Power inverter questions

[m007allred]

Hi all,
I just registered and thought i would ask a question regarding my newly purchased 1998 4runner sr5. I was looking into power inverters to run maybe two laptops, and a portable dvd player, my question is can you get a power inverter that draws too much power and would hurt the vehicle? I found an inverter on amazon that seems like a good deal, but i dont know if it would work well with my 4runner?

if someone could take a look at this and tell me whether it would work fine or it would hurt my car i greatly appreciate it!

this is the link to the inverter i was considering..
Amazon.com: Cobra CPI 480 400-Watt 12-Volt DC to 120-Volt AC Power Inverter with 5-Volt USB Output: Automotive

 

[JohnsD90]

I have a 375 or 400 watt inverter hardwired in my 4runner, costed about $10 in supplies to hardwired it, and i velcroed it to the floor under the passenger seat next to the rear heater, i would get pics but im on my phone, if you would like to see it click on the link to my 4runners fix/build thread in my signature, i posted that only a few months ago so it should be more thsn half way through the thread. I have a Husky inverter from home depot, i like it i can run atleast 1 laptop and charge a phone without the truck on and having a crappy battery in my truck...

 

[turbodudey2]

That one says it has a cig lighter plug and direct-to-battery cables.

I would just recommend not using the cig light plug to power it. At peak power out put that's drawing about 65 amps, (too much for the cig lighter)

If you hard wire it with some heavy duty cable (0-2 gauge wire) you shouldn't have any problems.

 

[Mr. Leary]

Not enough juice to run two laptops+. 400W requires lots of amperage at 12V. You should look into a 1000W inverter.

Definitely hardwire it with an inline fuse and at least 8 guage cable (recommend 4ga).

 

[JohnsD90]

Not enough juice to run two laptops+. 400W requires lots of amperage at 12V. You should look into a 1000W inverter.

Definitely hardwire it with an inline fuse and at least 8 guage cable (recommend 4ga).

I did 8 guage, and reccomend it as a minimum as well, but if the inverter has a fuse built like mine does i dont see a need in running a 2nd fuse, ive blow it before a few times but that was before i had the 4runner.

 

[Gonzo113]

I have a 600w mounted in the rear of mine. Running it off the same 4ga wire I have coming from my battery to my amp. I have used it to charge my spotlight and use it to plug my camper in the keep the fridge cold. No problems so far.

 

[Gerdo]

Not enough juice to run two laptops+. 400W requires lots of amperage at 12V. You should look into a 1000W inverter.

Definitely hardwire it with an inline fuse and at least 8 guage cable (recommend 4ga).

An apple powerbook draws 65 watts, 120 volts AC, max on startup and charging the battery. A 400w will do just fine.

Will it harm your vehicle? If you run too long with the vehicle off it will drain the battery. Do this too many times and you will kill the battery. With the vehicle running, you should be able to run a 400w at max all day long. If you are idling and have a bunch of aux lights on, then you could actually run your battery down. I have run 2000w inverters off vehicles (drawing 1500 watts) and if the vehicle was idling it would want to stall due to low voltage.

Inverters are not 100% parasitic free. They also only draw the power used (plus the parasitic draw) by the items plugged in.

 

[Swede]

Keep in mind that a "pure sine wave" type inverter is safer for your sensitive electronics than the more common and cheaper "modified sine wave" inverters are. I run a 1500 watt "modified sine wave" on my rig hooked up to my second deep cycle gel battery and have never had a problem with it running my laptop or charging my cell phone or any other equipment that I have, but the potential for damage is there though.

 

[TheDurk]

Keep in mind that a "pure sine wave" type inverter is safer for your sensitive electronics than the more common and cheaper "modified sine wave" inverters are. I run a 1500 watt "modified sine wave" on my rig hooked up to my second deep cycle gel battery and have never had a problem with it running my laptop or charging my cell phone or any other equipment that I have, but the potential for damage is there though.

Not really. Cell phones and laptops are DC beasts. That sine wave runs through a transformer in the wall wart and immediately hits a rectifier set giving DC output. You need a sine wave for induction motors (might not run), high-end audio, (possible noise), and 110V monitors (possible power artifacts). There is really no way a modified sine wave can ruin anything that runs off a wall wart unless the inverter is really producing bad output (i.e. NOT a modified sine wave but something else).

 

[Stuntmonkey]

So this seems to be the newest thread I can find on this topic (If my search skills have fail me you may proceed with the flaming).

I'm planning on picking up an inverter when I come stateside this weekend, and will probably hard wire it in. I'm thinking at least 400W, so 4GA wire and a 30A fuse should be sufficient? I'll only ever be running a macbook pro charger through it, which isn't much draw (65W I think?) but upped the fuse size in case I run something else. Am I wrong?

 

[BrianSD_42]

I have this one and am quite happy with it.


