What qualities does the power bank need in order to be a good candidate for powering a Pi and DAC HAT?
mA/hr :
I see that there are power banks ranging from 10,000mA/hr to over 20,000mA/hr with two USB-A outputs, one rated at 1A, the other rated at 2.4A. Since the power bank will be used with the power bank's input always connected to a 5V SMPS, does the mA/hr rating of the battery matter while powering a Pi?
Quick-Charge ports:
All the current Anker 20,000mA/hr power banks have a Quick-Charge port (QC). I assume these have programming to supply a good burst of current to get the smartphone battery to charge as quickly as possible. Would this pose a danger to the Pi or Pi+DAC? There's Quick Charge 2.0, Quick Charge 3.0, Apple 2.4A quick charging... This stuff is confusing.
https://www.powerbankguide.com/anker-pow...s-to-know/
Auto shutoff programming:
I was worried that latest-design power banks would detect that they were fully charged and shut themselves off/power back on depending on current draw, even with the battery input connected to a 5V SMPS. I didn't want the Pi to be shut off prematurely. The current Anker power banks all have verbiage on their packaging touting all sorts of automatic sensing wizardry. Cause for concern?
I decided to test the waters by purchasing a generic 10,400mA/hr power bank with a 1A port and a 2.4A port.
http://www.microcenter.com/product/48535...k---silver
At this point I'm powering my RPi3 with Allo Boss (older version) together from the one 2.4A port. It seems to be working fine. I used my RPi SMPS to charge the power bank up to full, which took all night.
The power bank has a switch on its side, not explained anywhere on the packaging. Seems to be an on/off switch. It doesn't seem to do anything while the power bank input is connected to the SMPS.
A review for this particular power bank mentions that it does not work as a cheap UPS for a RPi3.
"I was looking for a battery usb bank that I could use to power a raspberry pi 3 like an ups. This battery bank fails to perform that task. The battery life is as advertised and it does put out 2.4 and 1 amp on each of its outputs. The problem comes when you plug in the power cord to charge while it is also powering your device. The input charge is only 1 amp or maybe a bit higher but not the 3.4+ amps needed to supply the ports and also charge at same time. So when you plug in a power source even one that is 5+ amps it will still only deliver 1 to 2 amps max regardless of what the battery charge is at and when you remove the power cord it will cycle power on the ports before it starts to deliver its power from the batteries. As a battery bank for out and about to recharge your phones and such it works great but as a back up to power for a usb device that needs full time power it fails."
I wonder if this means one needs to choose a power bank that is capable of delivering 3.5A or more current to loads on both output ports? Does this mean I'm basically powering my Pi from the SMPS anyway, and merely topping off the charge to the power bank/battery at the same time? That would mean the power bank is doing nothing for the Pi+DAC, and any improvement I think I hear is due purely to placebo effect.
However, the statement, "...when you plug in a power source even one that is 5+ amps it will still only deliver 1 to 2 amps max regardless of what the battery charge is at..." suggests that the battery is actually supplying the power even when the power bank's input is connected to a 5V SMPS. In that case the power bank would be providing DC output from its battery, even if the power bank's stated capacity is only 10,400mA/hr. And, if DC supplied from the battery is cleaner than the DC coming straight from the SMPS, then this would be an improvement for the power to the Pi+DAC, even if the battery pack used is rated at only 10,400mA/hr.
I may end up with this:
Thoughts, anyone?
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mA/hr :
I see that there are power banks ranging from 10,000mA/hr to over 20,000mA/hr with two USB-A outputs, one rated at 1A, the other rated at 2.4A. Since the power bank will be used with the power bank's input always connected to a 5V SMPS, does the mA/hr rating of the battery matter while powering a Pi?
Quick-Charge ports:
All the current Anker 20,000mA/hr power banks have a Quick-Charge port (QC). I assume these have programming to supply a good burst of current to get the smartphone battery to charge as quickly as possible. Would this pose a danger to the Pi or Pi+DAC? There's Quick Charge 2.0, Quick Charge 3.0, Apple 2.4A quick charging... This stuff is confusing.
https://www.powerbankguide.com/anker-pow...s-to-know/
Auto shutoff programming:
I was worried that latest-design power banks would detect that they were fully charged and shut themselves off/power back on depending on current draw, even with the battery input connected to a 5V SMPS. I didn't want the Pi to be shut off prematurely. The current Anker power banks all have verbiage on their packaging touting all sorts of automatic sensing wizardry. Cause for concern?
I decided to test the waters by purchasing a generic 10,400mA/hr power bank with a 1A port and a 2.4A port.
http://www.microcenter.com/product/48535...k---silver
At this point I'm powering my RPi3 with Allo Boss (older version) together from the one 2.4A port. It seems to be working fine. I used my RPi SMPS to charge the power bank up to full, which took all night.
The power bank has a switch on its side, not explained anywhere on the packaging. Seems to be an on/off switch. It doesn't seem to do anything while the power bank input is connected to the SMPS.
A review for this particular power bank mentions that it does not work as a cheap UPS for a RPi3.
"I was looking for a battery usb bank that I could use to power a raspberry pi 3 like an ups. This battery bank fails to perform that task. The battery life is as advertised and it does put out 2.4 and 1 amp on each of its outputs. The problem comes when you plug in the power cord to charge while it is also powering your device. The input charge is only 1 amp or maybe a bit higher but not the 3.4+ amps needed to supply the ports and also charge at same time. So when you plug in a power source even one that is 5+ amps it will still only deliver 1 to 2 amps max regardless of what the battery charge is at and when you remove the power cord it will cycle power on the ports before it starts to deliver its power from the batteries. As a battery bank for out and about to recharge your phones and such it works great but as a back up to power for a usb device that needs full time power it fails."
I wonder if this means one needs to choose a power bank that is capable of delivering 3.5A or more current to loads on both output ports? Does this mean I'm basically powering my Pi from the SMPS anyway, and merely topping off the charge to the power bank/battery at the same time? That would mean the power bank is doing nothing for the Pi+DAC, and any improvement I think I hear is due purely to placebo effect.
However, the statement, "...when you plug in a power source even one that is 5+ amps it will still only deliver 1 to 2 amps max regardless of what the battery charge is at..." suggests that the battery is actually supplying the power even when the power bank's input is connected to a 5V SMPS. In that case the power bank would be providing DC output from its battery, even if the power bank's stated capacity is only 10,400mA/hr. And, if DC supplied from the battery is cleaner than the DC coming straight from the SMPS, then this would be an improvement for the power to the Pi+DAC, even if the battery pack used is rated at only 10,400mA/hr.
I may end up with this:
Quote:5) Power the two separately (with the appropriate jumper removed from the DAC): the RPi via the wall-wart, the DAC via the Anker.
Thoughts, anyone?
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