So long as you follow the specs then it'll be fine.
But then I'd question are you keeping the transformer onto the string of LEDs or not. Essentially a transformer is used to safely convert the house voltage of 120V into the string to a lower current so that you don't end up burning it out.
All you really need is a battery and a switch. If you're not sure on the level of voltage you need start with a 9V and go up until it turns on. But if your transformer converts 24V then supposedly that's the voltage you'll need to go too.
But if you remove the transformer then some minor math and wire configuration is going to be needed to determine the level of voltage you're going to need to turn it on.
Of course this is just my thoughts as I suggest getting a second opinion on my diagnostics of the problem.
I hope this helped.
When in doubt, just take the next small step.
With that next step take a deep breath. It calms the mind.
When the mind is calm you realize the best is still yet to come.