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Power Consumption?

Posted: Sun Jan 25, 2009 1:41 am
by AAMFlyer
I need a little help... I noticed that the specs are saying the ebox runs at about 8 watts... How are you measureing that...

What I'm trying to do is determine the power requirements for running meteohub along with a wireless/mobile broadband router from a remote solar powered station.... So need to try and come up with a measure in amps/hour for the ebox and the router so I can size the panel and battery..... The router was listed as 1A/12V DC... Thoughts?

Thanks!

Re:Power Consumption?

Posted: Sun Jan 25, 2009 1:45 pm
by skyewright
AAMFlyer wrote:I need a little help... I noticed that the specs are saying the ebox runs at about 8 watts... How are you measureing that...
I can't speak for Boris, but while a theoretical calculation is possible (even easy) it is probably also useful to plug the unit(s) into the mains via a plug-in power meter and see what they really draw.

This is what I use.

As well as giving an instananeous reading, these sort of units also usually give accumulated readings, so you can, say, leave it running for a week and look at the long term average too.

Re:Power Consumption?

Posted: Sun Jan 25, 2009 8:29 pm
by sevenless
And if you're in North America, I can vouch for the Kill-A-Watt meter... it has all the same featured mentioned above but for this market.

With regard to power draw, if the ebox is drawing 8 watts, then (assuming it also uses a 12 volt DC supply) you will need a supply rated at 0.67 amps at minimum (W = V*A). Furthermore, supplies are typically rated a bit above the requirements for the system they are powering because there's always the chance that although a system runs at 8W, it might need a bit more wattage when powering up or under momentary heavy load.

Also, amperage is additive, so to power both the ebox and the router you will want a supply rated to at least 12V/2A, and probably 2.5A to be safe.