Power converter for laptop use...bad for alternator??
 

Me and my fiance are driving from las vegas, nv - washington dc - northern michigan - and back to las vegas, total of about 5400 miles. i got the bright idea to try and bring our laptop to watch movies and kill some of the time. a buddy of mine recommended the:

PHILIPS GEMINI 80W POWER INVERTER
http://www.walmart.com/catalog/produ...uct_id=5720952

but...i've heard that the use of this and the load it would put on the car could cause the alternator to run c[FONT='Calibri','sans-serif']ontinuously, eventually causing it to fail. [/FONT]

the inverter is an 80W inverter and the adapter for my computer is a 65W, so i'm not gonna be maxing it out, however, are there any unwanted side effects i should be concerned about??? i'm not super mechanically inclined to know what effect prolonged use of this could have on the car or it's electrical system. also, will the additional load of this have any effect on my FE?? thanks for the help...

Re: Power converter for laptop use...bad for alternator??
 

I've never heard of these things killing alternators before, and I'd be rather skeptical of the claim anyways, given that your alternator runs whenever the serpentine belt is moving (which it always does, with the exception of AS). I've been using a 75W inverter when I drive between CBus and CTown, and haven't had any troubles.

Re: Power converter for laptop use...bad for alternator??
 

yeah, i didn't know, don't know that much about the electrical system and hearing that it could kill the alternator durring out cross country trip had me kinda worried...thanks...

Re: Power converter for laptop use...bad for alternator??
 

03 civic hybrids don't have an alternator. The 12V is charged from the hybrid battery. You are probably going to be fine. You are only going to be drawing about 6 amps I think. If you plug it into the cigarette lighter I think the fuse is a 10A fuse.

Re: Power converter for laptop use...bad for alternator??
 

Just a word of warning, I work on big trucks and have seen a couple of fires started by the combination of these and laptop batteries. You should be able to run it with no problem but most laptops throw a lot of heat if the computer is sitting on combustible material with no air flow just watch the heat build up.

Re: Power converter for laptop use...bad for alternator??
 

Thanks for the info, we had not planned any prolonged use, just wanted to be able to watch a movie or two durring our many days of driving, so it will mostly consist of watching a movie here and there, not one after another for hours on end. thanks again.

Re: Power converter for laptop use...bad for alternator??
 

If your laptop is maxing out the power supply, it will draw just over half an amp (NOT 6, the inverter output is 120 v so 65/120=.54 amps) and the inverter is not 100% efficient, so you may draw a bit more than that. Even if it were a full amp, or even two or three, it should be no problem at all. Most cigarette lighters circuits are fused at 30 amps, though a constant draw of 30 amps might get problematic. The inverter pictured has a red fuse in it, which is 10A. My only potential concern is that some electronics don't like to be run off inverters, but your power supply will probably be fine. I've run mine off an inverter before with no troubles.

However, cheap inverters can be really frustrating. They often just don't work at all because they can't handle the advertised load, or break easily. That one you linked to looks like a really tiny and cheap inverter, though phillips is not usually a cheapo brand. I have not tried one like that, but the larger cheapo ones I have used have really sucked. Plus for 12 bucks I can't imagine they used very good electronics in it, so I don't think I'd want to run my computer on it. If you can spend a little more money you'll be much better off. I would highly recommend one that's a little higher power rating (try to double your actual load, so go for 125w or so) and get something reputable if you can find it.

Tripp-Lite units are great but probably more expensive than you'll find at walmart. I got a pretty decent coleman inverter at target on sale for $30 and it was 200w I think. It has a metal case and external heat sinks so it can actually put out what it says--even though coleman is not a brand I necessarily associate with good electronics, camping lanterns and coolers sure, but electronics? I was surprised.

Also nowadays, many computer makers have a laptop power supply that can plug into the cigarette lighter directly. These usually also come with the airplane adaptor. That's another option, but it will be specific to the computer so you couldn't run other accessories off it like you can with an inverter.

Good luck.

Re: Power converter for laptop use...bad for alternator??
 

Wrong. You forget that while 60W @ 120V = 0.5A, the lighter socket only provides 12V. 60W / 12V = 5A. Constant power requires higher current at lower voltage.

Re: Power converter for laptop use...bad for alternator??
 

I think that the only poor effect would be that your IMA battery would need to charge your 12V battery a little, and you would have a slightly smaller amount of battery to assist. I don't think it would make a noticeable impact on FE tho. However, I think that your biggest danger is watching movies while driving.

Re: Power converter for laptop use...bad for alternator??
 

