The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.
Looked in the manual and searched here, but couldn't quite find what I was looking for.
Boat came with a second battery installed, but when I bought it, it was winterized and the batteries were disconnected. I've re-installed the batteries, but want to make sure I'm hooking everything up correctly. The photo mocks up how I believe the wiring should be attached, based on cable lengths and the fact that the marina wire tied things together:
Essentially, one red wire to each battery positive post, with the small fused red wire to the bottom battery positive. Negatives are connected together, with the two small black wires to the top battery negative post, and the lead to the bottom battery negative post.
On another note, for some reason the boat has two 1/2/off switches installed, seemingly in series. Does anyone know why that might have been done?
Adam, Can we reasonably assume that battery 1 and 2 have the negative terminals in common, battery 1’s positive terminal goes to battery switch 1’s terminal #1, battery 2’s positive terminal goes to battery switch 1’s terminal 2, and you don’t know why there’s a battery switch 2? Nobody except the previous owner knows why there are two battery switches however you can bet that if the guy spent $$$ on it, found a spot for it, took the time to install it — you know that there must’ve been a perfectly good reason for it. Perhaps to isolate the engine from the batteries, perhaps to prevent lightning striking or perhaps there was some parasitic current drain, but it’s there for a reason. The trick is now you have to figure out the puzzle. OR you can just take out the whole mess and start fresh. Rewire the batteries and panel according to the original Catalina specs.
I've asked him, he's not sure either. He didn't install it, that was the previous previous owner, and always had the marina winterize the boat. I'm going to try reaching out to them. I had wanted them to de-winterize it before it was shipped, but that didn't make it onto the WO.
To me, it looks like this setup, I just need to trace the small gauge wires to see where they feed since I don't have an automatic bilge pump:
The two positive feeds go to the first 1/2/off switch (starboard settee). From there, there is a positive feed to the motor, and two large gauge wires go to the second 1/2/off switch (sink bulkhead). This then feeds the master panel.
The heavy gauge negative wire feeds the motor directly.
one small gauge black wire goes to the negative bus on the sink bulkhead. The other one and the fused small gauge positive wire feed the "cigarette lighter."
OK, so basically the first battery switch is connected to the engine with a heavy gauge wire. Is this like #8AWG or #6AWG or #4AWG? This presumably provides starting current to your electric start engine and charging current back from the engine’s alternator to charge up battery 1, battery 2 or both batteries. The second switch appears to supply the house electrical needs like lights, radio, utility outlets, bilge pumps and running lights. The panel’s connection is a somewhat lighter gauge wire, perhaps #12AWG, #10AWG or #8AWG. You’d be surprised how much power 12VDC applications take, for example a 25W bow + stern light can pull a total of 4A. A 25W VHF radio can take 2.5A. Bilge pumps can take 3A. Therefore 12VDC wiring has to be thick, expensive and protected by properly sized fuses. Don Casey provides wire gauge sizing rules and guidelines in his book “Sailboat Electrics” which is also a part of his classic Sailboat Repair series.
Notice: The advice given on this site is based upon individual or quoted experience, yours may differ. The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.