Quote:
sv_makai once whispered in the wind:
Due to a second faliure of our herat charger invertor makai has been switched to a invertor with a seperate charge. Though we never use the charger in a marina except to equalize the batteries.
After the failure and the cost to ship the charger to st martin for repairs and return it we decided to install a Prosine 1750 invertor (biggest we could get in the Caribe) for 455 US. In the US we saw 299 price tags. We have a shore power\ invertor switch that allow us to chose the source. At anchor which is mmost of the time we are on the invertor. it works well and has a fairly good overhead so the waste amps is only about 20%.
For the laptop we had a dc-dc 12 volt to 19 volt invertor made. It has even a lower over head as it plugs directly to the battery system. Huge losses occur when using the invertor to go from 12 to 110 and 110 to 19 volts (most computer charge rates). A good invertor losses 20 percent or more from 12 to 110 and then again from 110 to 19 volts.
Also the dependence upon the invertor to charge the computer batteries is eliminated. We would have been hosed as we were without an invertor for 8 months the first time and 2 months the second. |
Hmmm... good points. Being able to just junk a small inverter and buy a new one for $200-$300 is very attractive. No worries about a failure taking out the entire boat's ability to generate AC from DC sources. Plus, I suppose you could switch inverters around if one went out... allowing you to still use all the components.
It's not efficient, but all of a sudden (since I figured out the most efficient way to refrigerate at anchor), I have excess DC capacity even at a couple hundred Ah. These batteries will be topped off every day by a genset run, or by motoring on some occasions.
I'm not sure I'm anywhere closer to a decision. Kai Nui and Bill make good points. I suppose I have to sit back now and reason this out, taking the tools and reliability factors into account.
This is a tough one!
PS: I wanted to do the DC transformer as well for my latop, but decided to just live with the inefficiency for the time being. In a perfect world, that is the best solution. But... I have other equipment in the same area that has to run off the inverter - for instance - a router and an amplifier for my WiFi signal. So... I would still need AC there anyway. Sometimes, I wish I didn't need all this junk and could just do normal sailing. Our customers require this kind of stuff.