Battery Switch Replacement - ACR?

[Timccarpenter]

I've got a simple battery system for our 27' Tartan sailboat. Two 24 group deep cycle batteries and the old style OFF - 1 - Both - 2 Switch. I've realized recently that our one battery is not getting any charge from the Alternator when the engine is running. It seems to be the switch that is faulty. I checked and cleaned the connections on the cable and the continuity checked out fine. The switch is at least 20 years old.

I'm looking at replacing the switch but am finding, in addition to the traditional old switches, those that are simply 'ON' and 'ALL' with an Automatic Charging Relay (ACR). It seems these setups help prevent issues with draining batteries by not switching to 1 or 2 under sail after shutting off the engine. However, does it have limitations? What if your starting battery fails and you need to start with the house battery? Does switching to 'ALL' really work or does that bad battery draw down the good one?

Simplest solution is to replace the switch as is. However, I don't want to make a mistake by improving the setup if there is a significant advantage.

I appreciate the input/guidance

[Wotname]

A 'OFF - 1 - Both - 2 Switch' is fool proof as long as the operator is not a fool. Most of us (including me) becomes foolish occasionally and when that happens, a 'OFF - 1 - Both - 2 Switch' is not ideal.

An ACR is fool proof as long as the electronic 'brain' works. An ACR has a manual override function that you use when you wish to parallel the batteries.

I used to prefer the 'OFF - 1 - Both - 2' switch, now I prefer an ACR.

Alternator to Start Battery, ACR between Start and House Battery.

Start battery is always fully charged (100% SOC) without any input from you. House battery SOC varies up and down with use. If Start battery fails, use the manual override function of the ACR to parallel Start and House.