I'm going to resurrect this thread. Reading through it I fine it very informative.
I'm shopping for an inverter. Seems like a great use would be to charge a computer, phone, heat something in the micro and the small things. And to be able to run a fridge or ice maker would be huge.
I've got no problem cranking the genny, if necessary. It really doesn't cost that much to operate. However the convenience of having those little things available virtually all the time is great.
So... a few questions.
Seems like the cheap ones, that simple plug into the battery system and you plug your 110v item into them would be a PITA. I'd like one that ran ALL the 110v items on the boat and I'd just monitor it with regards to loads (or have some sort of automatic load "control" on the inverter.
About the wiring, can anyone draw a diagram that shows how to wire and inverter? And typically where do you put it? Suspect it would be idea to be close to battery switches?
Now, good comments on some of the models. Is there a point that has diminishing returns when going bigger? Suspect thea 1500watts would cover most of whats needed?
And what kind of battery bank is big enough, and would it be wise to consider a bigger alternator?
Thx.
You're wise to be looking at the whole picture, some planning at this stage will pay dividends in a system that will work from the get-go with less chance of having to modify it after install just to make it functional.
Start with what you want the system to do. Add up the power requirements to determine a capacity for the inverter; run time for the loads in 24 hrs. will give you an amp hr. requirement, 2X that's going to be your battery bank size (unless you use lithium batteries) since you want to only discharge the bank to 50% DOD (depth of discharge). With that determined, ~15-20% of the battery amp hour capacity will be the minimum alternator capacity. The alternator should be externally regulated, preferably by a "smart" regulator. The size of the inverter and the distance to the battery bank will determine the cable size. Battery choice is a separate issue with its own ramifications. The choice of lithium changes the whole ballgame.
I would consider a full sine wave inverter, far more compatible with more devices. Unless you have a charger that has the capacity for ~.15C (C=battery amp hour capacity, so for ex. you have an 800AH bank, your charger should be able to produce about 160A), you'll probably be better to use an inverter/charger combination. An inverter/charger system without a battery monitor will leave you guessing the status of the battery bank, so figure on a battery monitor. I, like others am partial to Magnum, and like others, would stay far away from Xantrex.
If you plan a DIY install, make sure your skill set is up to the challenge. There are many details that can easily be overlooked and can create significant operational problems, and even more serious safety considerations, particularly co-mingling of neutral/ground conductors, cabling of the 12V, setup of the battery bank, alternator and related overcurrent protection. If you don't have a good grasp of those concepts, then you should consider enlisting the help of a marine electrician. A dock buddy who is an electrician (but not a marine electrician) and offers to help with the installation probably does not have a clue about marine application of an inverter, let alone proper 12VDC wiring.
An inverter is a significant improvement to a cruising boat. If done right, it can be a trouble-free system that will give you many years of benefit.
Hope that's helpful.
