Best Battery for Lights-Noone Freakout!

I really like my odyssey extreme. Expensive but great starting power and good for accessories

 

If you can, try to measure the voltage to the gas gauge with your LEDs on and off. I suspect that gas gauge is dropping because of low voltage because of the increased current on the same circuit. If that is the case, try wiring the LEDs through a relay and fuse to your battery and contact the coil of the relay to your light switch. Size the wire to the LEDs based on the current, temperature and distance. There are several DC wiring calculators available on the Internet.