That's too much of a gadget for me. ie special purpose, not useful for other purposes.
When to you want to use the cooling, just in the evenings before bed for a couple of hours?
Do you have a 12V compressor fridge/freezer? Maybe buy a spare and use the daytime solar to freeze/chill ice packs? Then flip up the cover and add a fan/duct to blow the air over the packs to where you want? See the 5 gallon ice bucket air conditioning videos on the internet. This won't cool for much, maybe just a few hours.
You could prototype this and see how it works with your current DC freezer. If it works, buy a second freezer/fridge. Worst comes to worst, you have a spare freezer if yours dies.
a 12,000 BTU air conditioner is a "one ton" A/C. It is equivalent to the energy released by melting one ton of ice into water. That phase change is the most energy you get out of water.
2,500 BTU is about 5 times smaller than 1 ton. 1 ton of ice is 2000 lbs of water, so 2,500 BTU is equivalent to melting about 400 lbs of ice over 24 hours.
Engel's 84 Quart DC compressor freezer is 21 gallons. 21 gallons is about 168 lbs, which could be 2500 BTU for about 10 hours. or maybe 5000 BTU for about 5 hours.
things to consider...
You would need to put bottles in the freezer so you won't get that many gallons into it.
You will not freeze 168 lbs of ice with a DC freezer in 24 hours. It would take days.
You can shift your demand/supply for power with the freezer. Solar is not constant. You could want to run the AC, but the sun isn't charging. Ice storage can shift the supply/demand timing.
If you don't get enough solar, you can buy ice at any convenience store for emergencies.
I haven't done this. After you buy the Engel and it doesn't work, you can sell it to many other people used. I'll take if for free. Your chinese A/C would be flammable hazardous trash as I can't see many others taking it.