20 Posts
0
6000
XPS 13 7390 2-in-1, second AC power adapter?
I want to buy second adapter with charger for my 7390 2-in-1. on the original it says 45W. which one should i buy and to what i should put attention to?
thank you
20 Posts
0
6000
I want to buy second adapter with charger for my 7390 2-in-1. on the original it says 45W. which one should i buy and to what i should put attention to?
thank you
Top
jphughan
4 Operator
4 Operator
•
14K Posts
0
November 12th, 2020 11:00
@Jungle Elephant The 7390 2-in-1 uses USB-C for charging, so any USB-C charger that offers 45W or more will be fine. But USB-C charging will only become more ubiquitous over time, you might want to make sure to maximize compatibility with other devices. So first, I would make sure that any charger you consider supports all of these voltage output levels: 5V, 9V, 12V, 15V, and 20V. Some device that supports fast charging will only do it at certain voltage levels. In that case, even if the charger supports enough total wattage, if it doesn't support providing it at the correct voltage level, the device being charged will drop to a lower level and won't charge as quickly. For example, iPhones will only fast charge at 18W if that power is provided at 9V. If the charger doesn't support 9V output, they will only use 5V, and iPhones will only draw 10W when receiving 5V power, even if the charger supports providing more power.
And then you might want to think about getting a higher wattage charger than 45W, just to cover other devices you might have now or in the future. 60W chargers aren't much larger or more expensive than 45W chargers, for example, and there is absolutely no harm using a higher wattage power source with a lower wattage device. The way USB PD works is that the charger advertises the power levels it supports, and then the device being powered gets to choose from among those options. This prevents the charger from supplying a power level the device doesn't want or can't handle, and also prevents the device from trying to draw more power than the source can provide.
And then you might want to think about a multi-port charger for additional convenience. I personally have this charger, which you can find on Amazon at least if you're in the US. The fact that uses GaN (gallium nitride) tech means that it's a lot smaller than most other 90W chargers, and I like that it both has dual ports and multiple ways of splitting power between those two ports, namely 90/0, 60/30, and 45/45. With your XPS 13, you could be charging your laptop at max performance and still have another 45W available for something else. And as you'll see, it's not even very expensive compared to Dell's own 45W USB-C charger that only offers a single port and has half the total power output.
And if you go this route of having a "wall wart" charger rather than a "brick" that sits between two cords, one thing you may want to consider getting is a longer USB-C cable. That charger comes with a 6-foot cable, but laptop power adapters often have 8-9 feet of total length. So you might want a 10-foot USB-C cable. Note that not all USB-C cables are identical. If you just want one for charging, don't worry about spending more on USB-C cables that support USB 3.x data or video. You just need a USB-C cable that supports power and USB 2.0 data speeds. The other thing to watch out for is maximum power. Most USB-C cables only support 60W (3 amps), while some support 100W (5 amps). If you have a 60W cable, you'll only get 60W. That's fine for your XPS 13 that will only draw 45W anyway, but it would make it impossible to get 90W out of a single port from that charger I linked above. Just be aware that at 10 feet, a 100W cable is noticeably thicker than a 60W cable. At 6 feet, the difference is pretty negligible, so I personally standardize on 100W cables for my 6-foot cables, but when I want 10-foot cables, I only get 100W versions if I'll be using it with a device that requires more than 60W.
jphughan
4 Operator
4 Operator
•
14K Posts
0
November 18th, 2020 06:00
@Jungle Elephant It probably only supports 5V output and then anything up to 4A. But that doesn’t necessarily mean the phone won’t support other voltage levels. I really don’t know what else to tell you about that phone since I’m not familiar with it. If you want to avoid getting the RAVPower charger because it doesn’t support a charging level used by your phone that is not allowed under the USB PD spec, then don’t get it. But if you’re willing to accept that the RAVPower charger MIGHT charge your phone more slowly but would still be a great charger for OTHER devices that rely on the actual USB PD standard, then it’s worth considering. At this point I feel like we’ve spent way too long on a discussion about a simple charger. I really don’t have any more advice or knowledge to offer here.
Jungle Elephant
20 Posts
0
November 13th, 2020 09:00
what about this one alhtough its quite espensive.
jphughan
4 Operator
4 Operator
•
14K Posts
0
November 13th, 2020 09:00
@Jungle Elephant Unfortunately I'm not familiar with the charger brands available in the EU. I know that some brands I know and trust, such as Anker, have at least some products that have removable prongs so that you can switch them for whatever is appropriate for your location, but I don't know if Anker sells in the EU. Those products might be more oriented to people in the US who might travel to the EU, since only some of Anker's products have swappable prongs.
The charger you linked seems promising, and for a 120W charger that uses GaN technology, that price doesn't seem unreasonable. The things that aren't clear from the description though are the supported voltage and wattage outputs for each port, and how flexible they are. For example, I have one multi-port charger that has a 60W USB-C port and an 18W USB-C port, and both can be used for max output simultaneously. I have another charger that has two USB-C ports and 60W total output, but it can only run 60/0 or 30/30 splits. It can't run a 45/15 split, for example, which makes it less useful with certain device combinations. I mention this because finding a 65W dual port USB-C charger does not necessarily mean it will run a 45/20 split like you want.
