I'm lost on this

Help...I have no idea how to get started so here goes.We bough our boat and the prior owner disappeared before going over the electrical systems leaving us to figure this out, My issue is the electrical is crazy to understand and honestly the DC amps scare the crap out of me. We spent a ton of time removing wire to nowhere and AC wire that was used for speakers. All our batteries are Deka Solar Gel batteries 8G31 (2006) ·  12V Valve Regulated, Gelled Electrolyte sealed Deep-cycle battery. ·  108 Amp Hours at the 100 Hour Rate.  All controlled by three red bank selection switches Bank one -  2 batteries - Deka Solar Gel batteries 8G3 - Starter bank for Ford 192 diesel Bank two -  2 batteries - Deka Solar Gel batteries 8G3 - Starter bank for Northern Lights 5KV GensetBank three – 5 batteries - Deka Solar Gel batteries 8G3 - House bankSo when on shore power all are charging.I put in a 350 amp shunt and battery meter on the house bank that works when on shore power, do I need a Shunt and meter for each bank?1-    When disconnected from shore power should all banks stay charging and connected for topping off from the 200 watt solar or do we need to isolate each bank? 2-    When the Northern lights gen set runs, does it auto switch from shore power? The priorowner ran it for us when we went over the boat prior to purchase and did not cut off shore  power? 3-    How do I tell which bank is on charge and does it matter if you charge all at the same time?We want to add LED lighting, so I am running wire from the extra post connection adapters to three fuse box holders, one in the main cabin, one forward, one in the engine room for the new lights and power for the new diesel heater, and one in the stern near the rear head. I am using these as our power panel is out of extra breakers.

4-    Is there a wire gauge guide for feeder wire to blade fuse blocks?
 5-    Any new book that covers DC, AC and solar power? 6 - Do I need to do a whole boat wire routing plan with all of the chargers, inverters etc.? 7 -Is there a current book that covers electrical  and new generation solar? My tools at handKlein 600 Amp AC/DC True RMS clamp meter (First Klein did not work, had an electrician check it out and he said take it back)Innova 3320 Auto-ranging digital multimeter (love it and now is a go to meter)Cheap black multi meter  (love) I rewired a commercial building with an trade electrician and honestly this is so much more complex and scary.

Thanks in advance!
Jim and Lisa

This doesn't specifically answer your question, but is offered as food for thought:  a few years ago we bit the bullet and ripped out every single wire on the boat (house and engine) as well as the original panels.
It was totally worth it because we now have an efficient system which we fully understand.
We ran a ring of 1/0AWG wire around the perimeter of the boat with power posts and fuse blocks at strategic locations. There is now no device (down to the smallest fan or light) which is not protected by a fuse. Short wire runs mean we can use smaller wires to each device.
We also designed our own DC panels which were manufactured by Front Panel Express.
When we started this project I had no clue about either AC or DC systems. But I consulted with someone who did and then designed our new system which he reviewed and approved.  I now have full confidence that we can handle any electrical issue that arises.
Given the age of these boats and the fact that one has no clue what previous owners did (unless previous owners kept copious notes) it's an option worth considering. I will say it was amazing how much corrosion we found had advanced up each wire run we pulled out due to the original builder and previous owners not sealing crimp points.

Debi
Serenity #110

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Hi Jim. I feel your frustration. I purchased hull #226 about 6 months ago. The electric system was a mess. I quickly decided to rip out every piece of wire with the exception of the ignition wiring. It is quite an undertaking, but in the end I will have total confidence in my system. I found countless wires to nowhere, no marine-grade wiring, corrosion, brittle switches/breakers, etc. etc. etc.
I've added 6 Battle Borne 100ah lithium batteries, a victron 3000w inverter/charger, a victron 3600w isolation transformer, blue sea ac/dc breaker panel, NMEA 2000 for electronics, plus all associated buses, cable/wire, fuses/breakers, etc. I've done all of the work myself. I can't imagine how expensive it would have been if I had paid someone. I still have to add solar panels and other items, so it is still a work in progress.
The main reference materials I have found were the ABYC wire charts and many other diagrams just by googling them. As far as a book goes, I love my "Boatowners Mechanical and Electrical Manual 4/E" which I purchased on Amazon for about $45. It is my bible right now.
Feel free to contact me directly if you have specific questions. I'll do what I can. Best of luck.

