The Imax B6 is probably the single most cloned/repackaged/added on to charger out there today. Drone guys use it, RC car guys use it, RC Airplane and heli guys use it......... I have two clones that I use for my RC hobbies and they've been active for over 10 years with zero issues.
Some of the clones are more reliable than others. "Comes with a power supply" can be a good thing or a bad thing. All you really need for rocketry charging and to power the chargers is the ability to make 12vDC at 1 or 2 amps, but RC guys like 10amp or better for larger packs. A simple wall wart is usually ok for rocketry, but for $10 or less you can get a corded box power supply like most laptops use that'll source 10 amps.
I have a converted blade server power supply that I use as a bench power supply (12vDC at
47 amps capacity), and for the field I have a modified cigarette lighter adapter so that I can charge at the launch, if necessary.....and I've never found it necessary!
Some guys alligator clip to their car battery terminals.
Ultimately you're also probably going to want extender harnesses for charging your various batteries. You'll want ones that match your battery outputs as well as a 2S extender or a 'balance board'.
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