2

Whilst I am OK with software, hardware especially electronics is not my field.

I have a Raspberry Pi. It is enclosed in a water-proof case apart from an aperture that lets out a USB-C cable. Inside this case are my RPi and a USB power pack powering this RPi. When the RPi runs the camera captures motion for as long as there is power in the USB bank. When run down I attach the USB-C cable to a wall charger and the USB power bank is recharged.

  1. At any point do I need a UPS system?

    It will vary when the power bank runs out (depending on work by the RPi) so as I understand it the UPS battery could also run out as well with no chance to recharge the USB charger in time.

  2. Is my understanding correct or do I need to do more research?

4
  • 2
    The main advantage, if you mean a UPS HAT not a normal separate large box UPS, would be protection against sdcard corruption (ie power cuts out in the middle of a disk operation). How important that is depends on whether or not you care about the data. The worst that can happen, I believe, is that you need to reinstall the system.
    – Tomas By
    Jul 10, 2020 at 18:14
  • @TomasBy Hi. Thanks for taking time to reply. Ok, so it acts as a 'barrier' when the usb power runs down and the ups shutsdown the pi? is that correct?
    – user11286
    Jul 10, 2020 at 18:16
  • Yes, I suppose you could say that.
    – Tomas By
    Jul 10, 2020 at 18:17
  • You need to rethink how you operate your system. To run the USB powerbank empty and just let the Raspberry Pi DIE is a BAD practice. To introduce a USP that can signal the Raspberry Pi in advance of power cutoff is a better practice. Dedicated Raspberry Pi UPS hats does this via a GPIO pin and professional UPS does it over a serial interface (DB connector or USB) with the NUTS protocol.
    – MatsK
    Feb 9, 2023 at 11:12

3 Answers 3

1

The main advantage, if you mean a UPS HAT not a normal separate large box UPS, would be protection against sdcard corruption (ie power cuts out in the middle of a disk operation). How important that is depends on whether or not you care about the data. The worst that can happen, I believe, is that you need to reinstall the system.

1
  • Thanks. Just the clarity i needed!
    – user11286
    Jul 10, 2020 at 18:19
1

When a software upgrade is going on , a sudden shutdown can hamper that update along with sdcard. I have faced many problems like this and always wanted to use an UPS. If you think you are going to do frequent software updates then you can use a n UPS. It is also good for saving documents while working.

1
  • Hi been doing a lot more research in this. My Daemon saves images form the pi camera every second. if the only risk is a unsaved image then i am fine with that. The Ups seems very expensive (for me anyway). I just do not want my SD card frazzled. Is the only main risk data failure do you know?
    – user11286
    Jul 12, 2020 at 15:43
0

My experience with shutting down the Pi 4 incorrectly (removing power from wall or UPS) is that it will corrupt the SD card image, sooner or later (even putting the SD card to read-only doesn't help me).

An UPS is highly recommended in such case, but you would also have to (ideally) implement a system that shuts down your Pi on low battery - which involves reading the battery voltage and a script to shut down based on given readings. This has been done (Preventing SD card corruption in the event of power failure - amongst other sources).

Of course a poweroff button is an analog/mechanical option to use (Shutdown/reboot Raspberry using a pin other than pin 5)

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.