Hint: Its all about the cables!
The HP Chromebook 11 broke new ground by using a fast 3 Amp Micro-USB charger. It also generated a lot of bad publicity early on when the US chargers had to be recalled due to overheating. The USB charging is effective because the computer has a relatively small battery, and thus achieves a fairly rapid charge. To get reasonable battery life despite a very bright 300 nit screen, it uses a relatively low powered processor, limiting it’s performance. At a weight less than a Mac Book Air, it is a joy to carry, and on short business trips, the ability for the single, light charger to charge every device I carry is seductive.
But there are reports that the chargers are difficult to replace if they fail. Any Micro USB charger can charge the Chromebook overnight, but they lack the power to charge the machine while it is running. A 1 Amp phone charger will raise an alert that it is a low powered charger, and the running device will still bleed down slowly.
My experience with a variety of chargers and cables shows that while many chargers will deliver the required 3 Amps, the Cable used is the big leveler. The original HP charger is rated at 3 amps and works fast. I have not dismantled it, but I am sure it uses heavy gauge wire.
Most USB cables use thin #28 or #24 AWG wire. Non-intuitively, lower numbers are thicker and therefore better conductors of current. The USB charger supplies 5 V (volts) and the thicker the wires the better. Thin wires provide resistance, and power coming from the charger is lost as heat in the cable. So as a rule of thumb, shorter is better, and thicker is better. Over the last 12 months I have tested about 30 different cables. Some were quite expensive, many were not. The shortest ones worked best, but at 200 mm (8 inch) cable is not very convenient.
The single best charging cable I have found comes from PortaPow in England. It is the PortaPow Fast Charge Micro USB Cable (Length: 100cm (3.3ft)) Most cables of this length would only deliver 0.6 – 0.7 A. That translates to about 3.5 W, not enough to charge and run a Chromebook. The PortaPow cable delivers 1.75 A or about 8.75 W. from the same power supply. I believe my cable is #22 AWG, but they have since increased the size of the conductors to #20 AWG and I have two more on order.
Lets look at three chargers that work well with this cable. In each case the Chromebook is running with multiple tabs open, multiple docs, Gmail, Drive and some web pages. WiFi is on, and I am using a Bluetooth mouse. Brightness is at about 80%. In all cases they are reported as low power chargers.
My favourite charger is the Anker 40 watt, 5 port IQ+ charger. It has been superseded by a 60 watt version, but mine is working fine and does not need an upgrade. With the PortaPow cable, it delivers 1.75 A and the Chromebook is working and charging steadily. If I close the lid and hibernate for 30 minutes, it will charge up by 12%. Basic arithmetic suggests about 4 hours to go from 20% to 100%. With the computer working, of course, it will be MUCH longer, but will get there.
I also have a Kensington 2 amp, 4 port charger that can be plugged into the power socket or be used with a figure 8 cable instead of the adapter. It charges the Chromebook at 1.45 A and has enough power in reserve to also charge my smartphone without reducing power to the Chromebook.
Finally, the ASUS 2 A wall-mount charger that came with my Nexus 7. This small charger is rated at 2 A and pushed about 1.35 A through the PortaPow cable. This is enough to run the Chromebook with a little left in reserve for charging. With my current settings it is charging at about 3% per hour. I would suggest playing video at full brightness will cause the battery to drop.
There is an endless parade of USB Chargers, and the cheaper ones are not worth the time. Ask yourself if you really want a $5 charger between mains voltage and your expensive device, and then move on to a name brand charger.
My summary of the best options:
If you already have a 2 amp charger lying around ( I am sure you do) simply buy the PortaPow fast charging cable, and you are in business. The Nexus 7 charger weighs 62 grams (2.2 oz) with an Australian plug.
If you want flexibility and low weight, the Kensington 2 amp charger (112 grams ( 4 oz)) comes with a range of international plugs, and can be used with a figure 8 cable if the power outlet is inaccessible and can charge four devices (up to 2 amps) simultaneously.
For speed and power, there is no substitute for the Anker 5 port IQ+ charger. It weighs in at a hefty 250 grams (8.8 oz) with a cable but I have been on vacation with four people, a chromebook, three tablets, four smartphones, a USB powered WiFi hotspot and assorted keyboards mice and Bluetooth headsets and the Anker handled the lot perfectly.
My Review of the Anker Charger is here, you might enjoy it.
I also reviewed the HP Chromebook 11, and decided It is my favorite Chromebook despite it’s limitations!