The thing with air conditioners is that they are becoming more and more efficient. A kenwood AC we installed last year is more than twice as efficient as a Mitsubishi AC we have had since 2005. On paper and in practice. I think that it is always smart to upgrade your ACs after every decade or so.

If you are on a budget, I highly recommend the Xiaomi 20000 mAh power bank. It is a lot cheaper than Anker products and it works like a dream. It supports fast charging, and itself charges really fast. I have been using mine for around 2 years ( I never plug my phone directly to a wall socket) and despite that heavy use there hasn't been any change in performance.