The new P30 Pro, on the other hand, outputs 2.5W and when we asked Clement Wang, Huawei's VP, she mentioned it is because reverse charging is simply meant to top off accessories and that's plenty for them. Hmm, we went, let's see how that reasoning goes by testing how fast Samsung's PowerShare would work on the gizmos you are most likely to use it with.
Needless to say, The Galaxy S10e, S10, or S10+ reverse wireless is meant for charging things like the new Samsung Buds or Galaxy Watch Active on the go, rather than extending the mileage of your girlfriend's iPhone 8, but in all cases, it's nice to know that the option is there.
You won't get mAh-for-mAh transfer efficiency, of course, as some of the energy will be lost in the process, but still, the batteries of Bluetooth buds or smartwatches are so small, that the feature may actually useful without bringing you a range scare. That's especially true if you are charging from the larger Galaxy S10+ with its 4100 mAh battery pack. Or is it? Let's see what we found out.
Samsung Buds wireless charging speed via Galaxy S10's PowerShare reverse charging
In a bit over three hours, the light turned green, and the phone beeped, indicating a fully charged case. Indeed, the PowerShare stats showed 3 hours and 2 minutes for Samsung's Galaxy Buds wireless charging case to go from zero to hero. This gives you another 7 hours of listening time, says Samsung, after you charge two completely wasted Buds by placing them into their respective places in the case.
With each Bud carrying a 58 mAh battery that we drained completely, we then wanted to see how long it will take the case itself to charge Samsung's new wireless earphones to full capacity. Lo and behold, it took the case 1 hour and 17 minutes to transfer its charge to the Galaxy Buds via the cradle pins. Not too shabby, as that gives you roughly another 6 hours of listening time at mid-volume levels. The phone battery consumption during that PowerShare time was also not that terrible - the S10e pack went down about 25% in the process of completely charging the Galaxy Buds' case.
As a result, battery life isn't taking that much of a hit and we still got a day or two out of it, depending on usage intensity. How long to bring it from a dead state to a 100% charge with just your Galaxy S10's PowerShare? Well, it's again a 3+ hours affair (3 hours and 26 minutes, to be exact) despite that its battery pack is a tad smaller than that in the Buds' case.
The battery of the phone itself, however, discharged faster than when we used PowerShare to top off the earphones' case. We placed the Galaxy Watch on the back of the phone together with its straps, of course, as that's the most likely scenario someone would slap it on there to charge wirelessly. They prop it up a bit compared to the completely flat bottom of the case, hence the distance from the coil may have been slightly higher. Alternatively, the Watch may simply be able to take in electrons much faster and induce higher efficiency losses in the process.
In any case, it gobbled more than 40% of the Galaxy S10e battery for the full charge in this real-life test - phone case, Watch straps and all - as you can see from the battery discharge graph here, even though the phone showed 29% PowerShare consumption in the battery stats.
Galaxy S10 trio may be a godsend or a gimmick, as you can see from the charging speeds table. If you are commuting and forgot to top off your Galaxy Buds case, an hour on the back of the S10 will give you more than two hours of listening time.
We'd prefer more but at least your phone's battery won't be drained irreversibly (pun intended). Ditto for topping off your Galaxy Watch Active from dead state to being able to track your full weekend workout - you can but the wireless charging losses are a bit of a concern.
With more than three hours to charge the Galaxy Buds case or Watch Active completely, and unpleasant mAh-to-mAh transfer ratio, Samsung's PowerShare arrangement seems good for what it says on the tin - emergency situations when charging speeds and efficiency won't be that much of a concern, compared to pouring some much-needed juice into our irreplaceable accessories.