I also use the X65 battery pack in the K75. You can buy the X65 battery pack on Ebay or BHPhotovideo. The charger is an ASUS 19V 3.42A 5.5mm plug that you can buy from Ebay.
As I have a lot of 30Q batteries,flat and button top,I decided to buy one without the dedicated Acebeam ones because I saved about €40.00 .Will the K75 work properly with them?
Sorry for late reply, I missed your post.I saw your vote for R90TS in the best of 2019 topic, so I decided to search your posts to see what else we agree on, and there was you question for me. < embarrassed>
It is strange that no one complained about the very short turbo run time in Power mode. After a few seconds, the lumens are reduced to less than half and certainly also the throw. The two Power and Eco modes are misleading. Practically the behavior of their turbo levels is the same! Just look at the reviewer's chart.
Much better is the behavior of the most recent BLF GT-90, with the same LED, whose turbo lasts at least 15 mins. and the performances are even higher than the K75. Look at the video review: https://www.youtube.com/watch?v=xQBDrNKyWKY
Today,I put a new set of Sony high drain batteries,putting the 30Qs already used,in a Astrolux MF04.After that,I checked the beams of the two lights,and I saw that in strobe mode,the MF04 is way better than the K75.For defence I mean.