How to wire batteries? - Alternate method?

[Tintin]

I have always assumed that the correct way to wire up the batteries (aux and engine bank with a VSR/ VSS ) would be something like this.....

View attachment 40331

And then reading a book on boat electrics (Boat owners illustrated electrical handbook, Charlie Wing), I came across this alternate method which seems to ensure that at no time can a load be unswitched from the alternator, thus protecting it.

View attachment 40332

I am tempted by this as the basic schematic - any thoughts or issues anyone can see?


thanks
CR

 

[nigelmercier]

I did mine the second way. Less current to switch, hard wired to domestics.

 

[BabaYaga]

My batteries are also wired as in no 2, but consider the position of the fuses.
In the sketch, both the the starter wire and the alternator wire are unprotected.

 

[Sarnia]

I have always assumed that the correct way to wire up the batteries (aux and engine bank with a VSR/ VSS ) would be something like this.....

View attachment 40331

And then reading a book on boat electrics (Boat owners illustrated electrical handbook, Charlie Wing), I came across this alternate method which seems to ensure that at no time can a load be unswitched from the alternator, thus protecting it.

View attachment 40332

I am tempted by this as the basic schematic - any thoughts or issues anyone can see?


thanks
CR

In addition there are preferred methods of connecting batteries together in banks, I found this very informative, hope others do to.

http://www.smartgauge.co.uk/batt_con.html

 

[TradewindSailor]

I also have a system close to 2. With a large house bank (750 Ahr) it is the best way. Obviously the cables should be fused close to the battery.

The first arrangement is typical of standard Yanmar arrangements ...... which to my mind is shortsighted : the alternator is usually internally regulated as standard, so it relies on local voltage to regulate the charge. The additional connection at the started is likely to introduce an additional voltage drop, especially if it get corroded ..... and hence none of the batteries get a good charge. At least with the second arrangement the house bank ..... usually the largest and most expensive bank ... is prioritised.