B40 Charger Alarm Behind Saloon Berth

[B40-Lefkas]

Can anyone help me identify the purpose of the two boxes with A/V meters that sit behind the saloon berth in my 2008 B40?

The orange charger is separate and as far as I can see self-contained. The alarms sometimes go off on on the one box as shown in the photo. I've had this happen on several  charter Bavarias and they always said to turn off the RCD style switch on the box and leave it off.

Anywhere I could get a full wiring diagram for the boat?

Many thanks in advance!!

[Symphony]

It is what it says it is - a DC/DC battery charger. Purpose is to charge the back up battery for your radio. Often a statutory requirement for charter boats.

[Lyra]

As Symphony indicated this is a battery to battery charger.
On Greek charter boats they have another (3rd) mandatory battery only for the VHF (and GPS I if memory serves me right) - the input is from the house battery and the output is to this dedicated battery. This way even if the house battery gets depleted the 3rd battery remains charged since it is totally isolated from the boat circuit.
If your boat is ex charter then maybe the 3rd battery has  been removed and this charger has no purpose now.
You would not see this in any Bavaria wiring diagram since this is a local installation.
In my boat I dismantled it and connected the VHF to its own circuit on the panel (one of the spare circuits)

[B40-Lefkas]

Many thanks! Makes sense as the boat is ex-charter (and new to me). This boat has two radios and two independent batteries, in addition to the starter and house bank. Complete overkill as I also have a handheld and an EPIRB. I think I'll pull the whole lot out and run it off the panel as you suggest.

[Symphony]

Yes, that is what I did when I stopped chartering my boat. Made room in the battery box to fitr larger house batteries. Just sold the charger in the Yacht club auction for a few £s. This solution to meeting an independent supply for the radio and gps seems to be a Greek thing. In the UK it is more common to have a third battery charged direct from the alternator through a diode to meet coding requirements.