The Siren Board

I’m trying to replicate a DC siren charging and contactor circuit. I’m fairly certain I came up with something that will function, but I’m hoping the experts might be able to chime in? Correct me if I am wrong with any of this. This will run a T-128. Basically I’m under the impression ASC separates the charging circuit from the run circuit via 4 relays controlled by the contactor circuit. When the contactor closes, the relays switch to a N/O position. As far as charging, I saw the 12V chargers are wired in series, therefore producing 12V, 24V, 36V, and 48V. Not sure if these are run of the mill chargers, or special ones. I know they just plug into a power strip in the control box so I’m assuming not the latter. ASC only specifies “Charger, 3A @ 12V, 2 Stage, Potted, Guest.” Threw in the fuses ASC specifies on the logic board diagram. Here’s what I have:

And the chargers wired in series

For charging, your best bet it to get a couple of marine battery chargers with multiple outputs. Just connect the leads to the individual batteries and you're done, no relays required. Here are a couple of examples. For 4x12v batteries, two of the two bank models would be best.

https://www.westmarine.com/buy/guest--c ... ecordNum=6

https://www.westmarine.com/buy/promarin ... cordNum=24