car battery

[adeadlyfart]

has anybody used a small car battery to power a spotlight? just curious

 

[Lynx_Arc]

I am sure people have used all sorts of 12v cells to power spotlights... including motorcycle batteries and deep cycle marine batteries which are probably more suited for spotlight use.

 

[jbev]

You can use a car battery, but as Lynx suggested you would be better off with a different kind. Every time I'm on trips in S.A. I see people using car batteries for that. They put one in the front of the boat for their crummy little spot lights. Every time I'm down there I feel I should explain that they should be using a gel cell/deep cycle battery. The only reason they use them is the cost. i.e. cheap.

 

[Lynx_Arc]

People commonly associate CCA (cold cranking amps) with runtime on batteries and deep cycle marine batteries don't have as high of CCA as conventional car batteries but they have considerably more Ampere Hours which essentially is like comparing peak output to continuous output. The more Ampere Hours the battery is rated for the longer runtime you can expect from it and if AH is barely adequate, larger AH batteries can actually improve brightness also till they are discharged down to where the smaller AH batteries *sag* to under a load.

 

[Draco_Americanus]

Also too, unlike a deep cycle battery, a car battery would be easer to damage by dischargeing to too far. A car battery is not made for cyclic use as would be experanced in a spot light and would have fewer charge/discharge cycles before the battery whent bad.