S25+/U problematic 15v PD profile

[arianwen27]

This is going to be quite wordy, so bear with me.

The s25 plus and ultra support 2 charge modes. 10v 4.5a and 15v 3a. The s24 series only supported 10v.

Now, a usb cable is either normal or rated for 5a. To charge a phone at the full speed, you use a 5a cable, causing the phone to charge at 10v 4.5a 45w.

With the s25 series, you can use a normal non 5a cable, the phone will then swap to 15v 3a mode. Charging at 45w but with less amps. 

With that said, there is an issue with this system. For me personally, the 15v 3a mode never enables. I have to use a 5a rated cable to charge at 45w. This can be checked as 45w says super fast charging 2.0. Otherwise it says super fast charging (no 2.0). My charger isn't by samsung but it supports everything required for these things to work correctly.

Meaning if I don't have a large 5a cable, I cannot charge at 45w, a feature the s25 series should have.

You'd expect this to be a single device issue a shop can fix. Many other people have reported the exact same issue. Samsung italy officially said they knew there was an issue but the other way round. They found issues with devices using 5a cables and says not to use them till the issue is fixed.

To to sum things up. The s25 series can charge at 45w with a non 5a cable. But for me and many other people, this is not possible and a 5a cable is required.

An official charger shouldn't be required as this whole thing uses an open standard. But I'm not buying a second charger to test it.

Kinda curious how it works with others. Get your 45w charger, charge using a normal thin cable, than a 5a cable. Does the phone say super fast charging 2.0 both times and which charger are you using?

The cable that came with your phone is a non 5a cable

[arianwen27]

Though there's little update, the charge time hasn't changed in my tests. A 5A cable shows 2.0 at 1 hour 10 minutes. A normal cable shows no 2.0 but also 1 hour 10 minutes.

I connected a wattmeter to my charger. It does in fact draw more watts when my phone says 2.0. So it's not just a graphical issue; the charge estimation page is wrong.

[Joeeye]

Ironically, my 3rd party chargers work better with my S25 Ultra than my official 45W Samsung charger. My multi port 150W charger works with any cable, 3A or 5A to charge my S25 Ultra at 45W. The official charger does as well, though I found it charging a little slower overall (probably due to its age). I actually have 3 45W chargers, 2 of which are 3rd party, but all charge my S25 Ultra at 45W.

Just a word on charging, be aware that very cold temperatures affect charging speed and even though the Superfast charging 2.0 may show, your device will not charge at full speed.

[arianwen27]

Mhm, full 45w charging also only works under 30% battery. Over that you get maybe 35w.

My 5a cable has an in line volt amp and watt meter so I can watch how the phone reacts to certain charge levels and conditions. Just a shame I don't have the same in a 3a cable format

[Joeeye]

Yeah I have a cable with a current display showing me the W. I also see 45W drops off around 30%, but I've never seen any other Samsung phone or tablet reach 45W during charging. So whatever Samsung changed with the S25 series, it's a first.

[arianwen27]

Update time. I tested an Anker power bank a friend had that happened to support all the protocols needed for Super Fast Charging 2.0. My phone was able to use 2.0 while using a 3A cable. The issue is my 120W Anker power brick; that's the reason I don't have 2.0 using a 3A cable.

[heavylynx]

I have been testing charging speed of my s25 ultra from last couple of days: always from 5-100%, at the beginning it always says Superfast charging 2.0 and 66min to full charge, below are the actual charging times-
Anker 45w + 3A: 65 mins
Samsung 45w + 3A: 70 mins
Anker/Samsung 45w + 5A: 75 mins

It never charged under an hour and it's from 5%, 65 mins is still acceptable but 75 min with 5A cable is almost 25% more time than what it should be.

[arianwen27]

Makes sense with the 3a vs 5a. A 3a cable causes a lower amperage to be used, causing less heat. Less heat means the battery can handle more sustained charging. Same power output but less heat is produced.

Haven't done testing on this but I believe under 10% charges considerably more slowly to protect the battery. From 10-30% you get the full thing. Then from 30-80% you get maybe 35w. Over 80% it'll probably slow down again as it hits the cap. 90% and higher will be very slow as the battery peaks

[heavylynx]

True, I have setup custom notification to track the charging speed and I can see that it slows down quite a bit when it goes above 80%.
Samsung 45w + 3A: Total 70min
5-50% : 25 min
50-80% : 24 min
80-90% : 7 min
90-100% : 14 min

90-100% is extremely slow and I believe not very good for long term battery health as well.

[arianwen27]

Yeah, lithium batteries hate being at or near 100% charge. Ideally, they should be kept between 40% and 80%. That's unreasonable for a smart phone of course.

Samsung has a really nice feature for this, battery protection. When the phone hits 100%, it stops charging till it goes to 95%, then goes back up to 100% and loops. This stops the battery being constantly maxed out.

For real care, adaptive or max are best. Adaptive keeps the phone at 80% as you sleep, then goes to 100% for exactly when you wake up. If it's too early, it does the loop thing.

When I use waze in my car, I have an 80% cap auto enable so my car charger doesn't destroy my battery.

At night, I use standard wireless charging. So 5w wireless charging. Takes maybe 5 hours to fully charge the battery but as it's over night, not an issue. Since the charge is so slow, the battery benefits greatly from it. Fast charging always harms the battery a little

[arianwen27]

Update time; this is becoming a trend, but it should be the last time.

I managed to get an official 45W charger for £9. Official website, deals and codes.

It does, in fact, supercharge 2.0 with both 5A and 3A cables. Of note, 5A cables still use 10V to charge, meaning it is technically less efficient to use a 5A cable compared to a 3A cable.

Also, there is something else Samsung is doing. Using my Anker charger and a 5A cable, I get Super Fast Charging 2.0, and non-2.0 with a 3A cable. But the charge icon is green.

When using this new official charger, the charge icon is blue.

So it charges using the same Super Fast Charge version, but the phone can obviously detect the difference, as the colour changes from green to blue with the official charger.

Extra side note, samsung ai spell check spells colour the american way