Battery banks circuits

[Grehan]

Thanks for the useful guidance I got from my previous question http://www.ybw.com/forums/showthread.php?t=269487
Moving on from that I've now got the two 250Ah batteries installed (all battery link cables are very heavy duty) and they're working fine, so far as I can tell. I am, however, not sure that they way everything is wired up is exactly how it should be, so I'd be grateful if you vital sparkies would take a look at the following circuit diagram (I hope it's clear) and comment.

Key
C - 110Ah cranking batteries for starter and bow thruster
D1 - 110Ah domestic batteries (existing, before addition of D2)
D2 - 250Ah domestic batteries (aft)
SW1 - key type isolation switch, starter+bow thruster
SW2 - isolation switch, separates D1 and D2 (to allow Alternator Isolator to detect and charge separately when engine is running)
ISOL - Studer MBI 100/3IG 100Ah 3 feed isolator
ALT - Prestolite 14v 110Ah alternator
STR - starter motor
CHGR - battery charger
INV - inverter
I don't doubt it could be improved with some electronic gizmos, at a cost, but right now I'd just like any general comments on what's there, or suggested simple improvements, especially from the point of view of engine or battery charger charging. Thanks.

 

[Pete7]

I think you could improve the balance of the D1 and D2 batteries. Have a read of this:

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

Pete

 

[Stu Jackson]

It appears your domestic loads will always be on from D1. Consider making D1 and D2 into a larger single bank.

 

[Dave_Seager]

You do not appear to have any means of isolating the two banks of domestic batteries from their respective loads. Although the starter/bow thruster battery can be switched off it would still be connected to the alternator isolator. If you have a short circuit in the inverter or a domestic circuit you would be in trouble.

I assume that there are fuses in the system that you have not show here.

 

[Stu Jackson]

A link for you to review, that includes a very good discussion of systems as well as wiring diagrams and links to other wiring diagrams

http://www.sailnet.com/forums/electrical-systems/70350-battery-bank-design-recommendations.html

 

[BAtoo]

My 2p.

Your domestic bank should be batteries of equal size (Ah) and type and preferably make.

Your Alternator should charge these equally preferably via a Voltage Sensitive Relay (VSR) which ensures your engine battery is fully charged first.

It looks from your diagram that the domestic output is running off the D1 bank and not the combined D1/D2 banks.

It looks like your inverter is only off D2