Laptop computer power questions

zugg · 05-26-2008, 09:42 PM

Hi,

Who out there uses a laptop computer in or outside of your van?
I plan on using a 12 volt system with two 4-D batteries.
Is that enough power?
I will have a frig on and using lights at night.
What type of inverter goes well with two 4-D batteries?
Do I need a surge protector while using my computer?
I am doing research way before any money is spent!
Any suggestions would be appreciated!

Thanks,

Zugg

jlrray · 05-26-2008, 09:55 PM

I don't think its really going to matter. How much will you be using it? I've utilized an inverter for a long time with a laptop. Surge protector? I don't put much faith in those things, but on a desktop I would definitely say some sort of UPS is a must. Since you're running your computer from DC you shouldn't be getting any of the fluctuation that comes with AC. Having said that, I'm not an expert with power. Now -- how much drain that will be on your battery? I don't know. Its all just a matter of calculation.

Joe

zugg · 05-26-2008, 10:02 PM

Hi Joe,

Thanks for the reply.
What type of house battery and inverter do you have?

Thanks,

Zugg

jlrray · 05-26-2008, 10:11 PM

I'm not sure yet, what EXACT battery I have. I did look underneath and its seems to be 1 giant battery for the house battery. I saw a recent thread that mentioned 1 battery vs dual batteries, but honestly I don't know whats better. Mine is not bad right now, so that will be on the bottom of my list to fix or replace. I actually have two inverters, both of which I purchased at costco. The latest inverter I purchased is the xantrex 1500. This will power my microwave when on the road.

http://www.costco.com/Browse/Product...lang=en-US&s=1

The other one i have is just a small 400 watt deal. Two 15A recepticles. I'll have to check on the brand tomorrow.

Joe

zugg · 05-26-2008, 10:21 PM

Thanks Joe!

Zugg

John and Dana · 05-27-2008, 01:31 PM

Zugg,

If you have a signle 4D battery it will have a capacity of about 215 amp hours. That means it could run a 1 amp load for 210 hours before it was fully depleted. For maximum life you don't want to draw your batteries elow 50% so you usuable power is about 105 hours. To figure how long the battery will run you load you need to add up the amperages used by each device and divide it into the amp hour rating for the battery. For example, your fridge should draw an average of about 2.5 amps and the computer probably draws another 2 amps while runing. This would give you a 4.5 amp load which would fully deplete your battery in 215/4.5= about 47 hours.

I hope this helps.

John

zugg · 05-27-2008, 02:42 PM

Hi John,

Thank for your response. I appreciae the examlpe as well. It will help me figue out my power needs better!

Thanks,

Zugg

kmessinger · 05-28-2008, 06:07 PM

We occasionally run 2 computers but mostly one at a time. Sometimes for work and sometimes to watch DVDs. Both in and out of the SMB plugged into 110v.

We have a 2000 watt Triplite converter and 1 AGM-4D battery. Since we don't raise the roof (Sprinter) we have 2 solar panels on top.

Computers work fine and don't seem to be a big drain at all.

Regards,

Keith

Joanna · 05-28-2008, 10:02 PM

I have the same energy set up as Keith, and use my laptop plugged into 110 for as long as I care to. I leave it plugged in for recharge while I'm driving.

Scalf77 · 05-29-2008, 04:23 PM

Zugg,
If I understand your post you are building a 12 Volt system only. and in this case you want to use two 4D batteries for extended capacity. If you are thinking of putting in 110 and want a 110 inverter you need to look at what you be running on the inverter and make sure you're inverter will handle that. I must say that the number 1 job of my inverter is to run the coffee pot every morning. if you are just concerned about powering a laptop then you could use one of the smaller point of use inverters and plug your power brick into that. A better option would be to see if yo can find a power brick for your laptop that is for use in a auto.
http://www.powerstream.com/adc.htm

In the case of of the auto or 12 volt power brick you are just doing a DC to DC conversion, in a lot of cases your laptop is running off of 19 volts DC. This would be your cleanest solution and have the least amount of power loss. When you are using an inverter to take 12 v DC to 110 v AC and then back to 19 v DC you are losing some efficiency in all the conversions.

If I your going with 110 laid out in your van with a larger inverter I would just stay with the AC to DC brick, if I had only a 12 volt system would look at purchasing the DC to DC brick , carrying around the small point of use inverter would take up about as much space as the DC to DC brick.

Greg