batesrt
ohio
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Hi I'm pretty new to RV'ing so sorry if this has been asked a million times.....
We bought a used 20' travel trailer, and are mainly boondocking it at races. It's always insanely hot in the summers, so the main thing I'd like to run is a little 1 amp box fan (since AC is not an option). I am just using a little power inverter to plug the box fan in to.
I bought a brand new deep cycle marine/rv battery (Everstart MAXX from Walmart), charged it up several days (using the supplied RV electrical cord from my house). Tried out the box fan and one little light bulb to see how long they lasted...... 8 hours and the battery is totally dead! The fan is only listed as 1 amp, so shouldn't that last for several days at a time?
So went back to Walmart and swapped the battery for the largest one they had (MAXX 125 amp hr deep cycle). Charged it all up, and again with the fan and one little light on it lasted less than 16hrs !
If I have a battery that is 125 amp hours, and I'm running say just a 1 amp fan......shouldn't that fan last in theory nearly 125hrs ???
Any help on this subject would be great thanks!
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donn0128
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One battery will not last very long. If you are going to be boon docking you really need at least two batteries. Preferably golf cart 6 VDC deep cycles. What you may be getting from Wallyworld is a combination battery and they will not work for long. In reality a single battery running a fan for 16 hours is pretty good. once you add up all the parasitic draw plus the fan if you get 8 hours on a single battery,you will be lucky.
Donn,Lorri,Max (The Rescued Lab)
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Chakara
New Mexico
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I hope my math is right here, but 12V 1amp is much less than 1amp @ 120V.
Watts=Volts * Amps
So:
120V@1A = 120W
120W / 12V = 10A
Not counting loss from the inverter, your 1A fan pulls 10A from the batteries.
Is that right guys?
-Chak
- 2005 Dodge 2500 5.9 standard
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Son of Norway
Denver, Colorado
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Chakara stated your problem exactly. Try using a couple of DC fans.
Miles
Miles and Darcey
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batesrt
ohio
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Son of Norway wrote:Chakara stated your problem exactly. Try using a couple of DC fans.
Miles
So basically the power inverter is the issue causing it to drain way more than I thought?
Maybe a dumb question but do the DC fans just connect directly wired to the battery?
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batesrt
ohio
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.....also any idea how many amps my little roof vent ceiling fan would use?
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Chakara
New Mexico
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Your fan probably draws 1-4 amps. I found a chart At this RV Solar site that you could use for rough guessing on the draw of stuff.
Many RV's have cigarette lighter type outlets that you could use to run a DC fan. That should be MUCH nicer on your battery. Otherwise you may need to tap into the electrical system to install one. They are very handy for things like this as well as charging gadgets like cell phones.
Hope this helps!
-Chak
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Huntindog
phoenix arizona USA
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Fans pull a lot of juice. For example, most find that the heater fan is by far the biggest draw on the battery. Figure one night of heat per battery for most people.
The inverter is not the big problem. But you are looking at a 1 amp rated fan that is 110 volts. Convert that draw to 12 volts and it is no longer 1 amp.
A 12 volt fan that moves the same amount of air will not be any more efficient other that the tiny amount of power lost in the inverter.
Figure around 10% on average for that.
For what you are trying to do, a small cheap generator will probably work better. You can get 900-1000 watt generators for less tha 100.00 on sale. That will run just about any fan, with power to spare.
Huntindog
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Chakara
New Mexico
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Oh yeah, I was just thinking about this and remembered that I installed a MaxxAir TurboMax fan. On low speed it pulls 1.4A and moves a LOT of air. High speed is 4A and I bet changes the air out in the trailer in a few minutes. I love it and it was easy to install....
Check them out here.
Plus you get fresh air when its raining - and stay nice a dry.
(I have no affiliation, just a love of the product - there are other brands that are likely just a good)
-Chak
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skipnchar
Topeka or somewhere else
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Joined: 12/17/2003
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Tell you ANOTHER little fact about the Everstart....it will die for good after very few of those deep discharges. Never found one that would last over a year when used in the trailer. Marine/RV batteries are basically starting batteries (boats need starting batteries) and they don't stand up well to deep discharges.
Good luck / Skip
2011 F-150 HD Ecoboost 3.5 V6. 2550 payload, 17,100 GCVWR -
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