After my brief experiment with a lower-spec’ed solar power bank, I decided to buy this ToughTested Solar ROC16 16,000 mAh with PD Power Delivery model and test it over several days.
Results follow.
Day 1
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I connected the newly purchased power bank to an electric outlet and charged to full, in accordance with the instructions. Then I disconnected it from the outlet and left it exposed to fairly direct sunlight at a window.
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(1st Charge) I connected the powered-on Librem 5 to the power bank using the L5’s cable (USB-C to USB-C). The L5’s charging light illuminated, and the phone started charging.
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I left the L5 powered on and connected to wifi only, with no other applications running.
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From a starting charge level of 41%, the L5 reached 99% in 3 hours, at which point I disconnected it and allowed it to drain over several hours to 41% again.
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(2nd Charge) I connected the powered-on L5 to the power bank again (still next to the sunny window, no electrical connection), this time with only the mobile network connection running, and it again charged to 99% in 3 hours.
Day 2
- (3rd Charge) Connected L5, mobile network enabled, wifi disabled.
purism@pureos:~$ cat /sys/class/power_supply/tps6598x-source-psy-0-003f/uevent
POWER_SUPPLY_NAME=tps6598x-source-psy-0-003f
POWER_SUPPLY_TYPE=USB
POWER_SUPPLY_USB_TYPE=SDP DCP CDP C [PD]
POWER_SUPPLY_ONLINE=1
POWER_SUPPLY_PRESENT=1
POWER_SUPPLY_CURRENT_MAX=1670000
POWER_SUPPLY_VOLTAGE_MAX=12000000
Start level: 41%
After 1 hour: 73%
After 1 hour, 16 minutes: 80%
After 1 hour, ~52 minutes: charging stopped (apparently no juice left), ~86%
purism@pureos:~$ cat /sys/class/power_supply/tps6598x-source-psy-0-003f/uevent
POWER_SUPPLY_NAME=tps6598x-source-psy-0-003f
POWER_SUPPLY_TYPE=USB
POWER_SUPPLY_USB_TYPE=SDP [DCP] CDP C PD
POWER_SUPPLY_ONLINE=0
POWER_SUPPLY_PRESENT=1
POWER_SUPPLY_CURRENT_MAX=1500000
POWER_SUPPLY_VOLTAGE_MAX=5000000
So that was 3 acceptable, adequate charges from the unplugged power bank, presumably from just the stored energy added during the original electrical outlet charging. The power bank had about 6 hours of constant, bright sun exposure on Day 1, but conditions over these first 4 hours on Day 2 were gray and overcast.
Day 3
- I charged the power bank overnight to full (via electrical outlet)
- drained the Librem 5 during the morning
- then connected the L5, powered off, and started charging until the LED was extinguished
- disconnected and powered on
(1st charge:)
Starting charge level: 25%
Ending charge level: 99%
Time elapsed: 3 hours, 40 minutes
After charging, the power bank’s remaining charge was at 3 out of 4 LEDs.
(Are those graphs helpful? I don’t know.)
Day 4
(1st charge:)
Libem 5 powered on, mobile network and bluetooth active. (Bluetooth not linked with any other devices.) Wifi off.
Librem 5:
Starting charge level: 40%
Ending charge level: 99%
Time elapsed: 3 hours, 5 minutes (charging stopped by me)
Power Bank:
Charge level start: 3 blue LEDs out of 4 (left over from Day 3)
Charge level end: 1 blue LED out of 4
Temperature readings at 99% charge:
(2nd charge:)
As the power bank’s LEDs were down to just one illuminated, I took the opportunity to let it accumulate some solar energy, although it probably still has residual power from the last plug-in charge.
Power bank
Solar charge time: 6 hours, indoors (3 in bright sunlight, 3 in ambient sunlight, positioned in or near a window
Librem 5
Charge level start: 35%
purism@pureos:~$ cat /sys/class/power_supply/tps6598x-source-psy-0-003f/uevent
POWER_SUPPLY_NAME=tps6598x-source-psy-0-003f
POWER_SUPPLY_TYPE=USB
POWER_SUPPLY_USB_TYPE=SDP DCP CDP C [PD]
POWER_SUPPLY_ONLINE=1
POWER_SUPPLY_PRESENT=1
POWER_SUPPLY_CURRENT_MAX=1670000
POWER_SUPPLY_VOLTAGE_MAX=12000000
Then I powered down the phone and continued charging.
The phone’s charging LED extinguished after 1 hour.
Charge level end: 70%
So, less effective charging than on Day 1.
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(…to be continued…)