Yet another battery wiring
I have had installed a Balmar
SG-200 smartguage this weekend, which has prompted a few broader questions on my part. Current wiring
diagram attached (simplified).
The prior owner appears to have added a third house battery
at some point (Bat 3). I have just replaced all batteries
. Ideally they’d be next to each other but there is no way we can achieve that for now due to space constraints.
is on shorepower for 300 days per year. Boat
has a generator
. Most trips are (sadly!) only a night or two, with a 3-4x per year trips for 3-10 nights. We have what I would call moderate power demands – have gas hobs for cooking
, use inverter
for microwave (used infrequently), the toaster and the TV, but have a full sized DC fridge.
Grateful for any feedback. My main question is how are we best to wire in the port battery (no 3) given the distance from the other two. One thought was to run charger
+ve to Bat 3 so at least that port house battery is not ‘hanging off’ the main circuit. Someone also suggested an AC post with equal length leads to all batteries
. I ran a fairly crude test with what I had onboard in the weekend: All batteries fully charged and had inverter
pulling 160amps - Bat 3 showed 12.61v at the terminal and Bat 1 and Bat 2 both showing 12.55v at the terminal (which to my basic mind suggests that, as you’d expect, Bat 1 and 2 were doing the heavier lifting).
NB: I’ve left the existing Mastervolt shunt in because the display in the salon
provides some useful data.
Thanks in advance