Price (RRP): $99.95
The Belkin BOOST↑CHARGE Power Bank 2K for Apple Watch (all series) is exactly what it says – a Qi wireless charger and power bank for an Apple Watch.
Design-wise the BOOST↑CHARGE Power Bank 2K is about the size of a matchbox (79 x 42 x 17mm x 70g) in basic black with a white concave magnetic charge plate. On one end is a micro-USB socket for 5V/2.1A (maximum) charging and four LEDs to approximately indicate 25% increments of charge.
Under the bonnet, it is a 3.83V, 8426Wh, 2200mAh battery which is to power the 200-300mAh (approx) Apple Watch battery. The Qi charge plate outputs 5V/1A or 5W.
BOOST CHARGE Power Bank 2K for Apple Watch Model F8J233btBLK
Australian website here
Charging the power bank
It came indicating 75% charge, so we set about topping the rest up. No charger comes with it, but a 180mm short USB-A to micro-USB cable is in the box. Using a 5V/2A charger it took over an hour indicating a full charge at around four hours.
In one further subsequent test from almost 0-100%, it took just over five hours. This is slower than expected.
We would love to say that a 5W (5V/1A) Qi charger works as fast as a 5W wall charger but by it nature Qi seldom achieves over 70%
As a control, we ran down an Apple Watch 4 (easy to do if you use GPS) and charged from its genuine charger cable/plate – time just over two hours.
Rinse and repeat. We used the charged BOOST↑CHARGE Power Bank 2K, and it took nearly four hours. This indicated closer to 50% efficiency. Had it achieved 70% efficiency, this should have been closer to three hours.
We tested a further two times – 0-100% and the best was 3.5 hours.
You should be able to use this with a micro-USB charger attached (flat mode), but we caution that it may impact on power bank life as micro-USB does not have smart charging like USB-C USB-PD.
Why so long?
The test 44mm Apple Watch 4 had a mesh band. Our tester placed it on the BOOST↑CHARGE vertically in bedside mode (not flat on a table as you would expect). We guess using it vertically means a less accurate charge plate placement and therefore some additional loss of efficiency.
For the fourth test he placed it horizontally (flat) and it came down to just over three hours.
Recharges in the tank
Assuming your Apple Watch lasts approximately 18 hours (depends on the version, size and use) the BOOST↑CHARGE Power Bank 2K was exhausted after the third charge, so it has about 54 hours juice in it. Belkin claims 60 hours so, pass.
MFi Certification means that the BOOST↑CHARGE Power Bank 2K for Apple Watch has is specifically for the Apple Watch and meets Apple performance standards.