In terms of cables, I buy pretty much all of my cables from Anker, StarTech, and Cable Matters. If any of those brands are available in your location, I wouldn't hesitate to recommend them. Here in the US, all three of those brands make 10-foot USB-C cables that support 60W charging and basic USB 2.0 data. 10-foot USB-C cables that support 100W are harder to find, but you may not need that anyway, and if you don't I would avoid them due to thickness.
Jungle Elephant
20 Posts
0
November 13th, 2020 09:00
thank you @jphughan for your extensive respond that really helps by choosing right adapter.
I would love to order such dual wall charger you proposed with the link, but as I am from Europe, we do not have same socket as you in the US. Do you now where to look for such adapter with EU socket?
The 90W charger would be good. I just checked and found out that my phone needs 20W for fast charging and of course it uses type C connector. This means that i could use it to charge along with XPS13. Even 65W charger would be enough i think so.
Do you maybe have some links where to look for longer type C-type C cables to connect charger with xps13 or charger and phone? What cable would you suggest for the phone?
I have been looking for both sides type.c cables some time ago, but could not find.
Your help on tis would be gratefully acknowledged.
wbr
Best regrds
Jungle Elephant
20 Posts
0
November 17th, 2020 01:00
@jphughan how do you know from the description how RavPower 90W charger splits the power if 2 devices are connected simultaneously.
https://nerdtechy.com/ravpower-90w-usb-c-wall-charger-review
I have found same charger here with EU socket
https://www.amazon.de/-/en/RAVPower-Charger-Supply-MacBook-Nintendo/dp/B08CVCFVJY/ref=sr_1_8?dchild=1&keywords=ravpower&qid=1605607258&sr=8-8
is this the one I need?
I have checked my phone and its output is 5V/4A = 20W. but the charger can supply only 5V/3A, is this a problem? does it mean, that my phone will not charge, but will actually discharge?
jphughan
4 Operator
4 Operator
•
14K Posts
0
November 17th, 2020 05:00
@Jungle Elephant I know how the charger works because I own it and have verified that it will do 90/0, 60/30, and 45/45, all of which are mentioned on its product page. I even tested connecting a 45W + 65W laptop simultaneously to see if the charger would run 45/45 or 60/30, and it ran 45/45.
5V 4A would not be compliant with the current USB PD spec, which only allows up to 3A unless you’re running 20V, in which case up to 5A is permitted. It also means that getting 20W will require 5A/100W cables rather than the vastly more common 3A/60W cables. All of that is why 20W is supposed to be delivered at either 9V or 15V under the USB PD spec, either of which could be carried across standard USB-C cables. What kind of phone do you have that uses 5V 4A?
But no this does not mean your phone would discharge when connected to a different charger. It just means that it wouldn’t charge as quickly as it could — unless it also supported 20W charging at some higher voltage in a way that was complaint with USB PD. You say your phone’s output is 5V 4A, which doesn’t make sense. Do you mean your phone’s input is 5V 4A or your phone charger’s output is 5V 4A? If the phone’s input supports any other voltages, then the RAVPower charger would be able to provide them.
jphughan
4 Operator
4 Operator
•
14K Posts
0
November 17th, 2020 16:00
@Jungle Elephant Sounds like your phone and charger are using a proprietary standard to get 20W charging. I'm not familiar with that phone, so I don't know what power levels it would support via USB PD. If it supports 20W via standard USB PD levels as well, such as 9V 2.2A or 20V 1.3A (or even 20V 1A, although I doubt a smartphone would use 20V), then the RAVPower charger would be just as fast since it can handle all of those. If the phone doesn't support 20W via those options, then the question would be what power level it DOES draw from chargers that follow industry standards. I can't imagine it would refuse to charge at all, since requiring a proprietary charger would be a huge inconvenience for users, but it might charge more slowly. But in that case, the only way to maintain maximum charging speed would be to keep using chargers that support that phone's proprietary standard. Those might be tough to find, in fact that might even limit you to that vendor's specific 20W charger, which of course wouldn't be as useful to OTHER devices as this 90W charger. So if your phone only supports 20W via a proprietary standard, your options will be to either deal with slower charging from the 90W charger or to keep using the 20W charger for your phone and use the 90W charger for other things.
Jungle Elephant
20 Posts
0
November 17th, 2020 16:00
@jphughan yes my phone's (Oneplus 6T) charger output is 5V/4A. According to phone's specs, it support Fast charging 20W. Its battery: 3700 mAh (non-removable) Fast Charging (5V 4A)
will this charger then suits my phone and laptop?
Jungle Elephant
20 Posts
0
November 18th, 2020 02:00
@jphughan the output on the charger of the phone is 5V/4A, i dont know what supports else. that is all what does it says on the charger. see attachment.