Trick to using your XPS15 power adapter on airline flights!!!

For those of you who have purchased your wonderful XPS 15 in hopes of using on that next airline flight with the AC outlets under the seat will be sorely disappointed when you go to plug in the AC adapter and the little green light turns off and your adapter doesn't come on. Well there is a reason and a solution! . The Power adapter has an excessively large in-rush current when you first plug it into the wall as it charges up it's internal capacitors, this current is enough to trip the over-current protection on the outlet. The good news is that the plane outlets have a fast recovery time so here is the solution....

1. Don't plug adapter into laptop yet. Plug adaptor into outlet... the green light will go off.
2. Pull plug out just enough for light to come back on, you've now found where it makes contact.
3. push it back in just enough to make the light go off, right when the light goes off pull it back out a little bit. you will notice after a few times the little white light on the dell plug will come on, but you're not done yet because the light on the outlet will keep going off. keep doing this as fast as the little green light will let you. after about 15-20 seconds of doing this the green light on the outlet will stay on and so will your power adapter.

All done, now plug the adapter into your laptop and sit back and enjoy your fully powered notebook for the duration of your flight. For those who ask or wonder if it's overloading the outlet, no, if it was then it would shut off while you are using it. and that's why the outlet has built in protection. It may during heavy gaming but for normal usage I had absolutely no issues on 4 international flights.

 

The same can be said for my car's electrical socket. I don't notice any difference if the plug's plugged into the laptop or not. Takes about 3 tries to stay on.

 

Ahh, this is how I fixed all my tech as a kid in the 80s.

Just jiggle it.

 

Careful with that; it puts a high load on the adapter's circuit, which could kill it.

To minimise inrush-current there's a few Inrush-Current-Limiters right after the plug. These limiters are a (very large) type of negative temperature coefficient resistors;

1. While cold the ICL has a high resistance, limiting the inrush-current.
2. The input current self-heats the ICL.
3. Heat causes its resistance to drop.
4. Current charges capacitors and total circuit resistance can limits current without needing the ICL.
5. ICL is side-tracked in the circuit.
6. The bypassed ICL can now cool down for a next run.

Spoiler: inrush current

Problem here is the cool-down period:

So if the capacitors haven't been fully charged yet, then you're exposing the adapter to the full peak current (since the ICL is still hot and has near-zero resistance).

Hmm ... what if you used something like this:

Spoiler: Y splitter

Except reversed, that is; 1xF, 2xM. Use two outlets and plug both in and connect the adapter last. Divvying up the load may be sufficient to prevent triggering the outlet.

 

I'd also recommend trying a USB-C adapter. The Google 60w one is an option as its unlikely to trip the overload protection of a car or plane and could charge other devices in the future

 

Does this actually work? I posted a question about charging via usb-c on the 9550 and was told that it didn't work...or at least charging from a battery pack (like the large portable ones for cell phones) didn't work. I know dell is coming out with some battery pack but why wouldn't it work with others?

 

So far the 60w usb-c adapter from google is the only one that works with the xps 15 (that I know of anyway)
https://store.google.com/product/universal_type_c_60w_charger

 

Any USB-C charger should technically work if it complies with USB power delivery specs, but it seems as if 60 watts is the minimum the XPS will accept as a power supply. Those small battery packs and chargers for tablets/phones usually output around 2A at 5V (10 watts), and the Apple is rated at 29 W

 

Right, the apple one doesn't work on the XPS sadly.

 

Found this auto/air 65 watt adapter from Dell. The product page is a mess so I'm not really sure what it is, but it mentions USB-C charging and also claims its an AC adapter as well. Maybe its an upcoming product and they haven't fully written the device page, but might be something to keep an eye on. Price is high though
http://accessories.dell.com/sna/pro...oductdetail.aspx?c=ca&l=en&s=bsd&sku=492-BBUN

 

Thank you everyone for your input, I'm glad to see there are some alternative options and the Google one looks like a definite contender , plus its smaller and lighter than the regular adapter. Thanks t456 for your input on the inrush current details, although hopefully with the relatively low output of the airline AC outlets it wont be placing as high of a load on the limiting resistors. Had I known of the USB-C adapters I would have never had to post the thread in the first place .. now if I can just get this 9550 to run as stable as my boat anchor precision M6800 laptop I will be a happy camper.. the new drivers released on dec 21st have stopped the blue-screens and crashing but now the Wi-Fi is flakey when taken out of standby .. grrr.

 

The USB C spec allows 5V, 12V or 20V as charging voltage. It seems Dell does only support 20V, that's why only the Google adapter will work. Not sure if a later BIOS update can fix that. It looks more like Dell saved a few cent for necessary components instead of making it fully compatible.

 

Wanted to also update that the XPS 12 uses a USB-C charger supplied by Dell, which is 45 W (although that's not a USB PD spec number). That should probably work just fine but I cannot find it on Dell's site. They also have a Power Companion model that's compatible with the XPS 12 coming soon, so that may have USB-C. And their auto adapter here: http://accessories.dell.com/sna/productdetail.aspx?c=ca&l=en&s=dhs&cs=cadhs1&sku=492-bbun should work great but is expensive. Other cheaper third party options should be coming soon.

Also, I not sure Dell tried to save any money with the incompatibility as the USB-C port is the Thunderbolt 3 Alpine Ridge which is the best available. I just think Dell laptops reject any power supply that's under x watts, either USB-C or the round connector. Not entirely sure why they do this, but seems to common across

 

Sorry, but I can confirm that it is not the power but the missing voltage compatibility. For being able to use 5 or 12 V instead of 20V (the battery's own charging voltage!) they need to use voltage step-up converters - which they seem to have skipped. Apple has that in the 12" MacBook, it charges with whatever you throw at it.

 

Gotcha, but what makes you think they skipped adding any converters that Apple added?
My thought that the accept/reject determination is based upon wattage is based upon the fact that the Dell page and Intel Thunderbolt 3 graphics indicate support for USB Power Delivery, which specifies many different amp/voltage combination (I believe 6), only one or two of which are at 20 V. I agree that you need to have a voltage above the battery voltage to reverse the battery's potential (basic physics), but I don't see any evidence the needed transformers for this are not included. Hope to get more details as this makes a big difference when looking at future portable battery packs.
Does anyone know if the HP Spectre USB-C charger is accepted by the XPS 15? That does not output at 20V but was one I was considering.