2 Engines, 2 Start Batteries in Parallel, 2 Alternators

[darren.m]

Hi. Im just reconfiguring my setup. I have two diesel engines and 2 start batteries. They are wired to a 1, 2 or both Guest selector switch so I can start either engine on start battery 1, 2 or both. It is / was my intention to select the engine batteries on an alternative basis of say one month intervals. I also have 1 leisure battery wired to another Guest 1, 2 or both selector. In this case my option is 1 or off as there is only 1 leisure battery. Im also going to install a Merlin Smartbank Advance and Smartguage. This will monitor both engine start batteries, either 1, 2 or both and the leisure battery. There will also be the option to emergency connect the leisure battery in parallel to the engine start batteries should both engine start batteries be discharged for whatever reason. Triple backup!!.

My question is, having two engines, each with their own alternator feeding back to charge either engine start battery 1, 2 or both, is this ok. Thanks.

 

[BruceK]

Roy had a complicated setup like that, first long trip out with us he flattenned and killed all his batteries because the switching was too complex, he got it wrong but the beer was cold. He's a mate that way. I have it easy. One chunky starter battery for both engines. One engine alternator does starter, the other engine leisure batteries, a solenoid shunt from the helm to connect the two in emergency and solar panels to keep it all in top shape. No messing about with switches that will oneday catch you out.

 

[kashurst]

Have a look at this:
Battery Mate 1602 IG | Mastervolt

you connect both alternator outputs and your battery charger to one connection, then each of your battery banks to a separate terminal for charging. Makes it all really easy.