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.

[Arsies]

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.

yeah, the problem is that i need to build 6 saber for a wedding and my intention was to keep them under 30$, but In spain is hard to find some materials and shipping cost from USA to spain is around 48$ (that was so much of my budget at first, now I think that i could ordered here in TCSS and at last I should save problems even if sabers could be 7$ more each one, but, hey, tell you that to my friends that doesn't want to pay more!). And I had not so much time as it is next month!

As I wanted to save shippings I needed to buy in one or as much 2 Spanish online stores to save costs, and I couldn't find any store that had ALL that i need (or at reasonable costs, as I told in another tread a shop asked me for 15$ for ONE white led, even more for blue or green... things looks so easy in USA where you can find almost everything at reasonable costs)

It took me around a month finding all materials and wasn't those i wanted, just close to. My leds are 5W 1500 mah Huey Jann electronic and for sure are not the best option.
If I keep out the budget limitation everythig becomes easier. I know where to find more huey leds working at 3W 700 mah at just 5 $ (and in fact I'm really happy wit Huey led's, work really great if you only look at brightness), or where to order luxeon leds, it's easy as you say, but that will be for my own saber in the future and without money limits.

Maybe as I didn't know anything about electronic I could look better for that but at first I only knew that more lumens = more cool XDDD

[FenderBender]

The Huey Jann 5W LEDs are VERY similar to LEDengin LEDs and I have used a few of them myself. They will work JUST fine with an 18650 cell, but not a 14500. NiMh won't really deliver the current you're going to need to fully power the Huey's either. I would really try to find a way to get yourself some DX Trustfire flame wrap 18650's, I'm telling you, that will solve so many of your issues.

[Arsies]

The Huey Jann 5W LEDs are VERY similar to LEDengin LEDs and I have used a few of them myself. They will work JUST fine with an 18650 cell, but not a 14500. NiMh won't really deliver the current you're going to need to fully power the Huey's either. I would really try to find a way to get yourself some DX Trustfire flame wrap 18650's, I'm telling you, that will solve so many of your issues.

But a 18650 is only 3,7V isn't it? Do it really work with 4,2-4,5 V leds? Why?

Maybe i'm asking domething stupid but I really don't understand it :-/ and in fact a 18650 it's CHEAP, I can find it for about 12$!

[FenderBender]

A fully charged 18650 will be over 4v and then go 'down' to 3.7v after a while. Most LEDs are capable of running off of a single cell. Huey Jann LEDs are almost identical in specs to LEDengin and I have used several of them. You'll be fine with a single 18650, trust me. You'll need to resistor any Red or Amber LEDs (if you're using those), but cool colors (blue, green, white etc) will be just fine. You'll be much happier in the long run.