Using a car battery to power an inverter?
 

Now, I know it's possible to power an inverter off a car battery, but I'm curious about buying a spare battery and using it for 8 hours a day in tandem with a 800w inverter to power a laptop (non gaming). I got another job way closer to home (6 miles instead of 40 each way) and I need to keep myself busy as this post is boring. I would normally just use my car battery but I really don't want to strain it like that. So, real question is...

Is it possible to just use a big battery, say a RV battery that I trickle charge every night while I sleep to power an inverter for 8 hours? Or will this not work for some reason?

How much power are you using, and how much power is available in a fully charged battery.

I have no idea, that's why I'm asking. I'm thinking about powering a small laptop just to watch movies and TV shows on, not over wifi just off a USB stick. It will probably be a 13" or 14" laptop. I would think maybe 1-400w at most? If I can find a small DVD player that plays movies and TV shows off USB sticks I'll use that instead because I know that draws a lot less power.

Laptops don't take 800W to power; more like 100W when charging, and perhaps 20W in regular use.

Just get a laptop that can run for 8hrs without a charge. Mine goes 10hrs on a single battery. Multiple laptop batteries is also a better option than running a lead-acid with an inverter.

I'm assuming you are asking about "I got another job way closer to home (6 miles instead of 40 each way) and I need to keep myself busy as this post is boring.".

I'm assuming Balto is talking about a guard post and not this forum post. My guess is they are in security or some other monitoring situation where action is usually not required.

Most cheap inverters are not designed to run for 8+ hours at a time and will burn out, you would be better off getting a car charger for your lap top, a lot of lap tops are ~17 volts or so, so you might be able to just power it off a 18v cordless tool battery for about the same cost as a cheap inverter and it would fit in your pocket.

Sorry for not being more specific, yes I'm a security guard lol. I work graveyard at this job (11PM to 7am). Again, I didn't think about getting multiple batteries, but I don't know how I would charge them at work, or at home while I'm sleeping I would only be able to charge one at a time... As for a car charger, again not a bad idea, but I don't want to put the extra strain on my actual car battery and risk trapping myself at work.

don't use an inverter if possible. you would be converting DC to AC back to DC with every step along the way losing efficiency.

Do you already have a laptop for the job, or would you be buying one? You can get external battery chargers to take care of charging several batteries, but I would check on their availability before buying a laptop (business class laptops like Thinkpads would be more likely to have them).
What about an Android tablet or ipad? They already have great battery life and would work great with an external battery similar to what Xist posted.