[HanaShiratori]

I'm sorry I don't really get what you're saying. You can charge any (supported) battery type in any of those slots regardless of how many you want to charge at the same time. I can charge 4 eneloops simultaneously or 18650 or whatever...

[Fnoord]

Thanks, also jacquesm, I get/see it now. Its springs which adapt to the battery size. Neat!

[jacquesm]

Yes, most of these have that feature, what's unique about the MC3000 is that it allows you to create your own charge profiles ('programs') which you can then use to perform various operations on single batteries of batches of them. For instance, you can move batteries to a target voltage, which is wise to do before welding a pack with parallel cells (unless you like sparks, and if the difference is large enough, burning up interconnects).