Power for the mount and for all the devices

[orfest]

Hi,

I've been trying out astrophotography from home, where 220V socket is available with unlimited power.

I want to be taking my setup to the field next year, but I'm wondering how to power all the devices.

Current setup:

• The mount (10micron GM1000) needs 24V@3A (peak 4A). To get 24V@3A I need 12V@6A
• DSLR that can run from batteries, and I have lots of spare batteries on standby
• Raspberry Pi to control the devices, 5V@3A, equivalent to 12V@1.25A
• Dew Heater that I've just got, but never used, needs 12V@1A

I'm considering some upgrades in the near future:

• An autofocuser, 12V. Power requirements should be minimal.
• Replace DSLR with a cooled camera, 12V. I don't know what I'll get, but top models need 3A. Don't know how much of it is used by cooling, and how much is used by the sensor.

Questions:

1. Is it safe to power the mount from a DC hub? My mount's manual says "Please don’t use unregulated power supplies because the output voltage of these units is not good enough to operate the mount.". I didn't find anything that says the warranty is void if not using the pre-approved power supplies.
2. If I don't want to power the mount from the DC hub, how can I power the mount and the DC hub from the same battery? I saw these funny devices on Aliexpress but don't know if they are any good: https://www.aliexpress.com/item/32911966417.html
3. What kind of batteries do you use to provide multiple Amperes to all the equipment all night long? Mount needs 6A (at 12V), cooled CMOS camera needs 3A, dew heater needs 1A, Pi needs 1.25A. That's 11.25A at 12V, which is 135W of power. The battery must be huge.

I saw discussions of various DC hubs here:

 

[chanrobi]

You'll need one of these https://www.jackery.com/pages/portable-power-stations

For DSLR, you can use multiple batteries, but you an also get a dummy battery with a usb plug. My current setup does not have as much power needs as yours, so I just run everything off a 30k mah, usb battery bank with the appropriate outputs.

A battery like the linked should have a dedicated port for each thing you're running. Don't think splitting them is a good idea

Edited November 30, 2020 by chanrobi

[orfest]

30 minutes ago, chanrobi said:

You'll need one of these https://www.jackery.com/pages/portable-power-stations

Thanks for the link, haven't seen it before.

The largest model has only one DC output though. I'd like at least 2 DC outputs. Converting DC->AC->DC is wasting power.

32 minutes ago, chanrobi said:

get a dummy battery with a usb plug.

I have a dummy battery with an AC plug. Good idea to get the one with the USB plug too. Thanks!

[StevieDvd]

There are many portable battery supplies that can be used that supply a steady regulated voltage designed for such a use - see https://www.firstlightoptics.com/batteries-powerpacks.html for some examples and price ranges. Others use leisure batteries and their own connections boxes.

Before you decide it may be worth noting that one of the issues many try to resolve is a tidy cable setup on the mount (whether fixed base or portable). So have a look at Pegasus Power Boxes, some of these have an option for powering dummy DSLR batteries. There are other makes and typically you use one connection from your portable source.

 

[chanrobi]

3 hours ago, orfest said:

Thanks for the link, haven't seen it before.

The largest model has only one DC output though. I'd like at least 2 DC outputs. Converting DC->AC->DC is wasting power.

I have a dummy battery with an AC plug. Good idea to get the one with the USB plug too. Thanks!

There are many options for battery packs like that, that was just one example of a company providing it.

If you look at the form factor, they are essentially a car battery with a engineered for you interface to plug in various things, it's up to you to find the battery within the budget and the # of ports and power you need