Q: Can this power bank be charged by a solar panel?

Yes, I charge it with the SUNKINGDOM 40W 18V Foldable Solar Panel Battery Charger with Dual-port (18V DC&5V USB) Output for Travel,Hiking,Camping Compatible with Laptop,Tablet,Computer,Storage Battery,iPhone,iPad,Android Smart Phone and Any Other Electronic Device(Camouflage), which includes the necessary attachment, too

Question 1

Does this support pass-through charging (charge the external battery while in use)?

Accepted Answer

yes! Can support charge and discharge at the same time. That is charge the external battery while in use

Question 2

Will this work with the asus gl552vw laptop?  it's a 19v 6.32a 120w  3/2 pin compact power

Accepted Answer

It will probably charge it, but your laptop might use power a bit faster then your batter can provide it. That laptop looks similar to my Lenovo y50 spec wise, which also has a 120 watt charger. The battery works for me just fine, and charges faster then my laptop discharges.

Question 3

Can this power bank be charged by a solar panel?

Accepted Answer

Yes, I charge it with the SUNKINGDOM 40W 18V Foldable Solar Panel Battery Charger with Dual-port (18V DC&5V USB) Output for Travel,Hiking,Camping Compatible with Laptop,Tablet,Computer,Storage Battery,iPhone,iPad,Android Smart Phone and Any Other Electronic Device(Camouflage), which includes the necessary attachment, too

Question 4

So 50000mAh means it has that much space of the thing to be fully charged and the 185Wh is what it can handle at pek power?

Accepted Answer

50,000 mAh is a measure of capacity that's relative to the average voltage of individual cells during discharge, which is 3.7V, for LiPo chemistry.

Thus, if you could actually connect a 3.7V device, which you cannot, and that device pulled 1Amp of current (1000mA) continuously, you could theoretically operate the 3.7V 1A device for (50000 mAh / 1000 mA) = 50 hours, but the BMS (battery management system) will typically protect the LiPo cells from being discharged any deeper than about 90% of theoretical capacity, so... (0.9 * 50000 mAh / 1000 mA) would yield 45 hours of operation on one charge cycle (for a 3.7V device pulling 1A if current).

So now, if a little bit of four-function arithmetic hasn't already sent you screaming into the night, you might be wondering how to calulate hours of operation for a 5V, a 12V or a 20V device (at a given current demand), as the Maxoak K2 actually has output jacks for these voltages, though not for 3.7V.

Here's an equation that should get you in the ballpark for all 5V, 12V or 20V devices:

Hours of operation = (3.7V / Voltage of jack in use) * (0.9 * 50000 mAh) / (mA current consumed the by device)

Of course, the device you connect to an output jack must match the Voltage supplied by that jack AND the device must not pull more Amps of current than the maximimum Amp rating specified for each output jack. (See the item description.

185Wh is just another measure of capacity, but it's not tied to the 3.7V average of individual LiPo cells, nor even to a specific current demand.

Note, just for fun, that 185Wh / 3.7V = 50A ( or 50,000 mA).  In other words, the 185Wh capacity rating (at any voltage) does not conflict with the 50,000 mAh capacity rating (that's tied to 3.7V).  😁  My hat's off to the folks at Maxoak, for getting this right, because many battery bank manufactures not only greatly exaggerate the mAh capacity rating, but rarely include the corresponding Wh rating and, even if they do, the math proves that one or both capacity ratings are inaccurate, even before testing the capacity of the product!  I have thoroughly tested this K2 battery and their Bluetti EB240 and found the Maxoak specs to be honest! No monkey-business!

Ok, where was I?  Oh yeah...

If you have a DC device with specs stating its Voltage requirement, but power consumption is stated in Watts or milliWatts (instead of Amps or milliAmps), you can calculate the hours of operation as follows:

Hours of operation = (0.9 * 185Wh) / Watts of power consumed by the device)

Class dismissed!

Brand	MAXOAK
Item model number	K2-50000mAh
Item Weight	2.77 pounds
Product Dimensions	8.1 x 1.1 x 3.1 inches
Item Dimensions LxWxH	8.1 x 1.1 x 3.1 inches
Color	(19.10)/Gm.3650
Voltage	3.7 Volts
Batteries	1 Lithium Ion batteries required.
Manufacturer	maxoak
ASIN	B00YP823NA
Is Discontinued By Manufacturer	No
Date First Available	June 2, 2015

MAXOAK Laptop Power Bank 185Wh/50000mAh(Max.130W) Portable Laptop Charger External Battery Pack for Laptop iPad Phone Notebook

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