2000 Sienna max size of power inverter

What is the maximum size of a power inverter that I can use on a 2000 Sienna with a stock alternator? I have a 400 watt power inverter that I want to use to power a laptop for my daughter to watch video's on. The last thing I want to do is damage my electrical system while on the road.

Reply to
JC
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A laptop is not going to be drawing anywhere close to 400 watts. It's not the maximum capacity of the inverter that matters, its how much power you are pulling through it.

Reply to
someone

The laptop should have a label showing how much power it draws, for example,

4.5 amps at 19.5 volts. Multiply amps times volts to get watts needed to power the laptop.

Then, look at the fuse for the vehicle power socket and multiply the fuse rating, i.e., 20 amps, times 12 volts to get how many watts the power socket can supply.

If the socket can supply 240 watts and the laptop draws 100, then you're fine.

You may want to check out I-go power supplies for laptops. They are available with multiple connections so the same power supply can draw from

120 volt or 12 volts.
Reply to
Ray O

My Dell laptop is 65 watts. It worked well on an old 70w inverter I had. I got a new 150w inverter so that we could charge a couple of cell phones at the same time that we use the laptop.

Ray's suggestion to look at the fuse on the circuit you use is a good one.

Reply to
ll

The alternator should be able to handle another 400 Watts during the day with no problem, because your headlights are off. You could end up in a bit of a power deficit if you are in stop and go driving at night, with the lights on and a lot of idling - the alternator doesn't give full output unless the engine is above 1800 - 2200 RPM.

Where your problem will hit first is at the cigarette lighter socket

- don't use it. Lighter sockets are usually supplied with small wire and fused rather small, around 10 to 15 amps (140W to 210W), and that

400-watt inverter can easily draw more than that at full load. And lighter sockets have a thermal fuse inside, if you draw full power for too long you'll pop it. And the thermal fuse is not serviceable, you have to replace the whole socket.

If you have an "Accessory Power" socket in your car, great - if not, go get the kit at an auto parts store (socket, dashboard bracket, heavy wire, fuseholder and fuse, crimp terminals) and install one. They are usually designed for 25 amp (350W) or 30A (420W) loads, and they are fused, but it's a regular fuse where you can get to it.

Okay, you've installed an accessory power socket. Now that you've gone through all that - you still aren't using the right power supply device. ;-)

You have a lot of inefficiency when you turn 13.8V DC into 120V AC (one conversion loss) then the laptop power supply converts the 120V AC to 14 to 18V DC (second conversion loss). Each conversion can lose

10% to 40% of the incoming power to heat and/or transformer losses when going to AC, so that second conversion really hurts...

Go get a dedicated laptop converter from Targus, Kensington, Go Power, or the like. Make one conversion directly from the alternator's 13.8V DC to the laptop's filtered 14~18V DC.

You still need the Accessory Power socket, you'll just cut the load on it by an amp or two. And on a car, every single amp counts.

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Reply to
Bruce L. Bergman

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