:00 pm

Turbo Tax 1.0 wrote:the ones at rad shack have 3000 ma and just the right voltage
if you led mod the screen it consumes about 300 ma
and i'd guess an N64 consumes around 500-700 ma so a couple hours probably can someone else verify the N64 consumption

o and if you use the rc battery pack its way easy to build an integrated charger

My portable N64 with the PSone screen in it draws around 1.1 amps total from the battery (backlight is modded with 4 LEDs and the 3.3v line is powered with a switching regulator). So, on a 3000mAh 7.2V battery, thats just about 2 hours and 45 minutes. It's probably more like 2 hours and 30 minutes max realistically though, due to the voltage drop on the battery. Radioshack also stocks a 3300mAh 7.2V battery pack, which would last whopping 15 minutes longer.

daguuy · Post by **daguuy** » Tue Nov 08, 2005 9:14 pm

what's more efficient, a switching regulator or DC-DC convertor?

superdeformed · Post by **superdeformed** » Tue Nov 08, 2005 9:36 pm

daguuy wrote:what's more efficient, a switching regulator or DC-DC convertor?

I have no idea really, but I think it mostly depends on the parts/circuit that you're using. The regulator I have (LM2576) is around 85-87% efficiency, but you can get ones up to around 94%. Gannon seems to know a bit about DC-DC converters, you can probably get a better answer out of him

.

Post by **marshallh** » Tue Nov 08, 2005 9:57 pm

superdeformed, I assume you're using a National or Fairchild part, would you mind describing the circuit you used for it? And where did you get your inductors (Coilcraft?) This brings back a horrible flashback of when I built a PC power supply for my car out of switching regulators (that was tough.)

daguuy, a switching reg. and dc-dc convertor are pretty much the same thing,. just different terms. It's like calling a computer a web browser and an email sender. It's both of them.

timmeh87 · Post by **timmeh87** » Tue Nov 15, 2005 7:15 pm

regarding li-ion polys, they have the highest enery density of any known battery technology.
(http://www.madkatz.com/ev/batteryTechno ... rison.html)

if you wanted to have the most power per lightest weight, this is what you should use. the best, best (read: space industry) ones can have energy densities almost three TIMES that of a ni-mh battery.
what does that mean?

it means if one pound of ni-mh batteries run your portable for 2.5h, then one pound of li-ion poly will run it for more than 6 (or 7!!)!

you should also keep in mind that all lithium ion batteries develop about 3.65 (average) volts. so you can basicaly use one (with a reg) for your 3.3v and two for your 12.

they come in standard "AA" size, as well as a range of cylindrical and RECTANGULAR shapes. i emphasize the rectangular shape, since it is usually quite low profile (thin but wide and long) and would be ideal for a portable application. the battery that the gameboy SP/ nintendo DS runs off of is a rectangular li-ion.

there are two major drawbacks to li-ion batteries though

1) they are much more expensive
2)
- if you over discharge them, THEY CATCH FIRE
- if you over charge them, THEY CATCH FIRE
- if you draw too much curent, THEY CATCH FIRE

(note. some exaggeration. but it is not like it has never happened before. it has. at any rate its real bad for them.)

so a somewhat complicated "protection" circuit is needed. some batteries have it built in. others dont.

Turbo Tax 1.0 · Post by **Turbo Tax 1.0** » Tue Nov 15, 2005 8:49 pm

woah i just saw some sweet li poly batteries at batteryspace.com 6,000 ma 3.6 volts 25 dollars a pop though and no charger

timmeh87 · Post by **timmeh87** » Tue Nov 15, 2005 9:48 pm

while on that site i found a large selection of protection circuits for anyone interested in implementing li-ions:

http://www.batteryspace.com/index.asp?P ... tegory=711

did you mean $250 dollars each?

these:
http://www.batteryspace.com/index.asp?P ... rodID=2157
ones look pretty sweet. 1500mah, 3.6V, and <i> the size of 4 credit cards stacked together </i> (i actually measured 4 card stacked together). so lets see. if you use two for you 3.3v and 4 for your 12v, then you'll spend 78+tax bucks for 3000mAh. ouch. good thing i can get these things for free from school

Post by **gannon** » Tue Nov 15, 2005 9:53 pm

$25 is pretty cheap, back when I started making a ps2p from a V4 I was looking at getting 6 or the 3.6v 2.2Ah cells here