Yes of course. I had a momentary brain fart thinking that the current would be constant rather than the power. I am an electrical engineer after all, you might think I could get that one right.

Re: Power converter for laptop use...bad for alternator??
 

Ah, the 1/2 amp is on the output side of the inverter. The input side will draw 6 or 7 amps at 12 volts (6 amps X 13.5 volts) = 81 watts.

Re: Power converter for laptop use...bad for alternator??
 

Not the one in my 03' civic hybrid. I think it was rated at 10A or something. Maybe 15, but I don't think it was that high.

Re: Power converter for laptop use...bad for alternator??
 

It may be rated that way, but ten bucks says it has a 30A fuse in it. It's pretty common anyway.

Re: Power converter for laptop use...bad for alternator??
 

I've replaced it. It isn't 30A.

Re: Power converter for laptop use...bad for alternator??
 

I always thought the majority of auto cigarette lighters used 10A fuses.
The auto manufacturers don't want you using a giant DC/AC converter and then plugging in something huge, like a portable air conditioner :P
THAT could kill an alternator or battery.

Re: Power converter for laptop use...bad for alternator??
 

Geez, I've just seen a lot of them with 30 A fuses, that's all. Yours may or may not be 30 A.

Re: Power converter for laptop use...bad for alternator??
 

i'll check what amp fuse it is and see. If it is only 10A is there any issues with dropping in a 30A fuse or will a 30A fuse even fit in that slot? thanks for all the great info.

Re: Power converter for laptop use...bad for alternator??
 

Yes there are definitely issues with that. If it's designed for 10A then the wire and other components used are probably designed for 10A. You need a 10ga wire for 30A and if yours is fused lower it probably has smaller wire. Stepping up the fuse is a definite fire hazard.

Re: Power converter for laptop use...bad for alternator??
 

There's a universal notebook and cell phone power adapter called the iGo Juice, which has a cigarette-lighter plug in option, in addition to adapters that plug into standard home outlets and those that plug into first-class airplane seats. It fits most notebooks.

I have one at home, but I've never used it in my car to power my notebook. It might be safer to use than a power converter? But it will cost you around $90 without shipping or tax on Amazon.com.

Amazon.com listing ($90.11 on sale)
iGo Store listing ($119.99 list price)

Just a thought.

Re: Power converter for laptop use...bad for alternator??
 

For future reference, on the question of the alternator (if you were driving a car that had one) burning out because it's "running continuously": alternators *always* run continuously, at a higher voltage than the 12v storage battery -- typically 14.4 volts. The alternator always supplies all power to the car while the engine is running, unless demand rises above the alternators rated amperage, in which case voltage will sag (voltage varies inversely with amperage for a given watt output) down to the battery's 12v level, where the battery will then contribute additional amperage. If you were to do that all the time, you'd burn up both the alternator and the battery quicker. But you'd also notice things like dimmer-than-normal headlights.

But your standard cigarette lighter inverter (max 15 amp draw) isn't nearly enough load to even mildly trouble an alternator or an IMA unless you were simultaneously running headlights, wipers, both engine cooling fans, A/C, and heater blower. (And the IMA runs so much voltage it won't notice it even then.) And, in turn, a laptop power supply shouldn't overly tax a 15 amp inverter.

So, I wouldn't worry about it, and I doubt very much you'll see any change in FE from using it -- certainly no more than you see when you turn on your parking lights, because that's about the equivalent amp draw.

cheers --
doug

Re: Power converter for laptop use...bad for alternator??
 

i really appreciate all the advice and info. thanks so much.

Re: Power converter for laptop use...bad for alternator??
 

I've been using a cheapo $15 power inverter with my laptop. I bought a Garmin laptop GPS reciever for it that came with Delorme Atlas. It is basically a $100-400 GPS thingy but I only paid $60 for this thingy (Not counting the laptop of course.) I also have a 15.4'' screen :) Most of those GPS things are like 3''...

Anyways, my laptop PS says 65W also, and its been working fine. Whenever I get up to 7 bars of charge I turn the inverter to charge my laptop's battery on until I go down to 6. I have a 5 hour battery on my laptop so it's only really an issue on long trips. I figure it's not much draw, but if I'm at 7 then I might as charge my laptop. I don't know if this is a bad idea, but it's what I've been doing.

Re: Power converter for laptop use...bad for alternator??
 

I use one all the time. Running your car wears it out - big deal, that's what it's for. Having your headlights on pulss more juice too. Forget about it, use your car as you want to, and enjoy. Worry shortens life too. ;)