Hi Jim,
Wow, that sounds like a lot of batteries!
Seconding Nigel Calder's Boatowner's Mechanical and Electrical Manual. I would highly recommend taking some time drawing out your system on paper and following it through to see if there are any issues. If you've got too much of a rat's nest, draw the system you think you SHOULD have, and then go through and identify what is there and what is extra. 
Here is a diagram from Calder's book that I've drawn on to show how my boat is wired:
 

The switch at the top right to shore power has a LOTO (lock out tag out) with the generator switch. It's just a bar so that if one is on, the other can't be switched on.

Everything that charges my batteries is wired to the positive terminal of the house batteries, ONLY.

• I have a giant fuse in between the AC/DC charger and the positive terminal of the house bank.
• Each solar panel (I have 3) is wired to its own solar charge controller to prevent backflow at night, then to the positive terminal of the house bank. 
• I believe the alternator is wired directly to the positive terminal, but it might have a built in fuse, not sure. It has an internal voltage regulator, though I am considering adding a multistep regulator as well to extend battery life. 

Then, to charge the engine start battery, I use a Xantrex echo charge (series regulator) like the one in the picture above. It acts like a diode so charge can't flow back from the engine battery to the house. But, it's better than a diode because it doesn't require as high of a voltage drop to open. Diodes can trick your voltage regulator into thinking your batteries are charged when they're not. 

I have an identical setup for my generator start battery, though I didn't draw it here.

What if all the batteries are dead and I need to charge my engine battery? Calder recommends an "emergency paralleling switch." I call this a set of jumper cables This gets into your question, does it matter if you charge them all at the same time. The short answer is yes, but for your setup, maybe not. It's also fine for short term on any boat. Here's the long answer: If you charge all the batteries in parallel, they will charge faster, because the total charge acceptance rate will be higher. A lot of boats do this by default if, like yours, they have the same kind of battery for both the house and cranking. Charging different kinds of batteries in parallel over time will result in overcharging one and undercharging the other, decreasing longevity. You can use deep cycle batteries for engine cranking, but the charge time and discharge rate are going to be slower than with a cranking battery. For example, if you're out at anchor and your cranking battery is undercharged, it will be able to start your engine at a lower voltage than a deep-cycle battery, because it can send out more amps instantaneously, which is what your engine needs. So there is a tradeoff to be made here that depends upon your charging habits, like how often you plug in or how often you want to run your generator. 

The flipside of parallel charging, is remembering to isolate the batteries when they are NOT charging. If for example you are fully charged and head out for a night at anchor, using all the lights and stereo and stove and having a grand time, you will run down the house battery. If the batteries are not isolated, then your engine start battery and generator start battery will be drawn down as well. Might not matter if it's sunny in the morning, since you still have solar, but why risk it? Keep them isolated when they aren't charging. 

For metering - I have a meter for each battery bank which runs to my main switch panel. They use the same analog dial display but I can toggle switches to pick which bank I'm looking at. I also have voltage readings from the AC/DC charger, solar charge monitor, and another battery monitor. In spite of having four ways to look at this information, I still keep a good voltmeter so I can check at the terminals, especially when something seems off to me. 

Sounds like you have the right tools. One other thing I'd recommend having in your arsenal is about 50 ft of 14 gage wire. If you are trying to source a disconnect in the wiring (for example, nav lights not working) you can attach it to ground at the battery, and bring the other end with you throughout the boat as you hunt for the problem. That way it's right there to connect your negative probe while you're using the positive probe to poke the live connections, and you'll easily be able to spot a voltage drop.

Hope this helps - have patience! One thing at a time!



 

I totally understand, My boat was hit by lightning before I bought it. And was wired by Benny the blindman so I understand what you are going through. As my boat is 50 years old almost and had lamp cord and other highly reliable wiring in it. Sarcasm intended. I found the easy thing was to rip it all out and rewire the entire boat starting at the batteries. We plan on living upon this for the next 20 years so this was an easy decision. all investment in new breakers, fuses, inverters, solar, tinned marine wire is a small price to pay so we can relax and enjoy our sundowners and happy hours. Please let me know if I can help in any way. We are blessed to have one of the best built, designed boats.

I ordered the book! My other marine wiring books are out of date. The boat was rewired and it looks like he used marine grade wire. The crappy part is we keep tracing and finding wires to no where. Thank you!