LITHIUM POLYMER battary packs?

Dreamspawn · Post by **Dreamspawn** » Fri Dec 16, 2005 9:28 am

Ok i'm new to this whole make your own portable thing i have seen some of people work looked a few of the guides. I was browsing throught forums and bout a month ago guys were talking Lithium Polymer battaries and how effictive they are. This link was even give on where you could get some http://www.batteriesamerica.com/lithium_polymer.htm

I was wondering if A. Has nebody succesfully used these to power the N64p B. Which ones would you need? As in current draw 1A,2A,7A what??

The system i've been thinking bout building is one like the guy did where the screen/controler was made into the console. If i'm correct i would a 3.7v one for the monitor with a regulator right. THen 11.1V one for the console.

The reason i'm asking 2hours or so on a regular 7.2 or bunch of AA just doesn't sound practical. But they said on that thread that With these LPs that the system could be bout 6-7 hours. Thats more like it to me. Once i decide this issue i think i might just decide to jump in and build one but i'm looking for somthing alittle more practical then 2 hours or so. Also what is the biggest screen you all have seen used? i know if stuff it into the console the 5 in will proabably be the biggest but this is just a curiosity killed the cat ?

BTW great forums

Dreamspawn · Post by **Dreamspawn** » Fri Dec 16, 2005 9:38 am

http://camerahacks.10.forumer.com/a/che ... t1964.html

Thats the one i'm looking at making mine look like.

timmeh87 · Post by **timmeh87** » Fri Dec 16, 2005 11:27 am

most of the li polys on that site are relatively low densitry. youd get about the same life as you would just from a normal nimh RC car pack, without the risk of them exploding in your face.

if you KNOW the risks of using li-polys, and you know how to properly charge and discharge them, and the consequences of doing something wrong (basically they explode no matter what you do wrong), then id go for something like this:

http://www.batteryspace.com/index.asp?P ... rodID=2169

youd need to stack a few in parallel to get 7.2v, OR you could get a step-up DCDC- converter from another thread on this forum.

there are premade protection circuits on that site too, if you dont know how to make your own.

Post by **gannon** » Fri Dec 16, 2005 11:35 am

you mean series

Dreamspawn · Post by **Dreamspawn** » Fri Dec 16, 2005 11:48 am

Ok so thats not a good idea i thought if i were to get them i could get that safe charger that stops when they are full. What would you suggest for a battary pack that would last atleast like 5hours.

Post by **gannon** » Fri Dec 16, 2005 11:51 am

Depends on your screen draw, but I'll just estimate a n64p with modded psone lcd would draw ~ 2A. So for 5 hours you'd need a battery pack that would hold 7.2V @ 10Ah. Cheapest way would be to get 6 NiMH D sized batteries, but that'd weigh quite a bit.

Dreamspawn · Post by **Dreamspawn** » Fri Dec 16, 2005 1:15 pm

KK ben used 8c battaries on his i think from the pictures on here. I don't think that many would fit inside the N64 case though Also screen it seems that the psone lcd is a popular choice. Ne other option with lower power draws? Worst case scenario i could a smaller screen aslong as its no smaller my PSP screen i can live with it.

timmeh87 · Post by **timmeh87** » Sat Dec 17, 2005 12:40 am

yeah... series

superdeformed · Post by **superdeformed** » Sat Dec 17, 2005 1:03 am

gannon wrote:Depends on your screen draw, but I'll just estimate a n64p with modded psone lcd would draw ~ 2A. So for 5 hours you'd need a battery pack that would hold 7.2V @ 10Ah. Cheapest way would be to get 6 NiMH D sized batteries, but that'd weigh quite a bit.

Lies!

. With a modded PSone screen and a fairly effecient regulator/DC-DC converter for the 3.3V line, the draw should be somewhere around 1.1A (without the expansion pack). If you have a regulator or DC-DC converter in the 90%+ efficiency range, then the normal .9-1.2ish amp draw on the 3.3 volt line would only be around .4-.6A on a 7.2V battery. Add about 300mA each for the screen and 12V line, and you've got a somewhat managable load.

