Battery questions.

[Arsies]

Hello

I'm new to saber building. I introduced myself in my previous post where y detail a little my fisrt saber project. (you can read here: http://forums.thecustomsabershop.com...e&goto=newpost )

My question is about battery.
As i told in my previous mail, i'm powering my sabers with 3xAAA alkalines (4,5V) so I estimated a 40 minutes duration of the power as I'm using a 1500mah, 4,5V LED's.
Problem is that I want to get more working time but I have some problems.

First of them is space, Although I can add another pack fo 3xAAA in parallel (so i can get x2 time), it's not the best option since Alkalines cost is so high to change them every 80 minutes.

Second is that I can't use rechargeable batteries as they give only 1,2V so 3 batteries will give me only 3,6 V and my leds work at 4,5V, yeah I know there are some alkaline rechargeables at 1,5 V but they are just 800mah and reviews told that most of them doesn't have even half of that.

Third is that I can't use 7,4 V LiIon batteries as I want to use nano Biscotte that support as much 5,5 V I think. I would like to use PC but it's a lot of money for now, maybe in the future.

So... I'm obviously not an expert in batteries but I readed a lot (really a lot) and I still have no idea of a possiblesolution... except using another soundboard that could work with more volts that nano biscotte (maybe I'm using not the best leds for this board, but as I said in my first post, getting materials in Spain at afordable cost is hard)

[Silver Serpent]

Use 4x NiMH batteries for a 4.8v pack. It's the only viable option that fits your requirements. You'll save money on batteries, and can easily keep a few charged batteries around as spares. If you have the room for a 6xAAA pack, you should have plenty of room for a 4xAA pack.

[Arsies]

mm yeah, I didn't thought in that, somethimes the best option is the easier one :-/

[FenderBender]

Or use ONE 18650 size Li-Ion battery. You'll be right at the required vf of most LEDs and that's what the NB was designed to run with. Alkalines suck. Period. They're not efficient and just like NiMH/NiCD batteries, the voltage of your packs goes down IMMEDIATELY when you put a load on it. Not only that but you're thinking capacity, when you should also be thinking about discharge rate. Alkaline AAA's at BEST put out about 800ma discharge. That won't be very impressive with sound and a high power LED that wants at least 1A and the board needing another 300ma. Li-Ion is the way to go, plus on 18650 will take up a LOT less room than all those other cells, and TCSS just happens to have them in stock here

[Arsies]

I can't use a 18650 as it's 3,7 V and (as I said) i'm using 4,5 V LED's, so it hasn't enought Voltage to run them (and finding Li-Ion batteries in Spain is hard in the best case).

In the other side, I cheked the 4 AA option and no battery holder fits into my pvc hilt, as it has 25mm diameter and most AA holders have 26mm. (at the end with NB inside I can's use 6xAAA alkalines neither, I haven't enought room)

The only option for me is to make a custom battery soldering 4 NI-MH batteries and making a custom rechargeable port, that honestly I have no idea how to do :P

The positive point is that I'm learning a lot so future saber won't have this problems.

[FenderBender]

What LED are you using that's 4.5v? Even a high power bin Rebel Green would only be about 3.7-4V. I'm not sure why that would be your only option. Companies like Deal Extreme sell to pretty much anywhere (they have distribution centers in multiple locations). I would do some more research before settling for an inferior power solution. We would also like to know more about what LED/s you're using.