12VDC to 110VAC inverters, anyone use them?

I have a 400 Watt inverter wired directly (and fused!) to my Optima 12V. I found that in all of my Toyotas, not just the Prius, that the cigarette lighter/power socket fuse tended to blow from initial inrush current when turning on the inverter, even though the steady-state usage (120W) was well within the current rating of the power port. Make sure also that your inverter can run your laptop charger, as many are in excess of 100W.

 

Yes, I use one like that to charge electronic toys. I have a much larger one permanently installed on our boat. That one can power the microwave and run power tools.

Tom

 

http://priuschat.com/forums/gen-iii-2010-prius-audio-electronics/84711-installed-inverter-400w.html

 

Also keep in mind that although a laptop charger (or various other things, such as fluorescent lamps, anything with a motor, etc.) may be well under the 120W max for the port (or well under the rating for the inverter), they often have some inductive or capacitive load to them. The effect of this is that although the charger might only use 100 Watts, it needs something rated for 150 Watts or more.

Trying to explain this for those who aren't familiar with the concept of "power factor" or "reactive power"; basically, the extra 50 Watts is temporarily transferred to the charger or other device where it is stored briefly (as an electric field in a capacitor or as a magnetic field in an inductor) before getting sent back to the car. This process repeats at whatever frequency the AC runs; so in the US, 120 Hz. As a result, the components of the power supply system have to be able to handle transmitting 150 W, even though some of it isn't being used.

Practically, I found that my (dirt-cheap low-quality) 400W inverter in a previous vehicle would trip the over-current sensor if I had two Apple PowerBooks connected to it and one was charging its battery (both adapters rated at 65 Watts, which is what they used to charge, but used closer to 20-30 W when not charging). My mom's Dell laptop had an adapter rated for 120 Watts, and could never run off that inverter. So my brother and I either had to alternate who used the inverter when charging, or we had to pull out the laptop's battery so that it wouldn't charge - but then you risk losing power. Clearly, this inverter was not as good as the marketing materials on the box would indicate, even if you take into account the reactive power!

 

I have one of the "cup holder" ones that just sticks into the rear seat cupholder (whichever of the 2 you feel like sitting it in), and then it is run to the power outlet/cigarette lighter outlet under the center armrest. I can plug a number of things to it, plus it has a usb outlet. I wasn't crazy about it though, cause it had a fan that ran inside it that was incredibly noisy. And, I was running audio out of the computer thru my car stereo and it created a HORRIBLE noise through the speakers... So, I Googled that problem for a number of days, and I finally came up with this solution: DC-DC-90W - 90 Watt Car Adapter

I bought it, and all my problems were solved. Since then, I bought a 1,000 watt Duralast inverter that I will have hardwired to the car by my stereo dude. I've had the Duralast for about 2 months now, but just haven't been able to get the amount of time away from my grandmother to spend at the shop getting it installed...