Does anyone know of a usb power bank (i.e. a device that can provide backup power to the tempest hub as opposed to the tempest station in the event of a power failure) that provides pass-thru charging and does not cycle its output when power is removed or applied?
If you were not aware, Tempest’s Hub Power Bank does provide pass-thru charging, but does cycle its output when power is removed. As a result, this behavior can result in a data loss in the following scenario:
Power is removed from the hub for some amount of time (for example, a day).
Power is applied to the hub for a small amount of time (for example, a few seconds).
Power is removed from the hub for some amount of time (for example, a few seconds).
Power is applied to the hub.
In the above scenario, I believe all of the data that is cached in the hub during the day that power was initially removed will get lost (i.e. disappear) when power is removed for the second time at Step 3. If the hub has not completely uploaded its backfill data to the tempest servers between Step 2 and Step 3, that data cannot be recovered and will be lost forever.
In my neighborhood, I often see the power go on and off several times before it stabilizes after a long power failure event. As a result, the hub is often unable to upload all of the data it collected during the power failure because it gets reset due to the power bank’s output cycling during this time.
Besides the Tempest Hub Power Bank, I have also tried using an Anker PowerCore Slim 10000 Model A1229 and an Iniu PowerPaw Slim 10000 Power Bank BI-B41.Unfortunately, these power banks also do not hold their output during all power remove/apply events.
The feature is called pass-through charging. Many do not do it, and some that have been reported by others to have the feature suddenly don’t have it any more in the same exact model shipped months later.
I’ve had this saved in my Amazon wishlist for a few years, but never ordered one to test it:
There was a thread ages ago that suggested that there was then something in the electronics of the Hub that made it not work too well with some UPS or UPS-like battery backup devices related to passthrough charging. Something in how little power the Hub sipped perhaps, but my memory is hazy. It was a long time ago…
Power banks designed for phone charging (most on the market) sometimes have a feature where they will shut off when they think that the attached phone is full. The Hub draws so little power that the power bank shuts off…
Unfortunately, I am beginning to question whether any usb power banks do not cycle the output power during power removal and/or during power re-application. Here are the results of my testing so far:
Tempest Hub Power Bank Model WF-TWSPBM6
Output Power does cycle when power is removed.
Output Power does not cycle when power is applied.
Anker PowerCore Slim 10000 Model A1229
Output Power is not provided when power is applied (i.e. no pass-thru charging).
Iniu PowerPaw Slim 10000 Power Bank BI-B41
Output Power does cycle when power is removed.
Output Power does not cycle when power is applied.
FYI: After performing a ton of internet searches, I finally found some messages indicating that output power is not cycled when power is removed or applied on power banks made by a company name Cuktech. As a result, I purchased some of these power banks and can indeed confirm this behavior with these power banks. Since I currently do not own an oscilloscope, I guess I really can only confirm these power banks do not cause the Tempest Hub to reset under these conditions.
Specifically, I tested 1) the CUKTECH 10 Power Bank 10000mAh 150W, 2) the CUKTECH 15 Power Bank 20000mAh 150W, and 3) the CUKTECH 20 Power Bank 25000mAh 210W. Unlike the CUKTECH 10 and the CUKTECH 20, the CUKTECH 15 will cause the temptest hub to reset upon pressing the button on the CUKTECH 15, which is used to turn on and off its display and change the charging mode.
Currently, I am planning to start using the CUKTECH 20 as the backup power supply for my Tempest Hub.