Battery Question(s)

[korovyov]

Hi all,

I'm in the process of building a sculpture which is in essence a very simple battery-operated lamp, using LEDs hooked up in parallel (each with a resistor). I'm trying to figure out the most appropriate solution for powering it, and am pretty sure that I want to use one Li-ion cell (3.7-4.2 V) as it seems the closest easily obtainable voltage source to my needs (~3.3Vf).

My assumption had been that I should buy an 18650 battery and an appropriately sized battery holder with leads, but I then got to thinking perhaps it would be more compact and economical to use an aftermarket proprietary battery pack (eg for a digital camera) running at the same voltage.

My question is, is there anything in those battery packs that would prevent them being used to power other things? Also, I would assume that they're always protected cells, but of course the specs aren't readily available. Anyone able to shed any light?

Thanks so much!

Jared Friedman

 

[CocaCola]

Nothing on those battery packs will prevent them from working...

Cell phone flat pack batteries can be had for dirt cheap, and so can external universal chargers... But hooking them up to your light can be a little hassle...

If you want easy get some 14650 instead of the 18650, they will fit in 'most' AA batter holders, so you can easily source a holder... Be aware if you want to run two of the 14650 to get double run time you will need to modify the over the counter two AA holder from series to parallel...

Both the 14650 and a charger can be had very reasonable on Ebay, make note of the charger, some require you to put two batteries in at a time to charge, thus if you want to always have charged batteries on hand you will need 4 batteries so you can swap them out in pairs...

 

[korovyov]

Thanks so much! That gives me a world of more options. Duly noted on the 14650s, may well use those too.

 

[HellasTechn]

Hi all,

I'm in the process of building a sculpture which is in essence a very simple battery-operated lamp, using LEDs hooked up in parallel (each with a resistor). I'm trying to figure out the most appropriate solution for powering it, and am pretty sure that I want to use one Li-ion cell (3.7-4.2 V) as it seems the closest easily obtainable voltage source to my needs (~3.3Vf).

My assumption had been that I should buy an 18650 battery and an appropriately sized battery holder with leads, but I then got to thinking perhaps it would be more compact and economical to use an aftermarket proprietary battery pack (eg for a digital camera) running at the same voltage.

My question is, is there anything in those battery packs that would prevent them being used to power other things? Also, I would assume that they're always protected cells, but of course the specs aren't readily available. Anyone able to shed any light?

Thanks so much!

Jared Friedman

18650 are high power batterys and can deliver several amps for quite some time. In your project they may be a bit large but they will keep your LED lit "for ever"

There are other 3.7 volt batterys that are same size as normal AA batterys. they are not expensive and can use same charger as 18650 batterys.

(18650 batterys you can find inside laptop batterys if you break them open). Also the laptop 18650 arent protected because the battery pack has an integrated control circuit.