Powerbanks running from solar

So i have a 21w anker panel, currenlt charging a nitecore f1 18650 charger/ powerbank. With a xtar mc1 on the way , the xtar has great solar reviews. What i need now is a 10amp powerbank with a low input threshold for charging from solar in most conditions , how do the anker power banks stack up ? Can anyone recommend a powerbank that can handle low amp solar charging ? Thanks Ant.