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I have an S21 Ultra and I also have one of the original Samsung Wireless Charger units.
When I plug the charger in, in lights up.
When I place my S21 Ultra on the device, it states "wireless charging" and a time of up to 4.5 hours.
Left it on charge overnight, S21 Ultra became rather warm but device picked up no charge overnight.
Does the S21 Ultra work on older wireless chargers? I've set the Faster Wireless Charging to on.
Are you using an official Samsung fast charging plug along with the wireless charging unit ?
I appreciate one does not come with the phone and some Samsung wireless chargers don't come with them too.
If you've bought one did you buy it from Samsung ?
Sometimes if the phone isn't placed just right on the charging stand it can glitch and not charge properly.
Also if you have a case on the phone then depending which one it is then it maybe beneficial to remove it while charging.
I use several types of Samsung wireless pads and desk top stands along with a duo Samsung charger and they all charge up several phone's I and my family use so yours should be good to go.
My son charges his Samsung Galaxy s21 Ultra on mine too. He turns on fast and super fast charging on in his phone's settings and off it goes.
A phone will naturally warm up when charging and sometimes even more so when fast or super fast charging.
Most of my Samsung Wireless chargers also have inbuilt fans to help keep the phone cooler.
Current Phone >
Samsung Z Fold³ 5G.
Previous Phone >
Samsung Note 20 Ultra 5G - SM9860.
Thank you for your reply.
The unit is genuine Samsung but is a few years old, the Samsung plugs (I have a few and only genuine ones) were bought this year.
Placement was fine, the S21 Ultra said it was wireless charging.
I'm wondering if it is simply because the wireless charger is so old? Do I need a more modern one perhaps?