I have a pump for my misting system:


The pump is 12V DC - it's powered by a AC-to-DC power adapter:

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Unfortunately, I'm trying to use it on my balcony, which has no AC powerpoint.

What are my options for powering this without a mains supply?

Would connecting a 12V car-battery work? Or is there perhaps something a bit more turn-key that could work?

Update: To clarify, the reason I can't run an extension cord is because there are two glass doors between the interior and the balcony, and we need to keep them shut often for various reason (air-conditioning, because of our cat, in case of rain, and also if we go away). There is a lighing socket out there - so a lighting socket to power socket adapter might be an option.

I suppose I could hire an electrician to install a new outlet out there. (I can't think of a way to punch a extension lead out there that's waterproof or wouldn't let water back into the house)

  • 1
    \$\begingroup\$ Sure a car battery is 12 V DC so that should work. But at 4 A, average car battery of 40 Ah, after 10 hours the battery is empty. Will you carry it inside to charge ? Do you have a charger ? Turn key solution: a petrol generator perhaps. But these are noisy, smelly and require petrol. Why not simply use a mains extension cord ? \$\endgroup\$ – Bimpelrekkie Sep 5 '17 at 14:44

Two simple solutions. One. If your balcony has a light bulb socket, use a socket to outlet adapter.

The second requires running power. At 48W, you could use a higher voltage DC supply, like 48V 1.5 Amps (to make up for power loss) and use a local dc to dc step down converter. Just get the right gauge cable for the round trip distance with minimal power loss. At this point, you are essentially just using an extension cord with additionally circuitry. A regular extension cord would be easier.


The important point here is how much power will it draw. Your adapter is rated at 5 amps of output current. Given that a cheaper car battery holds around 45 amp-hours of charge, you'll most likely be able to power your pump for 7 hours from it.

So the question for you becomes - how often will you use the pump? If you intend to use it every day for an hour, you'll get around a week of runtime. After that, you'll need to charge it again, which also costs money because you can't just plug a battery into the grid and wait - you'll need a charger that will make sure you don't overcharge your battery, at the very least.

If you use the pump rarely, it makes even less sense to invest in a battery like that.

I would suggest getting an extension cord (a good one that will be able to properly work in the mist) and routing it carefully to your balcony. This will cost much less than just using the battery.


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