Where to put battery charger for 2016 243VRX?

[MGrande305]

2016 243VRX here w/Twin 250s. Where is a good place to mount a battery charger? .I just started shopping for a battery charger, and trying to find a place in the engine compartment for it. I was thinking on the horizontal sill just above the starboard heat exchanger where the starboard battery sits (See photo). I just today measured what looks like I may have about 12" x14" of "lay flat" space there to work with or so (some of that space being under one of the hoses, so it may touch that a bit). Plus there are some screws in that sill already for some hose clamps, so that tells me it's cool to put screws in it. If that location won't work, then I was also thinking maybe under the port or starboard flip-up aft seats, but I think the ballast bags will be an issue when full. Also in terms of the battery charger itself, I was thinking getting the "Noco genius genpro 10x2 20 amp 2 bank charger. Is 20 amps overkill for running the music system all day at the marina without running the engine?(with the battery charger plugged into dock power). Thanks in Advance.