Buying/making a charger

[Ursa]

I've ordered a bunch of saber parts for a LED strip blade (should be arriving in a couple of weeks) and I'm looking for a charger for my battery. I was just wondering, would it be possible to buy something like this (http://www.aliexpress.com/item/Dual-Smart-Battery-Charger-for-18650-Rechargeable-Li-Ion-3-6-3-7V-POWERFUL-BLACK/32242953037.html), cannibalise it, and wire it up to my battery pack?

This is the battery I'll be using (http://www.aliexpress.com/item/4P-1S-18650-8800mAh-3-7V-lithium-battery-pack-high-quality-product-for-emergency-light/32234115362.html)

Thanks

[Forgetful Jedi Knight]

I've ordered a bunch of saber parts for a LED strip blade (should be arriving in a couple of weeks) and I'm looking for a charger for my battery. I was just wondering, would it be possible to buy something like this (http://www.aliexpress.com/item/Dual-Smart-Battery-Charger-for-18650-Rechargeable-Li-Ion-3-6-3-7V-POWERFUL-BLACK/32242953037.html), cannibalise it, and wire it up to my battery pack?

This is the battery I'll be using (http://www.aliexpress.com/item/4P-1S-18650-8800mAh-3-7V-lithium-battery-pack-high-quality-product-for-emergency-light/32234115362.html)

Thanks

What parts did you buy? I'm asking because that battery pack likely won't fit into what you bought. I also am not sure why you are using that pack.

[Ursa]

It's pretty small, 18mm x 65mm. I haven't ordered any of the hilt parts yet, just put in a tentative enquiry about some 35mm brass pipe. Is there something wrong with that pack?

[Forgetful Jedi Knight]

Each one of the 4 cells in that pack is 18mm X 65mm, and they aren't THAT small.

[Ursa]

Oh wow, that's definitely way too big, 5.1cm diameter, thanks for the heads up.

If it's just 8 cells and a pcb soldered together in series then wrapped in plastic, do you think I could cut it open and rearrange them into a triangular prism (rather than a cuboid)? That should bring the diameter down to 36mm, which would just about fit inside what I have in mind. I was planning on making a long hilt anyway, just as well :)

[Forgetful Jedi Knight]

Why are you going with such a large battery pack anyway?

[Ursa]

I'm trying to make a LED ladder blade like makoto's ones (http://www.fx-sabers.com/forum/index.php?topic=13487.msg212271#msg212271). I figure it'll work out at ~200 leds drawing 20mA each, so the blade will run at 4A total. Hence the hefty battery.

[Forgetful Jedi Knight]

200 LEDs??

[Ursa]

Well sure, if it's a 1m blade, with two leds for every centimeter, then that works out as 200. That hampton guy packed them even closer by grinding off parts of the enclosure.

I think I have a space saving solution for the batteries: If I separate the cells out and arrange them in a zigzag pattern they should use the space more efficiently, doing a test with some paper now...

[Forgetful Jedi Knight]

Well sure, if it's a 1m blade, with two leds for every centimeter, then that works out as 200. That hampton guy packed them even closer by grinding off parts of the enclosure.

I think I have a space saving solution for the batteries: If I separate the cells out and arrange them in a zigzag pattern they should use the space more efficiently, doing a test with some paper now...

That Hampton guy... Oooohhh boy.

[Ursa]

Hmmmm?

[Forgetful Jedi Knight]

Hmmmm?

Let's just say I'm not a fan, and that isn't anyone I would EVER recommend emulating. But that is just my opinion as an established community elder.

[Ursa]

Ah right. I've never spoken to him personally, just seen a few of the threads he wrote.

I'll see what I can do with these batteries. I ordered a 4A buck to go with them, would it still work if I powered it with four cells rather than eight? I could just make them up into two separate packs and change them when one runs down.

[Forgetful Jedi Knight]

BuckPucks need over 5V to properly power them. You would have to check the specs.

[Ursa]

Thanks :)

[Daisan]

Hi Ursa,

Have you checked this thread (http://forums.thecustomsabershop.com/showthread.php?16889-My-first-LED-string-blade-a-progress-diary)? It is LED string and I think Obi1 only used ~84 LEDs.

Just from the pics, I think he has a space-friendly solution to battery/power question.

Cheers and good luck on your project! :)

[Ursa]

Hi Daisan,

I had as it happens, I've been lurking around for a while. Hadn't noticed the number of LEDs he used though, if it turns out to be less than I thought then that would definitely make powering it alot easier.

[Forgetful Jedi Knight]

Which is why I questioned the number of LEDs you planned join using (plus your blade length was really long). Generally speaking the number of LEDs is around 84 in a string blade.

[Ursa]

Well the first thing I'm building is the LED string, so I'll see how it goes. If it turns out to be less LEDs I certainly won't complain.

Back on topic, is canabalising the innards of one of those chargers a sensible thing to do for charging a battery pack? Or is that an excercise in stupidity?

[Forgetful Jedi Knight]

Well the first thing I'm building is the LED string, so I'll see how it goes. If it turns out to be less LEDs I certainly won't complain.

Back on topic, is canabalising the innards of one of those chargers a sensible thing to do for charging a battery pack? Or is that an excercise in stupidity?

An exercise in stupidity.

[Ursa]

Thanks.