Power Inverter Question
#1
Registered User
Thread Starter
Join Date: Jul 2003
Location: Virginia
Posts: 97
Likes: 0
Received 0 Likes
on
0 Posts
Power Inverter Question
I've done the searches to find out about power inverters but couldn't find out what size can safely be run from the 12V power outlet in the back of an 03 Runner for extended periods of time. It appears that limiting it to 150 or 400 watts is the only way to get the 12V plug on one and that is really all I need (basically to charge/power a laptop) but wanted to make sure that isn't too much of a continuous draw on the wiring for that outlet. I know it comes as a 120V outlet as an option (or standard on the LTD, not sure which) but have no idea what the output is when configured that way (or if the wiring is different). Any help appreciated.
#2
Registered User
Tom,
there's a similar thread going on about this topic, though it has more to do with installation and the right equipment. You might want to keep an eye out on it too.
I'm sure others will speak up b/c I am definitely not an electrical expert, but I do know what was recommended to me by others and my local electrical/fuse supply shop.
My 12v plug outlet could only support a 400W power inverter. However, certain accessories like laptops could *not* be reliable supported. For example, I'd plug the supplied 12v power inverter plug into my 4runner's accessory plug and sometimes it would just cut out after booting. Not enough juice? That was the simple conclusion. However, a cell phone recharger (110V plug) could easily be supported---two in fact with a power strip.
So I followed what Corey did and did my own: http://www.4runners.org/articles/dist
It takes more work but its definitely worth it. It will handle everything. Even more so since I purchased a gel-cell battery prior to the installation.
Good luck,
Bob
there's a similar thread going on about this topic, though it has more to do with installation and the right equipment. You might want to keep an eye out on it too.
I'm sure others will speak up b/c I am definitely not an electrical expert, but I do know what was recommended to me by others and my local electrical/fuse supply shop.
My 12v plug outlet could only support a 400W power inverter. However, certain accessories like laptops could *not* be reliable supported. For example, I'd plug the supplied 12v power inverter plug into my 4runner's accessory plug and sometimes it would just cut out after booting. Not enough juice? That was the simple conclusion. However, a cell phone recharger (110V plug) could easily be supported---two in fact with a power strip.
So I followed what Corey did and did my own: http://www.4runners.org/articles/dist
It takes more work but its definitely worth it. It will handle everything. Even more so since I purchased a gel-cell battery prior to the installation.
Good luck,
Bob
#3
Contributing Member
Unless you're planning on dropping some serious change on a pure-sin wave inverter (300+$), you'd be much better off just getting the DC converter for your laptop. Laptops are sensitive little buggers, and don't like the barely modified square wave power produced by most economical inverters.
I ran mine off a cheapo inverter, and the laptop AC power supply got *hot* pretty quickly, followed shortly after by the 12v DC outlet cutting out entirely. There's another thread on that running around here somewhere, but that's my experience with it.
I'm gonna buy the DC adapter for my laptop... much cheaper, and I imagine a hell of a lot more efficient than going from:
alternator AC -> rectifier etc. DC -> Your Inverter AC -> Laptop power supply DC ...
I ran mine off a cheapo inverter, and the laptop AC power supply got *hot* pretty quickly, followed shortly after by the 12v DC outlet cutting out entirely. There's another thread on that running around here somewhere, but that's my experience with it.
I'm gonna buy the DC adapter for my laptop... much cheaper, and I imagine a hell of a lot more efficient than going from:
alternator AC -> rectifier etc. DC -> Your Inverter AC -> Laptop power supply DC ...
Last edited by Scottiac; 12-01-2003 at 04:15 PM.
#5
Contributing Member
Bob,
Not yet... Probably the john-q-generic recommended-by-dell one that will no doubt be listed on their web site somewhere! :-)
"Hot" in this case meant a fair bit warmer than you'd want to hold on to, not melting-kind of hot. But when running off clean power, it never heats up nearly as much.
The other motivation is that I can't see going through an extra DC -> AC -> DC cycle can be all that efficient.
Not yet... Probably the john-q-generic recommended-by-dell one that will no doubt be listed on their web site somewhere! :-)
"Hot" in this case meant a fair bit warmer than you'd want to hold on to, not melting-kind of hot. But when running off clean power, it never heats up nearly as much.
The other motivation is that I can't see going through an extra DC -> AC -> DC cycle can be all that efficient.
#6
Registered User
Thread Starter
Join Date: Jul 2003
Location: Virginia
Posts: 97
Likes: 0
Received 0 Likes
on
0 Posts
Now I'm confused (well, I was already confused, now more so). My laptop is a Compaq with a Lithium Ion rechargeable battery and the instructions say it is fine to run off AC with the battery installed - basically running through the battery with a continuous charge going to it. In this case, since it's basically running off the battery, wouldn't any fluctuations be absorbed by the charging system, not allowing the computer to cutoff or reboot since it's power supply is constant? I understand that the charger wants a pure sine wave current also but still don't see how an imperfect electrical supply would impact the electronics of the computer itself. In the inverter thread, I noticed them talking about sine wave inverters at Costco and Sam's Club for next to nothing ($40.00?), are these not truly pure power inverters? I've heard horror stories of people installing aftermarket electonics (hardwiring) into the newer cars and totally screwing up the electrical system (alarms come to mind as the most common problem) so I really want to avoid a hardwire installation. Unfortunately, Compaq doesn't show a 12V converter on their website for this laptop so I kind of think that it is out. Unfortunately, I went to the dealer to ask these questions and no one there had a clue other than to say I should have bought the model with the rear 120V outlet (which no one knew the specs of anyway).
