Powering 12V LED strip lights with a 12V deep cycle battery
Can you reconnect strips in series 12+12=24V, then you can use boost dc-dc converter from your battery around 12V to stable 24V?
This arrangement will give you stable light that is not dimming during battery discharge. That's what I did with my emergency light - there is 6 strips with 3 LED each. I connected three of them in parallel (12V), connected other three in parallel(12V), and connected those 2 pairs in series which gives 24V. Then I bought this boost converter (about 3 USD) and it still works perfectly.