Don’t buy a new Qi2 charger if you have these Pixel phones

Wireless charging on Pixels has been a complicated affair for years now. Oftentimes, the speeds that Google has claimed a phone can reach were only achievable through proprietary charging with the Pixel Stand 2nd Gen, leaving the phones struggling on other Qi chargers. Qi2 didn’t simplify matters either, with the Pixel 10 series adding Qi2 support but misbehaving on older Qi chargers, as reported by many users and shown in my own testing.

During my tests, I also noticed something else: My Pixel 9 Pro and Pro XL were dropping down to 5W max when charging over my new Qi2 15W and 25W chargers, even though they’re able to charge much faster on older Qi chargers. Here’s what’s happening.

The Google Pixel 9 Pro and 9 Pro XL can charge at a rate of up to 12W on older Qi wireless chargers, when those are EPP (Extended Power Profile) certified. I’ve been able to verify this on both of my SwanScout 3-in-1 chargers (10W) and my Baseus MagSafe 15W Qi power bank: In my tests, the two phones appear to draw up to 8-9W of real power, as measured in the Inware app, while charging, which lines up with the theoretical 12W of power draw.

However, when placed on a newer Qi2 15W or 25W charger, both phones dropped significantly and only showed a real battery power draw of 3.5W or so, which indicates they were throttled down to a theoretical 5W charge. That’s the lowest a Qi charger can deliver, and is referred to as the Basic Power Profile (BPP).

You can see this difference in the spreadsheet above (full Google Drive link), with the charging rate on the older Qi EPP chargers in blue versus the new Qi2 chargers in yellow. I’ve repeated this test on a few older Pixels I have at my disposal (Pixel 7 Pro, Pixel 8, Pixel 8a, Pixel 9a, and Pixel 9 Pro Fold), all of which can theoretically reach between 7.5W and 12W, and none of them were able to draw more than 3-4W from the newer Qi2 chargers, indicating a similar cap at 5W. So, what gives?

A failed handshake downgrades the Pixel 9’s wireless charging speed

Wireless charging relies on a digital handshake between the phone and the charger to negotiate speed. New Qi2 chargers prioritize the MPP (Magnetic Power Profile) protocol to deliver 15W or more, whereas the Pixel 9 Pro and Pro XL, as well as older Pixels, use the older EPP since they don’t support Qi2 or MPP. Technically, Qi2 chargers should be backwards compatible, so if they don’t detect a Qi2-certified phone, they should switch to the legacy EPP mode and deliver the full 12W to the Pixel 9 Pro and XL (or 7.5W to some other Pixels).

The theory is that something is failing in this handshake between phone and charger, and Pixels seem to reject the Qi2 charger’s negotiation to switch from MPP to EPP. Because the phone and the charger can’t agree on which standard to use, the charger defaults to the safest option, i.e., the Basic Power Profile, fixed at 5W. This is why you see the Pixel 9 Pro XL and the Pixel 9a, for example, in the screenshots below, drop to 3-4W when placed on a new Qi2 charger, even though they can theoretically negotiate up to 12W and 7.5W, respectively, on older, EPP-certified 15W Qi chargers.

Aside from this failed handshake theory, there’s also a matter of proprietary tuning and potential magnetic interference. Before the Pixel 10 series, Google was very picky with wireless charging on its phones, limiting them to a strict voltage/amperage combo during the handshake. So, if one of these parameters doesn’t match exactly with Google’s EPP parameters, which is often the case when trying to align a non-magnetic phone on a magnetic charger, the phone rejects the higher power the charger can offer and requests 5W to prevent overheating or battery damage.

If you’re looking to buy a new wireless charger for your Pixel phone, you will fall in two distinct categories:

• If you own a Pixel 10 series phone, go for certified Qi2 chargers. That’s Qi2 15W for the Pixel 10, 10 Pro, and 10 Pro Fold, or Qi2 25W chargers for the Pixel 10 Pro XL. This will get you the highest charging rates with your phone, even if you shouldn’t expect blazing speeds in reality. You’ll likely see 11-12W of real power draw on your phone most times.
  • Avoid older EPP-certified Qi chargers, even if they’re advertised to deliver 10-15W, because, as explained in my previous testing, the Pixel 10 fails to negotiate the handshake with them and defaults to 5W max instead. You’ll likely even see a slower 3-4W on your phone. So you might think you’re saving money and getting the same charging speeds on paper as a new Qi2 15W charger, but you’re not.

• If you own a Pixel 9 series phone or earlier, go for the Pixel Stand 2nd Gen if you can still find it. It’ll give you the best possible charging speed for your phone. Failing that, pick an EPP-certified Qi charger. These will likely have “MagSafe” in their name and/or advertise 10-15W of charging speed. Your phone will make the most of them within Google’s preset restrictions (usually 12W for the more expensive or newer phones and 7.5W for the others).
  • Avoid buying a newer Qi2 charger because the failed handshake means your phone will fall back to a slower 5W charging speed on it and won’t make the most of the Qi2 tech. You’re paying more money and getting worse charging. The only reason this purchase could be justified is if you plan to upgrade your phone soon, and you’re fine with the temporarily slower speeds as long as your charger is futureproof for your next purchase.

I’ll leave a couple of links to Qi and Qi2 chargers that I’ve used and liked below, but there are plenty of other options on the market, depending on whether you need a home charger or a power bank, and if you prefer a simple model or a 2-in-1 or 3-in-1 unit.