[cctalk] Replacing NiCd with NiMH in a pro way.

Hey everyone, No - I won't ask if this is on topic or not :) I'm currently reparing an ALPS plotter ( a Tandy "ce 150" equivalent ) and it's not the first time I face the same problem ; how to replace NiCD batteries. In the past what I did is actually order new NiCd ( you can still find them here in Europe, well actually out of europe but in eastern countries close to europe ) However they are at best NOS nowadays, that does "work" enough for moderate use (I've done that on vintage laptops) This time I'd like to go a bit beyond that and replace the NiCd with modern NiMH (the plotter coils and motors will benefit the extra power) However the trickle chagre of NiCd applied to NiMH will either kill my batteries or kill me in a house fire. I see small $1 NiMH 5S charging boards on Aliexpress, I thought I might use that, try to shove it it the CE150 (or other devcies with the same problem) TL-DR : Before I re invent the wheel here ; Has anyone developed a proper way to replace NiCd with N iMH in vintage (mostly portable) equipment ? And I mean not simply swapping the batteries, I don't want that, I want a proper charge process.