nkedel

Dell 90W adapters have always worked fine on airplanes for me, and with a beast like the 7510, I'd recommend going with the 90W.

As for models, they've been using the same power supply voltage and the 7.4mm connector for most of their models since about 2004, so there are a TON of options out there, all functionally identical

The only thing to watch for is that newer Dell power supplies come in a both the regular connector (7.4mm) and a mini one (4.5mm). They're electrically compatible, and the adapter to go from big to small is passive. Here's an example of an adapter: http://amzn.to/2sOVoQM (the 4.5mm connector is a little long, and protrudes, but it works fine.)

I'm pretty sure the 7510 takes the bigger one. There's no adapter that I'm aware of to go from a 4.5mm brick back to a 7.4mm machine.

The standard Dell 7.4mm connector supplies:
* 65W are called "PA-12" series
Current model: http://accessories.us.dell.com/sna/p...6&sku=332-1674
(plenty of different models: ex newer one: http://amzn.to/2sOC8mt slightly older model http://amzn.to/2ri2dsd older still http://amzn.to/2sODSfN , these go back to 2004)

* 90W are called "PA-10" series (plenty of different models - current from Dell
http://www.dell.com/en-us/shop/dell-...pc-accessories
(have to love the amazingly long list of compatible models!)
http://amzn.to/2s9mkwO http://amzn.to/2rNlPYR http://amzn.to/2s9r85y )

* 130W are called "PA-4E" series
http://www.dell.com/en-us/shop/accessories/apd/331-5817
(There's an old rounded one that's quite rare, but basically just the one model:
http://amzn.to/2s9g8oD ) Not to be confused with the new fairly common 130W slim one with the 4.5mm connector

They also make 180W and 240W. I think the 7510 runs standard with the 180W?

Some examples of the 4.5mm adapters to avoid:
http://www.dell.com/en-us/shop/dell-...pc-accessories
http://amzn.to/2s8Uyk3
http://amzn.to/2s9kwnp
http://amzn.to/2sP2oNx
Note that these don't use the PA-10 / PA-12 model numbering, so if you stick to that, you should be fine. The 90W 4.5mm adapter is quite rare compared to the 65W and 130W so it's least likely to be a problem at that wattage.

As discussed above, don't expect the same performance on 65W or 90W that you'd have on a regular adapter, but it's better than nothing. Jackal's experience has been better than mine with the M4700/M3800/M5510 and now an XPS 15 9560 (basically the same as the M5520) so ymmv.

There's also a 90W auto/air DC adapter:
http://accessories.us.dell.com/sna/p...p&sku=330-8105