Yes. The negative cable from the battery can run to the engine block. The negative cable from the house bank negative bus bar can then run to the same point on the engine block. In a sense, the engine block serves as another negative bus bar.
It is a little more complicated than just "jump the wires." Placing the three batteries in parallel will yield 3 times the amp hours at 12 v. The batteries should be of same type, age, and condition. Ideally all done when new and with all batteries from the same manufacturing lot. In effect the 3 batteries become one big battery. The cables should be run negative to negative, positive to positive. The place mistakes are made is connecting the bank to the house system. The positive cable to the battery switch comes off one end of the parallel bank and the negative cable comes from the negative terminal on the battery at the other end of the parallel bank. If these cables come from the same battery you will only use the first battery, the rest of the batteries will not be used. Making the connections at opposite ends will engage all 3 batteries and draw them down equally.
Is that second lap for the wiring connections or the programming of the Link?
It will be. That's why I wrote the article. A decade ago.
When I first installed my Link 2000 over 15 years ago, I printed out an 8 1/2 x 11 copy of the manual that I downloaded, and left it on the boat (compared to the half sized small manual). That copy has a LOT of notes that I took when learning how to use the Link.
I never really paid attention to 12V systems; on my old C&C it was a basic two battery, 2 bank config with minimal house loads, so we pretty much left it alone. This new boat's 12V and AC configuration was a disaster, so I essentially started over with it. Thanks to this site, the resources and contributors, I think I got it right, and learned a ton in the process. Hopefully I can become a contributor soon and not just a benefactor. I hope to complete the Link 2000 wiring this weekend, so will send an update and some pics, lessons learned.
Sean,
) Because what you should first learn to do is deal with ah in and out. The most important thing I learned from my Link, and one of the reasons I wrote the Gotcha article, is battery acceptance. Do an energy budget, USE YOUR BOAT, and confirm your budget #s. On my boat, with a fridge, my daily ah budget was ~100 ah, which my Link confirmed. Once you've done that, make sure you've done the Gotcha tasks, and see how your charger works on replenishing the ahs. Even with a fridge, your basic maximum load will usually not exceed 5 Amps.
I agree, however, in this context it seems more like: the journey of a thousand miles begins with the first step. Take 'em one at a time and you'll be just fine. All the best, good luck, we're here for input whenever you need it.
