35 watt HID running off 12v deep cycle with no alternator

[snimmer]

Hello everyone,
I searched the threads for this topic so if I missed it, my apologies and please direct me to the thread if you know its location. I am rennovating a golf cart and I'm adding a stand alone 12v deep cycle battery for accessories (stereo, head lights, led dome lighting, roof fan, and 12v cig plug outlet). My main question is will a stand alone battery with no onboard alternator successfully power a pair 35 watt HID lights. My main question is not necessarily in regards to runtime, but moreso the potential problems of a decreasing voltage as the battery is discharged.....in other words, at what state of discharge (or voltage drop) might I expect to experience difficulties with powering the HID headlights and keeping them lit. I realize the aformentioned accessories will play a role in this question or at least add to the equation so far as the speed of battery discharge and the battery's ability to provide enough amperage for the HIDs, but lets assume minimum use of the accessories or perhaps consider the 1.5-1.7 amps that my head unit draws when playing the stereo. I am really wanting to find out if the 35w HIDs are going to be more aggravating than they are worth.....or would I be better off putting together a couple of LED lights and constructing a way to run them off of 12v?

 

[BVH]

Many ballasts I've tested run ok down to 10 Volts plus or minus. You'd damage your battery if you repeatedly ran it down that low so as long as you regularly recharge it when you reach 50 or 60% Depth of Discharge (DOC), the HID's will most likely work fine. You'd want to get a deep cycle battery for your specific type of use and for longest life, run it down to about 40% DOC.

A good battery DOC table near the bottom of the page: http://www.solar-electric.com/deep-cycle-battery-faq.html

 

[snimmer]

I dont plan on running the 12v accessory battery or the 48v battery pack for the powertrain below 65% for battery longevity......so sounds like the HIDs will do just fine....thanks so much for answering my question BVH.

(teaching my girlfriend to remember this, understand the reasoning behind it, and getting her to remember to look at the two led meters on the dash for the 48v drive pack and the 12 volt accessory battery is an entirely different concern.....is there a forum teaching a girlfriend to do that?) :devil: Thanks again.