Swift 3 (SF314-57G-78U6) charging very slowly via Dell WD19S 180W dock

CH0602
CH0602 Member Posts: 4 New User
Hi everyone,

I've had a Dell WD19S dock as noted in the question since Sunday, and have been using it with my Swift 3 via USB-C/Thunderbolt and until today haven't noticed an issue charging. I'm currently sat here at the desk using the dock and the charging is abysmally slow, it's gained about 1% in the last 10 minutes. I've closed all other applications than Chrome and it's still the same.

As far as I know this hasn't been an issue until just now, and the dock is charging my HP ProBook 450 G6 I use for work at a much better rate. To the best of my knowledge, the wattage of the dock should be more than sufficient to deliver a fast enough charge to my Swift 3, but for some reason this doesn't seem to be the case.

Can anyone offer any insight?

Cheers.

Answers

  • CH0602
    CH0602 Member Posts: 4 New User
    I should add, I use the laptop for some light gaming (Football Manager) so the battery is draining quicker in the first place, but surely it should be charging faster than this? 180W, even if it's only delivering 90W, should more than enough to charge the Swift 3?
  • CH0602
    CH0602 Member Posts: 4 New User
    Sorry just further to this - I've since discovered that the SF314-57G has a "Maximum Power Supply Wattage" of 65W; if my dock is supplying more power to than this via USB-C, could this be why charging is so slow? I'd have expected that if the dock power supply was lower, not higher, but could be something...
  • billsey
    billsey ACE Posts: 34,932 Trailblazer
    Nope, it's likely the other way around. I don't see real specs on the Dell dock, but it might be proving a lower voltage, even at the higher wattage, than expected. USB-C charging is often specced at 5V, 9V, 15V, 20V with an amperage for each (3A, 3A, 3A and 3.25A). 65W is 3.25A at 20V. Lower voltages are typically rated at 3A, so with 15V you get 45W, at 9V it's 27W and at 5V it's 15W. That means that if the Dell dock is putting out less than 20V it'll be slow charging due to the under 65W needs of the laptop.
    The laptop pulls 65W max, so if you had a larger charger, such as 100W, it would still only pull the 65W needed.

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  • CH0602
    CH0602 Member Posts: 4 New User
    Thanks for your reply. 

    The dock should be providing 180W, so more than enough for the laptop to pull the 65W that's needed. Is there any way to check what the laptop is actually pulling from the dock, and/or what the dock is actually outputting to it? It's so confusing to me as it's working fine with my work HP laptop.
  • billsey
    billsey ACE Posts: 34,932 Trailblazer
    The only way to tell for sure what's going on is to use a VOM to check the voltages during charging. If you aren't seeing 20V then that's the issue. It's a lot tougher to check amperage, but the assumption is that they'll be fine since the laptop doesn't pull more than the 65W level.
    Click on "Like" if you find my answer useful or click on "Yes" if it answers your question.