New power supply has 65W?

[fry]

Hi!

Just noticed that MS lists a new SP4 power supply rated at 65W.
However, all the reviews I saw rated the included power supply at 36W.

Since the SP4 should not consume significally more power than the old one the only reason to increase the output would be faster charging. But the reviews state that the required time is about the same as on the old one.

There has to be an advantage in providing almost twice the power. So either it can charge faster under full load (which would be possible due to better cooling) or the reviewers still got the old model (in which case one could expect faster charge times).

What do you think?

S.

 

[Johnny365]

It's mainly for the Surface Book, which also works on SP3/SP4. The 65w doesn't provide any decrease in charging times on the SP4 though.

 

[starstreak]

So someone tried that? Used the 65w PS on the SP4 and it charged at same speed? I know MS can take more of my money if it did charge faster.

 

[Mike007]

Just purchased a 65w supply for my SP4 i7 and it is a night and day difference in charging times between the old 36w and the new one only when the device is loaded.

The old 36w would not charge the surface at all when it was stressed and even uses the battery whilst it was plugged in.

The new 65w keeps charging the device under full load. so in a way, yes, it does charge the device faster but only when the device is under load. If the device is idling or doing light tasks then the charge rate is the same as the old one.

 

[hughlle]

I think there was probably something wrong with your old one then. Because mine has no trouble charging the device properly regardless of what the surface is being used for.

From anandtech: "I recorded a 158-minute charge time with the standard charger. Microsoft also offers a higher wattage 60 W version for use with the Surface Book, and you can also purchase it as an accessory for the Surface Pro 4. The result with that charger? 158 minutes. The Surface Pro 4 did not dump any extra power to the battery at all with the higher wattage charger."

 

[Mike007]

I think there was probably something wrong with your old one then. Because mine has no trouble charging the device properly regardless of what the surface is being used for.

I thought the same thing when I first found out about the issue so I tried a friends 36w Sp3 adapter and it had the same issue.

Several other people on various forums have had the same issue.

Also, scroll down to the stress test part on notebookcheck:

Face Off: Microsoft Surface Pro 4 Core i7 vs. Surface Pro 4 Core i5 vs. Surface Pro 4 Core m3

They report it on there.

 

[hughlle]

I sometimes see plugged in not charging, but I think that's just a software problem. From sp3 to sp4 I have never had an issue with charging regardless of usage, and a host of items plugged into a usb hub. The only time i've had a charging discharge etc is with the s3, because of the decision to go with micro usb.

Personally, i would just get on live chat with MS and explain the situation and you'll have a brand new one in the post free of charge, no questions asked, no request to return the old one.

 

[Mike007]

I have just done a quick test and started a 1080p video encode to max out the i7 CPU on battery.

This is the current discharge rate:


No wonder the 36w power supply cannot keep up. It is using over 10w more than it can supply.

Plug in the 36w adapter and sure enough it drains at -10000mW under the test

Plug in the 65w adapter and it CHARGES at 15000mW under the test

 

[Compusmurf]

In addition to your findings.... If you use the SP3 dock, it has a 46W (I think) power supply. It still exhibits slight drain under huge loads, but not as bad as the 36W power supply. The new dock has a HUGE power supply. I think it was mentioned around 9xW, and of course, that power supply connector is not the same as the sp3 dock.

Generally speaking tho, the 36W stock supply should be quite fine as most folks will never max their CPU/GPU full time, all the time. That being said, I have the 65W and the 36W for travel

 

[GreyFox7]

Unless you do a significant amount of very heavy processing the higher power charger would likely not be worth the cost. It wont actually charge the battery faster just that in the case of heavy load it wont discharge while running.