Easy Power source?

[PKCSPT]

So as I have said before I am not very patient to build/put things together.
Don't want to add solar at this time with trying to keep my weight as minimal as possible.
I usually just camp overnight, just need enough power to run my computer (I use to watch movies if it is raining) for a few hours and a small fan overnight.

Thinking a small battery that I would charge before I leave. Where would I find what I need to hook the puter and fan to the battery and would the battery last overnight? Simple quick easy and not too expensive,,,,

[GuitarPhotog]

How much current does the computer power supply draw from a 12VDC source? That's going to be the determining factor.

My Dell uses 8A @ 12 VDC (i.e., 96 Watts) when running the DVD player. That means I need 8 Amp-hours of battery capacity for every hour I'm going to use my laptop on trailer power. A 2 hour movie therefore uses 16 AH of my total 60 AH battery capacity.

If you use a Fantastic Fan (which uses ~3A at full power) for 8 hours, that's another 24 AH of power.

So this scenario uses 40 AH of power every 24 hours. It is recommended that you not use more than 50% of the capacity of your battery before recharging, so you will need an 80 AH deep cycle battery, and a charger suitable to charge and maintain such a battery. BTW, an 80 AH deep cycle battery will weigh ~50 lbs, not a simple thing to hoist in and out of the trailer every trip.

I suggest you read some of the battery threads and FAQs, decide on an energy budget (lights, fan, computer, phone charger, etc.) and then specify a battery and charger that will meet your requirements.

<Chas>

[PKCSPT]

Well 50lbs is a bit more weight than I was looking for. I had looked at other battery threads but your explanation really broke it down in terms that made sense to me. I run an HP laptop which probably has about the same draw as your Dell.
Back to waiting til I can afford a solar panel, larger tow vehicle.
Thanks for the help.

[jss06]

Well 50lbs is a bit more weight than I was looking for. I had looked at other battery threads but your explanation really broke it down in terms that made sense to me. I run an HP laptop which probably has about the same draw as your Dell.
Back to waiting til I can afford a solar panel, larger tow vehicle.
Thanks for the help.

To watch movies, get a cheap tablet. My samsung Galalxy Tab will run 8 hours on a single battery charge while watching movies. Then you just have to worry about the fan draw. I have run a Fantastic vent for 2 days on a Optima Blue top battery without recharging.

The great thing about an automotive battery is if you wire the trailer accordingly you can recharge the battery while you are driving around. Or if you are camping for an extended period of time you can hook up your tow vehicle and recharge tha battery when it gets low. You just need a trickle charger or other way to maintain the battery when it is in storage.

[bigbendhiker]

Well 50lbs is a bit more weight than I was looking for. I had looked at other battery threads but your explanation really broke it down in terms that made sense to me. I run an HP laptop which probably has about the same draw as your Dell.
Back to waiting til I can afford a solar panel, larger tow vehicle.
Thanks for the help.

You may also be able to get a spare battery for your HP laptop. Charge both laptop batteries before you leave home. You could then run your laptop off its batteries and if you run your Fantastic Fan on a lower speed you could get by with a much smaller trailer battery.

Based on your planned usage, solar won't alleviate the need for a suitably sized battery. All of your stated usage is at night or in the rain. Solar would help recharge your battery during sunlight hours so that you could camp for more than one night at a time, but it won't help at night or in the rain. Your best bet is to reduce usage or find a way to accommodate the weight of the battery.

Good luck!

[Richard A.]

Please note that some/many laptops run HIGHER than 12volts. Check yours to be sure. It may be listed on your power supply.

[8ball_99]

There really isn't a lot you can do but cut usage.. Like others said the panel will only help during the day. For one night trips thats not really any help. We show up with charged batteries which gives us more then enough for the afternoon-evening and morning. Thn the panels recharge the batteries which puts back what was used over the night and during the morning time.. I also run my fans during the day to help keep the trailer cool. Since I have plenty of solar to replace the usage we don't worry at all about usage during daylight hours. If I wasn't using power the charger would just be off doing nothing. Deep cycle batteries are heavy. The weight pretty much = amp hours.. The lighter the battery the less run time you have..

[GuitarPhotog]

Please note that some/many laptops run HIGHER than 12volts. Check yours to be sure. It may be listed on your power supply.

Most laptops want 19-20 VDC at the charging input. My Dell came with a power supply that accepts 12 VDC in, and provides 19.5 VDC out. The 12 VDC input is more efficient (takes less input current) than the 120 VAC input for some reason.

<Chas>

[Richard A.]

Also note that if all you use that laptop for is to view DVD's then it may be worth your while to get one of those portable DVD players. All the ones I've seen have a rechargable battery that will usually last for one movie .. but the input is 12volts (at least of the ones that I've seen .. and I own two)

The screen is smaller than the usual laptop but how far away do you plan on having it in your trailer.

[Lgboro]

You could build in computer fans like many of us have and all led lights. That will reduce your consumption by quite a bit and still move plenty of air in a tear and extend the time you battery will last.

[rebapuck]

Take a book.

[Techguy]

One thing you can do to make the computer's battery last longer would be to copy the movie to the hard drive and turn off the DVD drive motor. The computer is going to require the hard drive to run while it's on but it runs a second motor... the DVD player motor to play a movie. A dedicated DVD player has electronics to provide the operating system and skip the hard drive allowing it to run the DVD player's motor. Some computers will play a DVD without an operating system, this may make the battery last longer if being used to only play a movie. Turning down the brightness of the screen will also make the battery last longer.

If you had a solar charger, you may be able to charge the computers battery during the day. That being said, I prefer a campfire and the sky to a DVD, or some company to chat with or...