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Q & A: What battery is needed?

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Most recent answer: 04/14/2015
I need the correct battery to power a 20 Watt, 12 Volt 2 pin Halogen bulb for several hours (5 to 8).
- Joe (age 59)
Punta Gorda, Florida, usa

Your 20 W bulb will draw 20/12= 1.67 amps of current. If you want that to last up to 8 hours, you need a capacity of 8*1.67 or about 13 Ah (that's amp-hours).  Pretty much any car battery would do, or a large motorcycle battery. The battery specifications will give the Ah capacity.

 But the halogen lamp is not optimal. You can do yourself (and the environment) a favor and use an LED bulb instead, for longer life with a smaller battery. See posts here () for details.

Tunc +mw

(published on 04/14/2015)

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