NA — Power Inverters / Laptop Charging

[JGoodish]

Does anyone have a better solution for laptop charging in the plane/car than using a power inverter and the standard laptop charging brick? I know that this is not very efficient, but seems to be an easier solution than trying to match voltage and plugs to go DC->DC. Thinking of buying a small pure sine wave inverter which I could plug into the (12V) cigarette lighter. This would be used primarily in my wife's car, which does not have a factory-installed inverter.

My F-150 has a factory-installed inverter, but it is a modified sine wave and makes my laptop power brick buzz loud enough for me to hear, and I have congenital hearing loss. Plugged into utility power, the power brick is silent, so I'm not sure how healthy the modified sine wave is for it.

Any thoughts on this are appreciated!

 

[schmookeeg]

A laptop that charges over USB-C PD and matching PD cigar lighter adapter?

 

[asicer]

A laptop that charges over USB-C PD and matching PD cigar lighter adapter?

That would be my suggestion as well. The only thing I have to add is to look for "Thunderbolt 3" or 4 in the spec sheet to be at least somewhat assured of that capability.

 

[JGoodish]

A laptop that charges over USB-C PD and matching PD cigar lighter adapter?

This would seem to be the best DC->DC option, but I had concerns about how much power it would supply. I see some with 60W claims, but many are around half of that, which may not be sufficient to power my MacBook Pro 16 while in use. Suppose I could give it a try.

An inverter may provide more flexibility, but I don't think I've ever plugged anything but a laptop into the one in my F-150.

 

[schmookeeg]

Does it need to be ship power? If you're running a MBP, yeah, 30W won't cut it. Get a battery bank that can push 60W PD and then you can charge it at 30W and be content you won't be blowing aircraft breakers out

I use this guy:

https://us.anker.com/products/b1290

Bestbuy has them on sale periodically. I think I grabbed it for 70 or 80 bucks.

Also doubles as a blackjack if you find yourself in a dark alleyway with some crims. It's gotta be 6 pounds or so. It'd leave a skull dent if you needed it to.

 

[wsuffa]

Targus used to make an adapter that worked with either AC mains, a cigarette lighter (12 v) or the EmPower systems on airliners. Came with a variety of plugs to use with different laptops. I had one for the old WinXP based tablet that I used in the plane before Apple came out with the iPad.

 

[JGoodish]

I’d prefer it to be ship power because I forget to charge power banks (and laptops, which is the reason for the need.)

I’ll probably give one of the “60W” USB-C PD adapters a try, and if that doesn’t work I can fall back to the inverter. I know the losses with an inverter are large and RFI is a risk so it probably doesn’t make sense if there’s a better solution.

 

[Albany Tom]

If you want to power/charge a laptop from 12v, I think you have two reasonable options. One is to get a small laptop/chromebook that charges directly from usb-c and then use a 12v to usb-c charger. That likely won't charge as fast as an ac charger, but it should keep it running. Second is to get a small sine wave inverter. I'd get one that's maybe 50%-80% over the actual draw of the charger, because typically inverters will run most efficiently at 50-90% or so of max continuous output. All these inverters are dc-dc converters running at high frequency (well, higher than 60Hz), and they're probably in the 80-90% efficiency range. So connecting two in a row isn't all that bad. The thing you want to avoid is having two cheap ones in a row, because they might start to do weird resonance things, as you noticed with the one in your truck and the ac adapter. We used to use 150 or 300W sine wave inverters for an agency I worked at, to charge laptops while mobile. Worked great. Any of them, including 12v-usb, could cause RFI in the plane, so check your nav/com/adf for interference.

 

[JGoodish]

Thanks everyone for the feedback.

Since my laptops (MacBook Pro 13 & 16) charge via USB-C, I decided to try a higher-output USB PD lighter adapter. I purchased one with 30W PD output and one with 36W PD output, and both of them will simultaneously power and charge even the larger laptop during normal use, but the chargers do get hot to the touch (almost too hot to handle). If you go this route, ensure that the PD port itself is capable of the desired rated output, as many adapters will list a total output between multiple ports (eg. 36W output, but split 18W between 2 ports.)

Note also that by “normal use” I mean general business applications and tasks, not 3D rendering or gaming which would cause the fans to spin. I suspect in cases where a higher power draw is required, the adapters would not be adequate to maintain power level.

Regarding inverters, while they are more versatile, it seems that they may not provide much benefit in my use case. Most pure sine wave inverters start at 300W output levels, which would require input power beyond what most automotive lighter outlets can provide (at higher output power draws from the inverter). If I had an older laptop or device which couldn’t be charged via USB PD, this would perhaps be the best solution.

 

[kshaw]

Harbor Freight just announced sale of a Jackery 293 wh power pack with built in sine wave AC power. I plan to get one for Oshkosh and Sun n Fun camping. Price was $199.

 

[JGoodish]

Harbor Freight just announced sale of a Jackery 293 wh power pack with built in sine wave AC power. I plan to get one for Oshkosh and Sun n Fun camping. Price was $199.

Jackery makes a nice unit. It's a great choice for off-grid or where continuous power is necessary.