Electrical Requirement Info?

[cabledave]

can anyone suggest a source of info for figuring amps/watts/ volts. ie how many batteries do i need to use an inverter to power a refrig and how big solar panel to charge battery and so on.....

[S/V Illusion]

There are a myriad of sources if you did a simple search. Start with the Ample Power Primer which will give you a basic understanding which is a requisite to fully understand the options available to you. There is also a huge selection of book you could read...

Ther is an incredible amount of info readily available to you with even a modest effort to look and similarly there are probably 100 threads on this site with similar discussions you could search rather than replicate all here.

[Ex-Calif]

Hi Dave - Aside from some excellent books there are lot's of threads here about power requirements for boats. As always there are lots of opinions.

You could try the custom search engine to find older threads on this:

Cruisers & Sailing Forum

Here is a link to a search result.

electric power charging - Google Search

[cabledave]

thanks for the info...my first boat has onboard a solar panel, inverter, small refrig. The solar panel charges the 2 batteries. but the inverter and the refrig are not wired up they are only onboard. I also need to get the running lights working properly. Being new to this site as well as boats I thought I would ask of any book reccomendations others have found helpful. Possibly a "Sailboat Wiring " type book. Thanks

[S/V Illusion]

Originally Posted by cabledave

thanks for the info...my first boat has onboard a solar panel, inverter, small refrig. The solar panel charges the 2 batteries. but the inverter and the refrig are not wired up they are only onboard. I also need to get the running lights working properly. Being new to this site as well as boats I thought I would ask of any book reccomendations others have found helpful. Possibly a "Sailboat Wiring " type book. Thanks

"Boatowners Mechanical and Electrical Handbook" by Nigel Calder is among the best, most thorough, easily understood and most recommended books

[haurakiinc]

a 6v 220amp hr battery will give 220amp at 6v for 1 hr if you run a 240v fridge you will nead a lot of power a 400w fridge will need a 1000w inverter for start up then 400w to run first thing you will nead to do is go and get the wats or amps of all that you want to run and then how long each will run for that will give your power nead per day (volts x amps = wats ceck that with sparky i get wrong way round ) or get info and e mail solarsparkie@xtra.co.nz

[GordMay]

Ohm's & Watt's Laws define the relationships between (P or W) power in Watts, (E or V) voltage in Volts, (I or A) current in Amps/Amperes, and (R) resistance in Ohms.

Ohm's Law: E = IR ; I = E/R ; R = E/I

In direct current resistive circuits, instantaneous electrical power is calculated using Watt’s Law:

Watt’s Law: P = EI ; I2R ; E2/R

[haurakiinc]

thanks for that can never rember

[redcobra]

Never put PIE in your EIR.
Now you'll never forget

[Glenn C]

try the Victron blue book. Free download from their site and has an interesting spin on the inverter based boat. I also found Nigel Caldrs book an excellent reference, and Nigel gets into some good discussions on pros and cons of various systems.