We have a Noco Genius, 3500 I believe, shared between plane, cars and motorcycles. Comes in both EU and US voltages, the EU one at a significant premium to US versions when on sale.
This is weird.
Firstly, what is “aviation-specific”? I don’t think aircraft batteries are any different in their fundamentals to car batteries.
Secondly, it is daft to not make a wide input range (100-250V AC) product. The technology for doing that is trivial nowadays. All the chargers use the same switch-mode designs.
They say that aviation lead-acid batteries have more acid, and thus require lower voltage on charge, and are being overcharged by a standard charger. See https://www.batteryminders.com/why-an-aviation-specific-charger-maintainer/
Whether they are right, whether the effect is big enough to care, I don’t know first hand.
The Batteryminder units even use different voltages for different battery brand/models.
I use a ctek, on mine, and am happy with it, although I’ll probably only put it on once or twice a year.
Can these things be carried in checked baggage? In US now….
Yes; on holidays I often travel with a big multi output USB charger.