$40 Duracell DRINVP175 175-Watt Pocket Inverter with 2.1-Amp USB Port

Duracell DRINVP175 175-Watt Pocket Inverter with 2.1-Amp USB Port : Amazon.com : Automotive

 

[Swede]

Not really. Cell phones and laptops are DC beasts. That sine wave runs through a transformer in the wall wart and immediately hits a rectifier set giving DC output. You need a sine wave for induction motors (might not run), high-end audio, (possible noise), and 110V monitors (possible power artifacts). There is really no way a modified sine wave can ruin anything that runs off a wall wart unless the inverter is really producing bad output (i.e. NOT a modified sine wave but something else).

Yeah there may be some truth to that because I've never had an issue either. There is lots of information that says otherwise too so in any case they are great to have in your rig no matter what.

To respond to your question "stunt monkey", 4 awg is overkill for a 400 watt inverter. If my calculations are right you would only need to run 10 awg for a 400 watt inverter as it would only draw 33 amps max. So a 30 amp fuse would be fine too.

 

[Stuntmonkey]

Yeah I gathered, but at the moment I'm looking at a 1500w inverter from costco haha. Its the same price....so why not.

I'm going to grab a blue sea fuse block and wire that up nice and neat in the engine bay, as I'll be running some LED pods much like those that rickashay has in his trunk.

 

[Saved]

Hi all,
I just registered and thought i would ask a question regarding my newly purchased 1998 4runner sr5. I was looking into power inverters to run maybe two laptops, and a portable dvd player, my question is can you get a power inverter that draws too much power and would hurt the vehicle? I found an inverter on amazon that seems like a good deal, but i dont know if it would work well with my 4runner?

if someone could take a look at this and tell me whether it would work fine or it would hurt my car i greatly appreciate it!

this is the link to the inverter i was considering..
Amazon.com: Cobra CPI 480 400-Watt 12-Volt DC to 120-Volt AC Power Inverter with 5-Volt USB Output: Automotive

A 400 watt is not a big unit. It will draw about 33 amps at 12 volts and put out about 3 amps at 120 if fully used. Keep in mind that for every 33 amps of draw on the alternator you lose about 1HP of engine power and you also need to add in anything else you might be using at the time to be sure you are not exceeding your alternator capacity output. I highly recommend a direct battery hook up with an inline fuse and not through any existing shunt.
Now will it hurt anything? Just like any added service you will be working the alternator harder so alternator failure could be sooner then normal if you use this very often. How much sooner no one can tell you. Also if you use this with the engine off and draw down the battery and then have to recharge it you will experience battery failure sooner then regular. Other than these things I see no reason why you cannot use this unit.
I would point out one last thing. I would seriously doubt that you could run all those things you mentioned at once and even the laptop by itself is questionable as they usually draw more then this is rated for which would be about 3 amp output. Even if it works you never want to use the full capacity of a unit for very long as it causes too much heat. You should have at least a 20% reserve at all times and 50% is better. You need to check the amps needed at 120 volt to run these devices before you purchase this unit. My guess is you will need one almost three or maybe 4 times that size depending on how much you intend to run at once. Also you need to be sure your alternator will handle the added load. And finally I would suggest that since you are planning on using a laptop you get an inverter with a clean frequency (pure sine wave inverter). Computers can be harmed with an irregular wave length. They do make inverters especially for the use with computers and sensitive devices but they do cost more. You just have to decide if you want to take the chance of using an inverter not designed for computers.

 

[Marcswhite4runner]

Keep in mind that a "pure sine wave" type inverter is safer for your sensitive electronics than the more common and cheaper "modified sine wave" inverters are. I run a 1500 watt "modified sine wave" on my rig hooked up to my second deep cycle gel battery and have never had a problem with it running my laptop or charging my cell phone or any other equipment that I have, but the potential for damage is there though.

That's interesting, because that's what i'm considering at the moment. Pure sine vs Modified sine. I don't have experience with pure sine, but my modified sine was working fine before. Having said that, I wasn't trying to charge a laptop before.
https://overlandsite.com/accessories/pure-sine-wave-inverter-reviews-2018/
Doing my research because i want to make sure they're worth the extra $$$

 

[Swede]

That's interesting, because that's what i'm considering at the moment. Pure sine vs Modified sine. I don't have experience with pure sine, but my modified sine was working fine before. Having said that, I wasn't trying to charge a laptop before.
https://overlandsite.com/accessories/pure-sine-wave-inverter-reviews-2018/
Doing my research because i want to make sure they're worth the extra $$$

You can see from the picture the difference between the wave profiles of a Modified vs Pure sine wave inverter.

If you're running only resistive loads like incandescent lighting, heater, toaster etc., then modified is okay, but if you are planning to run inductive loads like HID lighting, electric motors, stereos etc., then a pure sine wave inverter is the safest way to go. BTW, I fried a cordless drills battery trying to charge it from my 1500w modified sine wave inverter.