RV Trip Planning Discussions

Go Back   iRV2 Forums > RV SYSTEMS AND TECHNOLOGIES FORUMS > Going Green
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
 
Thread Tools Search this Thread Display Modes
 
Old 02-19-2015, 12:16 PM   #1
Senior Member
 
BatteryPro's Avatar
 
Join Date: Jan 2015
Posts: 344
Amps per hour? Horsepower per hour?

Quote:
Originally Posted by ;2430852

... use 1/2 an amp per hour.

Some other brands, I have seen, use up to 4 amps per hour...
Quote:
Originally Posted by 2430508
….As an example the phantom draw in our coach is around 4 amps each hour.

[moderator edit] I show [moderator edit], for example, a 10 amp PV solar module. They then ask me, is that 10 amps per hour?

Let’s look at this often used phrase, “amps per hour”. You see it used quite often in forums discussing power. Would you believe that this phrase is meaningless? It is! If I told you my car can produce 400 horsepower per hour you would wonder what I am saying. Am I saying it’s 400HP only if I run it for 1 hour? Or, does it take 1 hour to make 400HP? What if I only ran it for 1 minute? Then would I say it is 400HP per minute? Again confusing.

Amperes or amps is the term that defines current flowing in a circuit. If I turn on a load that is drawing 10 amps, it does not matter if the time is 1 second, 1 hour or 1 week. It is just a measure of current flowing and time has nothing to do with it.

The confusion comes from another term that does relate to time, “amp-hours” or AH. It is a reference to a quantity of something, much like a gallon is a quantity of a liquid. Amp-hours are a quantity of current flowing multiplied by time. A 10 amp load running for 1 hour is 1AH. But what if the load is only for 30 minutes or 0.5 hours? Multiply time (in hours) by the load: 0.5 X 10 = 5AH. If the load was for just 1 minute it would be 0.16 AH used.

The same applies to the term Watts and Watt-Hours. Watts is a measure of power, Watt-hours is power over an amount of time.

So, there is no such thing as "amps per hour" like there is no such thing as HP per hour.

Amps = current
AH = current over time
Watts = power
Watt-hour = power over time


Larry
__________________

__________________
I have a vast knowledge about PV solar, batteries and inverters. I'll try to provide the best answer if I know it and hopefully correct some "Campfire" talk. Full-time 1999-2004. Part time now. '92 Hawkins, 360AH Lithium Battery, 1480 Watts PV solar.
BatteryPro is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 02-19-2015, 12:42 PM   #2
Senior Member
 
tncruiser's Avatar
 
Ford Super Duty Owner
Join Date: May 2009
Location: kingston tn.
Posts: 974
if it were I ,Iwould draw an analogy of mpg @ idle vs parasitic draw under a no switch load draw. When I was a young lad I sold floor care at sears an engineer wannabe metal clipped scale in front pocket and all told me there was no way a vacuum clnr could be 3.5 hp and if I proved it he would buy my best model (can you say $55.00 commission in 1965) so I explained ohms law and locked rotor amp draw (which is the industry standard) and "learned him how it r done" then asked will that be cash or charge ,HE CHARGED IT
brianj
__________________

__________________
just liven life in east tn or where ever our
2011 georgetown ,2016 explorer and 2015 "hemi" ram take us
tncruiser is offline   Reply With Quote
Old 02-19-2015, 01:32 PM   #3
Senior Member
 
BatteryPro's Avatar
 
Join Date: Jan 2015
Posts: 344
This is the problem with evil minded marketing people. They use deception and guile to steal from lesser intelligent people. The deception in this case is advertising a 3.5HP motor which obviously (to you and me) is not turning under LRA so no vacuuming is happening. The instant the motor starts turning, current is greatly reduced until the 1/4HP motor is sucking up the dirt.

I remember seeing 2000 Watt car stereo amplifiers for $49.95 weighing all of 8 ounces. Same lie.
__________________
I have a vast knowledge about PV solar, batteries and inverters. I'll try to provide the best answer if I know it and hopefully correct some "Campfire" talk. Full-time 1999-2004. Part time now. '92 Hawkins, 360AH Lithium Battery, 1480 Watts PV solar.
BatteryPro is offline   Reply With Quote
Old 02-19-2015, 03:24 PM   #4
Senior Member
 
wa8yxm's Avatar
 
Damon Owners Club
Workhorse Chassis Owner
Join Date: Mar 2009
Posts: 24,023
I have never seen (Before your post) the phrase "Amps per hour"

What I have seen is "Amp Hours" which does have meaning and is totally different.. And I have seen so much confusion that I believe it is our 52 state (we have 53 if you count Washington DC as 51, and Denial as 53)

Amp hours is usually expressed as a quality of batteries and is at the C/20 rate. So a battery rated 100 amp hours, can deliver 5 amps for 20 hours (C=100/20hours)

SO a 10 amp panel, in full sunlight, in theory can deliver about 10 amp hours NOT amps per hour, but Amp hours.

In reality, most of 'em max out about 5
__________________
Home is where I park it!
wa8yxm is offline   Reply With Quote
Old 02-21-2015, 10:58 AM   #5
Senior Member
 
Join Date: Dec 2013
Posts: 164
Quote:
Originally Posted by BatteryPro View Post
...

A 10 amp load running for 1 hour is 10AH.

...

Larry
Fixed your post.
__________________
1998 Kit 23' TT, 210 AH, PM4B-45, RV-30S PWM, 280w solar, Trimetric, Wave 3, Samlex PST-150w
2004 Nissan Titan 4x4 with Tow, Hellwig helper springs, Banks Catback
BendOR is offline   Reply With Quote
Old 02-23-2015, 06:04 PM   #6
Senior Member
 
BatteryPro's Avatar
 
Join Date: Jan 2015
Posts: 344
Quote:
Originally Posted by BendOR View Post
Fixed your post.

Oops! Fixed Indeed. Thanks for that.

Larry
__________________

__________________
I have a vast knowledge about PV solar, batteries and inverters. I'll try to provide the best answer if I know it and hopefully correct some "Campfire" talk. Full-time 1999-2004. Part time now. '92 Hawkins, 360AH Lithium Battery, 1480 Watts PV solar.
BatteryPro is offline   Reply With Quote
Reply

Tags
power



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
15th ANNIVERSARY CELEBRATION RALLY Madame Boomer Texas Boomers 31 05-19-2015 03:36 PM
Amp Hour Consumption len poleshaj Winnebago Industries Owner's Forum 16 12-09-2014 09:22 AM
How to add an hour meter to Onan generator? bokobird RV Systems & Appliances 3 09-15-2014 04:49 AM
Question about horsepower MO Fred Cummins Engines 14 06-27-2014 08:11 PM
Rv park near Brooklyn NY or even an hour away. illusionist Camping Locations, Plans & Trip Reports 5 02-09-2014 12:24 PM

» Featured Campgrounds

Reviews provided by


All times are GMT -6. The time now is 07:43 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
×