Anker 737 Power Bank, 24,000mAh 3-Port

The good: does what the description says when not in passthrough. The bad: passthrough is more limited than I hoped. I'll detail out every combination of inputs and outputs so you can see if it works for your use case. My primary use case is charging my Dell laptop which requires 20V 5A (100W) and refuses to charge at all (even slowly) with anything less than 5A. First, it will passthrough if your source (i.e. wall charger) and drain (i.e. laptop) provide/request the same voltage and maxium current. For example a 20V 5A source and 20V 5A drain will work, although the internal battery will not charge at all even when the drain is full and not actually pulling any current. There's no point in passthrough in this case since the internal battery never charges. Next, the maximum current available from the source must be greater than or equal to the maximum current requested by the drain. For example, if the power source is 20V 1.5A and drain requests 20V 5A then the battery will not make 5A available to the drain. It will charge its internal battery at 20V 0.6A (12W), even if the source can supply 1.5A. In this case, my Dell laptop doesn't charge at all. You can't use this device to "upgrade" chargers to higher currents by using the internal battery. Next, if the source is 20V 5A and the drain requests 20V 3.25A (65W, such as most laptops) then the battery will passthrough up to 65W, but the internal battery still will not charge even though there's at least 35W available to use for charging, and the internal battery will not charge even when the drain is full. Once again, passthrough is useless for charging >= 65W devices like laptops. Next, if the the source is 20V 5A and the drain requests < 65W (such as most phones) then for the first 45 seconds it'll just passthrough the drain current, but then after 45 seconds it will start charging the internal battery. You may see conflicting info in other reviews, I believe this is because they didn't wait the 45 seconds. Therefore if you're using this to charge small devices like a phone then this is a good use case for passthrough since both the phone and internal battery charge at the same time. Next, if the source device is not a USB PD device and the drain is a mandatory USB PD devices (such as a laptop) then the output is disabled and internal battery does not charge. Once again, you can't use this battery to "upgrade" inputs to higher demand drains. Next, if the source is not a USB PD device and the drain is an optional or non-PD device, such as a phone, then it'll passthrough the drain current at 5V but not charge the internal battery, even if there is capacity available to charge the internal battery. Interestingly, the input and output voltages differ: in my test the non-PD source did support Qualcomm Quickcharge so it provided 12V, but the battery only provided 5V output to the drain (a phone). P.S. I focus on the USB C ports above, but it appears in all passthrough cases the battery will supply at least 5V 0.8A to the USB A port, and it'll pull that from the source not the internal battery. When the source maximum current is greater drain maximum current, or with everything else unplugged, it'll provide 5V 1.2A to the USB A drain. I haven't been able to get it to output the advertised 9V or 12V modes on the USB A port.