Dc power onboard

[bekasi]

If a vessel wants to be purely reliant on DC power,what are the requirements ? What sort of calculation is needed? Inverter for microwave?? No heating,airconditioning will be used at all.Only a refrigerator(DC powered),microwave,& a reasonably large DC powered Freezer unit will be used.
Have been looking at:

http://www.whispergen.com/main/dc-marine/

http://www.whispergen.com/main/dcmarinespecs_info/

http://www.fridgetech.co.nz/page/97/

Any wise advise will be very highly appreciated.Operation shall be intermittent for 2-3days .

 

[Assassin]

First you will need the largest battery bank you can afford, then you will need to calculate the actual input power of everything your inverter will power, but you need to be aware of several things.

Microwaves state cooking power, not actual input power which can be up to two and a half times higher than cooking power, and it varies from model to model; so check the manufacturers specifications carefully. This applies to many other items, so check them all out and add up the total input power requirement before even thinking of your inverter. Inverters vary in quality and performance, so buy a quality product which is suitable for electronic devices such as computers, mobile phone chargers, etc, cheaper models are often not suitable for electronic items.
Fridges and freezers are notorious for the manufacturers information regarding power consumption, this is generally an average for a prescribed limited working range such as keeping it cool when it is at working temperature. Often it does not specify the actual increased load needed to get it down to temperature, or when it is running in hot conditions where it works harder than normal.

Work out everything running on 12 volts, then split the battery packs, keep a smaller one for running 12V systems, and one purely for the inverter. If you have a problem with one circuit you only lose that circuit which will most likely be the inverter, if you have 12v lighting it will remain working.

Mount the inverter as close to the batteries as possible, use the right size, or larger cable and ensure the ends are crimped on correctly, use the correct crimping tool, or pay a specialist to crimp them on. Make sure you have an isolator switch to shut off the inverter.

Run everything through a fuse board of the correct size and type to prevent problems.

 

[Elessar]

If a vessel wants to be purely reliant on DC power,what are the requirements ? What sort of calculation is needed? Inverter for microwave?? No heating,airconditioning will be used at all.Only a refrigerator(DC powered),microwave,& a reasonably large DC powered Freezer unit will be used.
Have been looking at:

http://www.whispergen.com/main/dc-marine/

http://www.whispergen.com/main/dcmarinespecs_info/

http://www.fridgetech.co.nz/page/97/

Any wise advise will be very highly appreciated.Operation shall be intermittent for 2-3days .

go and ask on the liveaboard forum. These guys live for years without shorepower and without often putting their engines on either.