inverter / alternator ?

[twiggsmcgee]

I run a deep cycle wet cell battery for cabin lights, running lights and my vhf set up. Should I think about running an inverter for shore power as I upgrade to new electrical systems and what can you tell me about marine alternator usage under such a low electrical load

[skipmac]

I'm not quite certain I understand what you're asking so let me try to clarify.

- When you ask about using an inverter for shore power I assume you mean you want to use and inverter to make 125V alternating current (they kind of electricity used on shore) to power things on your boat that use AC electricity like a blender or microwave or power tools?

- Can you explain what you mean by "such a low electrical load"? Are you referring to the inverter? If so, an inverter can be a very large load, depending on how large the inverter is and what you're trying to run.

An example, I have a 2 kW inverter (2000 Watts) and if I use the full output of the inverter then I would be drawing over 170 amps from my batteries. That is a LOT of power. Even a small inverter can draw more than you think because you are converting 12V DC to make 125V AC. That means very roughly you need 10 times more amps DC to make the same number of amps AC.

- Alternator usage? You need to size your alternator based on the total amp hour capacity of your batteries and how much you pull out of the batteries every day. So you need to figure how much you draw from everything: lights, stereo, radio, GPS, etc, AND the inverter.