2016 Yamaha 242 Limited S Audio Upgrade

[Dalesy]

I've had a local audio installer add 2 -800 watt arc amps, 2 - 12" wet sounds subs and 2 - 6" kicker tower speakers. Wish I would have spent the $$ and wet with bigger wet sounds tower speakers but that can be next on the list.
Question i have is that I've heard good things about the NOCO Genius 2 bank on board charger so purchased and installed this evening. The plan is for it to recharge 2 - Kinetik HC3800 power cells that are responsible for providing power to audio. I hooked each set of leads to each Kinetik battery (batteries connected in parallel) for audio and once plugged in get a nasty humming noise from the speakers. It doesn't sound normal to me. Any ideas on what i am doing wrong??
PS - Original batteries for start and house still on board and are running what they were designed for.

 

[Julian]

Do you have a common ground busbar, or ground wire connecting all the batteries? If not that could be your issue....

 

[Mainah]

Two batteries connected in parallel is one bank not two. Only use a single bank charger for that setup or pull the fuse from one of the leads from the current set up to turn it into a single bank. Those “power cells” are really giant agm batteries but about 35% bigger than group 31 agms and designed for higher amp loads. They will take awhile to charge as a single bank but have plently of instant amps once charged.