I've been trying to reach out to DeWalt, but their contact page isn't working for me—every time I submit, the page just reloads! So, I'm asking here: what's the biggest battery that can be used with the tripod light? Can it handle one of those hefty 12Ah batteries?
3 Answers
The 12Ah is definitely the max size that is compatible. A 15Ah won't fit due to intentional design. They're keeping it limited for some reason.
I've used my 9Ah Flexvolt battery, and it fits perfectly—it's a really big battery. Just a heads up, the 12Ah is the maximum that will fit, nothing larger like the 15Ah is designed to work with it.
You can fit either a 9Ah or a 12Ah battery on that tripod light since they are the same size. I haven't tried fitting a 15Ah, though, so I can't help there.

I wonder why they did that?