View Single Post
Old 05-11-2008, 12:02 PM   #2
Marin
Scraping Paint
 
City: -
Join Date: Oct 2007
Posts: 13,745
RE: inverter while running......

I don't see why not as long as the AC and DC loads don't exceed your alternator output. We use our inverter (Heart Freedom 25) occasionally when running to power the microwave, vacuum cleaner, or battery charger (phone, camera, laptop, portable VHF radio batteries). Whether or not the alternator(s) can keep up with the combined draw of the inverter and the boat's DC requirements will be dependent on the output of your alternator(s) so you need to find out what that output rating is. If you have ammeters in your system you should be able to tell if the alternator(s) are keeping up or not. If they're up to their maximum amperage then perhaps not. If they're not producing their maximum amperage than they're probably keeping up with everything.

Our boat has stock Motorola alternators (about 45 amps each) and its as-built battery system (two 8Ds plus a 4D for the generator). So we have a pretty minimal electrical system by today's standards. When we're running we put the battery switch on "All" which combines the output of both alternators. The inverter runs off the port battery only, so combining the alternator outputs means both alternators will pick up the load if we use the microwave (or the anchor windlass which draws a lot of DC current). Leaving the switch on "2" (the port battery we normally use as "house") means each alternator will only charge the battery on its side of the boat. So the port alternator will have to pick up the entire DC and AC load while the starboard (start) battery just goes along for the ride.

But before you can accurately answer your question you need to find out what your alternator output rating is. You can't determine your ability to keep up with your electrical load without knowing this figure.

-- Edited by Marin at 14:04, 2008-05-11
Marin is offline   Reply With Quote