My astronomy project:
Setup astroserver with Raspberry Pi4

Content:

1. Introduction
2. The passive cooler
3. Formatting the microSD card and transfer of the mirror file
4. Setup KStars and Ekos
5. Setup INDI Control Panel 'Telescope simulator'
6. Setup INDI Control Panel 'Canon DSLR'
7. Battery test
8. Indoor test of focus control
9. First Light
10. Setup drivers peripheral

Related projects:

• HEQ5 as portable mount
• Pentax 645 300 mm ED IF f/4 lens
• KStars / Setup GPS Raspberry Pi4
• KStars / Setup WIFI Hotspot Raspberry Pi4
• KStars / Linux commands and udev rules

Note:
I take no responsibility or liability for what are written here, you use the information on your own risk!

7, Battery test:

Before proceeding I'm very curious about the power consumption. Can I power it by a small USB backup battery ?

First I had it running in idle mode, it took four hours until the LED indicator drop one step.

I let it continue with battery power another four hours when I doing the setup. Now total eight hours in operation and still 75 % of the battery power left. After nine hours it dropped down to 50%. Looks very promising. The battery has a capacity of 10 Amph. This battery also power the heating band.

When I discussed this with a friend he said: "Maybe the heat from the cooler can be used as a dewheater", not a bad idea when you use it as a portable equipment and want the batteries to last for a long time. The dewheater takes a lot of power and if I can replace that heat with something that's already there it will be great. I think it will work if I just have the cooler close enough to the lens, 5 mm. A more advanced solution will be to wrap around the lens with a Copper band and connect it to the cooler.