How to Properly Connect AC Power Bank to Solar Panel Using Charge Controller?

Hello all,
I recently bought an ac power bank however when tried to connect to the solar panel through a charge controller it did not charge. Unlike regular batteries the power bank has both input and output terminals. The solar controller need power which it cannot draw from the ac power bank input terminal. 
Could somebody advise what is the solution to this problem ? Do I need another smaller battery to power the charge controller ? Or should connect like : Solar Panel->Charge controller solar input terminal->Charge controller Battery output terminal->power bank output terminal->Charge controller Load terminal->power bank output terminal
Attached picture of the charge controller and the power bankSorry about the lack of knowledge but I only started this project recently.Appreciate all your help
Greg

Hi Greg,Happy to help, though where are the attachments?Regards

Hello Alan,
Thank you for your help 

Please see below 

Hi Greg,
Apologies, but I can't quite make out the part / model numbers on the units, do you have both  the charge controller and ac power bank details, so that I can have a look at the manuals?

Hello Alan,please see below stickers , hope it helps

What voltage does your solar charge controller put out? Your power bank may require a higher voltage than your charge controller puts out.Also, are you sure you need the solar charge controller? Your power bank may have it's own charge controller built in.

Hi Greg,I think Elizabeth is correct about the solar charger controllers output voltage versus the power banks input voltage. The charge controller is designed for a 12v battery system. The required power bank's input voltage is 15v.The charge controller has a float voltage setting of 13.7v to float charge 12v batteries, which it says is adjustable. It doesn't say how much it can be adjusted but if it could be adjusted up to 15v to suit your power bank input voltage, I would try this to see whether or not the power bank starts to charge.  This may not work either as the charge controller may need to "see" a voltage of approx 12v before it goes into float charge mode. I can't see any reference to the power bank having an inbuilt solar charge controller even though it suggests it can be charged via solar. It also suggests that it can be charged from your car, though i dont see how this would be possible since again it comes down to vehicle output voltage versus the required power bank input voltage. This power bank in my opinion is really only designed to be charged using the manufacturers supplied charging lead plugged into a normal outlet in your house prior to using it.Let us know how you go with it.
Alan

Hello Elizabeth & Alan,Please see below image. The power bank 15v input port does not give power to the solar controller only the output 12v port could but the power bank will not charge because there is nothing plugged into the input. For regular battery both input and output are the same ports.
Not sure if there is a built in controller , could not find any info on it.
Is it safe to charge the powerbank without the controller ? The voltage is fluctuating and also higher than 15v
Thank you

From what I remember, the "no-load" output of a "12V" solar panel is about 19V or so but if you connect it to a battery, the voltage drops.Alan mentioned something about the manufacturers supplied charging lead. I'd be interested to know what voltage you measure on that when it's not plugged into the power bank.

Your "Portable DC/AC Power Bank" label specifies "Input:DC 15V 2A" "Battery type:Li-ion" and warns "Do not charge except on the specified charging condition."Your power bank's input is labeled "15V INPUT SOLAR INPUT", so might be intended to be driven directly by a solar panel of the correct size. If the input is intended to be driven directly by a solar panel, the input may be intended to be driven only by a solar panel and too big a solar panel could damage the input. I hope Alan can find the manual.I suspect your solar charge controller is designed to charge a 12V or 24V lead-acid battery. The controller both charges the battery and slightly discharges the battery to monitor the battery's state-of-charge, so requires the controller output to be connected directly to a lead-acid battery. I think this charge controller is incompatible with your power bank, since the power bank uses a Li-ion battery.A 20-watt solar panel I have, is intended to charge 12V lead-acid batteries, and has eighteen silicon solar cells in series. This panel is rated 21.8V open-circuit, 1.25A short-circuit, and 17.6V 1.14A (to give 20W) at the maximum-power condition. I model this panel as a sunlight-derived 1.25A current source in parallel with (series string of eighteen forward-biassed silicon diodes). I sometimes use this panel through a charge controller to charge a 12V 7Ah (so 84 Wh) sealed lead-acid battery.Some of the charge controllers I have, short-circuit the solar panel when not charging the lead-acid battery. These controllers run their control circuitry from the battery, not from the panel.

Hello Elizabeth,
The adapter gives 15.1V power

Hello Peter,Thank you for the summary. 
Do you know of a charge controller which would be suitable ?
I am not sure if it meant to be direct input from the solar panel as the voltage fluctuates there and also most panels are 12v or 18v .

Just mount the charge controller on the panels and buy your own hinges and cables.

What about just direct connecting the panel
to the 15V input? I’d expect it to be quite tolerant so no need to be exactly
15V. It would need to be a big enough panel to provide up to 2A. If less the peak
input voltage might just sag to say 10V and fail to charge anything.  Safest bet would be to try a range of input voltages
from say 10 to 15V from a bench power supply whilst measuring current to
see how sensitive the unit is to voltage. If it’s a typical switched mode regulator
arrangement in the power bank current goes up as voltage reduces to maintain a fixed
wattage into the unit (assuming the battery is not already full). Then below a certain
voltage it reduces again until it reaches near zero when the switching stops. If
it’s a linear regulator current reduces as voltage reduces. But there is an intermediate
voltage state when conceivable it could get too hot. Worst still it might catch
fire (others more expert than me may have a view on this). So suggest trials be
done with the unit outside in case it catches fire.
 Also add a beefy 15V Zener diode(s) across the
input to ensure it never exceeds 15V. Needs to have enough wattage to absorb the
entire panel output.Alternative to the Zener may be to connect your
charge controller and a 12V lead acid battery (any old gash one will do) to the
panel too so they keep the panel voltage down. Load the battery up with a dummy
load to reduce the panel voltage. Not the most efficient solution though.

Those is interesting thoughts.