#7
Registered User
Join Date: Jan 2003
Location: Arkansas
Posts: 228
Likes: 0
Received 0 Likes
on
0 Posts
Originally posted by Bob_98SR5
Have you decided which DC adapter you purchased?
Have you decided which DC adapter you purchased?
Trending Topics
#8
Contributing Member
Tom,
You are correct in that your laptops AC power supply takes the brunt of the abuse from the square wave power, not the laptop itself.
The battery being in-line or not really doesn't make much difference; by the time it gets through the PS to the laptop, it's DC anyway. If it's really ugly the laptop might heat up because it's not good, constant DC, but that's kind of an extreme case.
I'm just not fond of anything that makes anything (even power supplies) overheat... Means somethings ugly is going on.
If you do a web search on DC laptop power converter, you will find a couple million companies that offer computer specific DC->DC adapters. Dell (my laptop) doesn't offer one directly either.
One such (no recommendation, just first hit) might be:
here
The thing that went zot on me was the 4runners 12vdc outlet, which cut out for a while. The laptop was just warm. (Which, considering it was freezing outside the truck wasn't totally a bad thing! )
Laptop converters (I saw one I liked that had both car and airplane adapters) tend to run around $60 or $70. If you can find a true sin-wave converter for anywhere near that price, GET IT!
Or just let the beastie run warm. I've done it before, and if you're not making a huge habit of it, you'll be fine.
You are correct in that your laptops AC power supply takes the brunt of the abuse from the square wave power, not the laptop itself.
The battery being in-line or not really doesn't make much difference; by the time it gets through the PS to the laptop, it's DC anyway. If it's really ugly the laptop might heat up because it's not good, constant DC, but that's kind of an extreme case.
I'm just not fond of anything that makes anything (even power supplies) overheat... Means somethings ugly is going on.
If you do a web search on DC laptop power converter, you will find a couple million companies that offer computer specific DC->DC adapters. Dell (my laptop) doesn't offer one directly either.
One such (no recommendation, just first hit) might be:
here
The thing that went zot on me was the 4runners 12vdc outlet, which cut out for a while. The laptop was just warm. (Which, considering it was freezing outside the truck wasn't totally a bad thing! )
Laptop converters (I saw one I liked that had both car and airplane adapters) tend to run around $60 or $70. If you can find a true sin-wave converter for anywhere near that price, GET IT!
Or just let the beastie run warm. I've done it before, and if you're not making a huge habit of it, you'll be fine.
#9
Contributing Member
Most cigarette lighter fuses are 15amp, check to see what the fuse is for your outlet (I have no idea). Watts = volts × amps. For a 15amp circuit, you have 180 watts. No more. The max output of the inverter cannot be any more than the max input (it will actually be less due to various losses), 180 watts. This works out to 1.5 amps @ 120 volts.
#10
Contributing Member
Join Date: May 2002
Location: Wandering around Phoenix
Posts: 6,033
Likes: 0
Received 3 Likes
on
3 Posts
Originally posted by toy283
Most cigarette lighter fuses are 15amp, check to see what the fuse is for your outlet (I have no idea). Watts = volts × amps. For a 15amp circuit, you have 180 watts. No more. The max output of the inverter cannot be any more than the max input (it will actually be less due to various losses), 180 watts. This works out to 1.5 amps @ 120 volts.
Most cigarette lighter fuses are 15amp, check to see what the fuse is for your outlet (I have no idea). Watts = volts × amps. For a 15amp circuit, you have 180 watts. No more. The max output of the inverter cannot be any more than the max input (it will actually be less due to various losses), 180 watts. This works out to 1.5 amps @ 120 volts.
#11
Registered User
Join Date: Jan 2003
Location: Arkansas
Posts: 228
Likes: 0
Received 0 Likes
on
0 Posts
Originally posted by Robinhood150
To be more precise the inverter can be as high as you want, but the appliance used should not draw more than 180 watts.
To be more precise the inverter can be as high as you want, but the appliance used should not draw more than 180 watts.
Since I'm away from the truck, I can't say for certain, but I believe the rear power port has the same capacity as the front.
#12
Contributing Member
Originally posted by Robinhood150
To be more precise the inverter can be as high as you want, but the appliance used should not draw more than 180 watts.
To be more precise the inverter can be as high as you want, but the appliance used should not draw more than 180 watts.
#13
Registered User
Thread Starter
Join Date: Jul 2003
Location: Virginia
Posts: 97
Likes: 0
Received 0 Likes
on
0 Posts
Thanks for all the help. I think I'll got the 12VDC converter for the laptop since it's the only thing I would be running off the outlet anyway. Sounds safer and I don't want to destroy a $1500 laptop for the sake of a cheap power inverter.
Thread
Thread Starter
Forum
Replies
Last Post
icentropy
86-95 Trucks & 4Runners
7
07-14-2015 10:23 AM