With a current draw of around 1.1A, you might be able to get away with 4 and a half hours out of 6 5000mAh NiMH C cells.

Post by **gannon** » Sat Dec 17, 2005 1:10 am

Last I checked while running Starfox, the n64 drew 500mA @ 5V and 1500mA @ 3.3V. That's not using a single voltage, that's straight between those lines and the psu.

Post by **marshallh** » Sat Dec 17, 2005 10:39 am

Also, you need to know that as voltage goes up, amperage goes down (for the same amount of power (W).

W = VI

So, the 5v line draws 2500 mW and the 3.3v line draws 4950 mW.

Add them up, you get 7450 mW.

Now, assuming the battery voltage is +7.2v, 7450 / 7.2 = 1034mA.

So, you could theoretically get 3.18 hours from a fully charged 3300mah r/c car battery.

This does not include the screen however. A modded psone screen takes 350ma at 7.2v with sound low.

So total draw is 1034 + 350.
Thus you get 2.38 hours with screen too.

I hope you can understand how this works

Turbo Tax 1.0 · Post by **Turbo Tax 1.0** » Sat Dec 17, 2005 10:52 am

you could just get two li poly battery packs from www.batteryspace.com i got some 6000 ma ones for my snesp markII

daguuy · Post by **daguuy** » Sat Dec 17, 2005 11:04 am

another thing you could do to increase efficiency is use a dc-dc convertor for the 3.3v and 5v. you could also give it some over/under clock switctes so you could switch it to 62.5 mhz (when it's off of course) so it'll draw less current

Post by **gannon** » Sat Dec 17, 2005 1:17 pm

marshallh wrote:Also, you need to know that as voltage goes up, amperage goes down (for the same amount of power (W).

Yep, it's not amperage that matters, it's watts.

jeep · Post by **jeep** » Mon Dec 26, 2005 9:10 am

Well, I did a little review about my Li-Ion battery pack. Honestly, I'm happy about it

. This is the one I got:
http://www.batteryspace.com/index.asp?P ... rodID=1207
With the shipping, it costed me about 60$ Canadian, but with 3 rc battery connector. The shipping is 15$ US in Canada, so try to get an offer with free shipping

I recently bought the Smart Li-Ion 7.2 V charger and the 2400mAh Li-ion battery with the PCB. What I can say is that Iâ€™m quite impressed by the product at the moment. The charger seems to be of great quality and it charge in 2 to 3 hours the battery pack. The battery pack is really easy to use and it seems quite safe with the PCB. After experimenting with it for a couple of days, I had no problem at all and it was powering really well my hip gear screen + famiclone. The screen and the famiclone have been running for a couple of hours and itâ€™s still working well! The shipping was not too long, considering I live in Canada (about 15 days). Buying it was not a problem; the price was cheap for the battery considering I was not able to find any in my local city of Laval. The shipping seemed quite high at first, but considering it is send by airmail and to another country, itâ€™s acceptable. Using a credit card doesnâ€™t seems to have been a problem, even if they says it can be one in the FAQ because I received an email 2 days after seeing it had been send via airmail. Anyway, as soon as my project is completely done, Iâ€™ll test more this product and tell you if it survive my project. Anyway, even for those that need a different battery pack or just battery related things; check out www.batteryspace.com , they have a really great selection of those. The have NiCd, Ni-MH and Li-ion. They also have some great deals on AA battery, and some of their offers have free shipping. For those that need Cell-phone, laptop, rc car/plane or bight light, this is the place to go because they are really specialised in those things. Anyway, itâ€™s for you, but I know Iâ€™ll buy my next battery there. Probably some AA batteries because they are about 1$ each, and have a great 2300 mAh capacity ! Anyway, for thos that needs a battery pack, you should try them since I am quite satisfied with my purchase yet. Beware though, it's says they are not responsible for lost shipping in the agreement, I didn't have a problem and didn't saw anyone with one, but I was a little bit frightened about that when I first saw it.

Anyway, for those wondering, they actually pay people to review their product, even if it's a negative review. Mine is positive because I'm happy with my batteries.