Still very happy using this small and lightweight charger
For less than 10 Euros, I didn't bother making one myself.
It is slow (Imax is 1.5A), but as Andy says ... maybe better for the battery life.
I charge a commercial LiPo 5800mAh pack with it, as well as several homebrew Li-Ion packs via the balancing wires (I have 2S 3S and 4S packs in use, and not just for SOTA, e.g. my bike lights are also powered from a 2S Li-Ion pack hi)
And it works on 12V in the car too, so I can charge while driving from one summit to another.
Luc - ON7DQ
(edit) : this was the latest pack I made, 4S2P, 20A car fuse built in, made from Dell laptop cells, estimated capacity 4800 mAh. It served all my operating with the KX3 at 15W (using the automatic voltage reducer) on 17 summits in EA6, and all 22 summits on my recent FH trip, easily doing 4 summits in one day without recharging.