I no longer have the FT-817 as it went back to the owner shortly after my last post here, but I have been using the packs with my FT-290Rii with the 25w amp for contesting on 2m. I can run a whole 2.5 hour ssb contest on 1 pack and only use about 1/2 of the capacity of one of the packs. Really pleased with them.
I've also built myself a 3S3P LiPo 6.6Ah pack from recycled 18650 cells and the Vruzend end caps. I use this with my uBITX /P as I prefer to run the uBITX at a nominal 12v rather than 13.8v. I also have a 3S1P pack made from the same batch cells that I use to run my USB devices such as the R-Pi, via 12V-USB Buck converter.
I've also built myself a 3S3P LiPo 6.6Ah pack from recycled 18650 cells and the Vruzend end caps. I use this with my uBITX /P as I prefer to run the uBITX at a nominal 12v rather than 13.8v. I also have a 3S1P pack made from the same batch cells that I use to run my USB devices such as the R-Pi, via 12V-USB Buck converter.