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Can I use a small 12V A23 battery to power this negative ion generator? Will it burn or will it last for long?

Edenia
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1 Answers1

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Will it burn or will it last for long?

Probably neither, look at the Wikipedia page on the 12 V A23 battery. Note how this battery consists of many small coin cells in series.

Coin cells cannot deliver much current, they're quite small.

5 W at 12 V that's 12 / 5 = 416 mA, that's too much for almost any coin cell.

Scroll down on the Wikipedia page, under the external links there is a link to an Energizer A23 battery. Note how the Capacity is shown for discharge currents of 2 to 15 mA. Hmm, that's around 30 times less current than what you would need for 5 W.

There's also a thing called internal resistance. This internal resistance is related to the size of a battery, small batteries have high internal resistance and that means they cannot deliver a high current.

Conclusion: A23 batteries simply aren't suitable to deliver 5 W. You should use eight AA cells in series instead, they can easily manage 416 mA.

Bimpelrekkie
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  • Very good answer. I have x4 hi-drain LG Li-ion cells each 3.7V 20A, but they are really hard to connect, I am afraid I don't have the resources to connect them and they also take a lot of space. So I was looking for the smallest battery that can power this thing. – Edenia Jul 01 '18 at 15:38
  • If you're tight on space and 8 AAs are too big, you may use 8 AAA cells. They can handle 416 mA, even though it's a bit of a stretch (and they'll only last two hours tops at that current). The 8 AAs is a more robust design. – anrieff Jul 01 '18 at 16:13
  • @anrieff 8 AAA cells is quite expensive, especially if they are rechargeable. Since I have xtar charger, I probably want them to be rechargeable. The best option I can think of is using 3 li-ions, but they make up total of 11.1V. The other option is 4 li-ions (14.8), but I will need to soldier a resistor, and soldiering resistor is quite a bit of work. We don't have spot welder even with one electrode. Connecting them will already be a challenge, let alone with a resistor. Maybe Lithium 29A 9V battery? – Edenia Jul 02 '18 at 11:52
  • I can't imagine something with that size to be able to contain that much current. – Edenia Jul 02 '18 at 11:59
  • How are 8 AAA cells expensive, considering that in a lot of places you can get them at less than $0.25/pc if you buy them in bulk? Yes, rechargeables cost more, but then it's a one-off thing and it's still a < $10 investment. If it's just an one-off installment, I wouldn't worry about the price. – anrieff Jul 02 '18 at 15:44
  • @anrieff I am from Bulgaria. Here prices are different :) – Edenia Jul 02 '18 at 15:57
  • Cool, I'm also from Bulgaria. Prices aren't that different, as you can see [here](http://anrieff.net/batterytest). You can sort cells by price so you can choose the best value for the price. – anrieff Jul 02 '18 at 16:09
  • Very cool project, I can help with borrowing you LG HG2 batteries. They are unused. I will check the list carefully, but what do you think about Li-ion LIR2450 3.6V 110mAh? They are quite small, each is about 110mAh, is rechargeable and is 3.6V – Edenia Jul 02 '18 at 19:55
  • @anrieff or even better: the rechargeable duracell DL2032 180mAh 3.0V coin cell. – Edenia Jul 02 '18 at 20:41
  • I would need like 8 though. 4 in series and 4 in parallel. – Edenia Jul 02 '18 at 20:42
  • If you're tight on space for the batteries I think the best option is to ask a question specifically about that (12V/5W voltage source in minimum space). I guess a design with a single high-density Li-Ion cell and step-up circuitry might be the best one, something similar to what's used in e-cigarettes. – anrieff Jul 03 '18 at 23:07