Jump to content

Sketches

Powering all the gear, but no idea


Recommended Posts

Hi all,

Over the past month or so I've been gathering gear to go with my Sony a7iv to step into the world of astrophotography, after having a few mixed results with trying my hand at shooting the milky way.

First was the mount, Sky-Watcher Star Adventurer GTi which I've used for a couple of imaging sessions with my Sony 200-600mm. I picked this mount to keep my setup reasonably light so I'd get out to sites, and also figured having GOTO would be better than not. Since my last session a few weeks ago I've picked up a Williams Optics Z61 scope and an original ASIair and ASI120mm mini for guiding; now I need a solution to power this along with a dew heater or 2 (does a guide scope need one?). 

What would be the best way to power all this, while keeping it reasonably light weight? I've looked on Amazon and the array of portable power stations is mind boggling and are any of them suitable? Would going for something like a Celestron PowerTank Lithium Pro be my best option and would it provide enough power for around 4 hours a session? If I stick with AA batteries in the SWSA GTi, what other options are there for powering the ASIair, guide camera and dew heater(s)?

Thanks

 

 

 

Link to comment
Share on other sites

For a 4 hour session you can probably get away with dew shields rather than dew heaters.  That's how long I image for usually and with shields I've not had any issues even with fairly high humidity.  Go DIY with some craft foam.  You absolutely will need a few shield/heater for the guide scope.  Remember you can make the shield surprisingly long on the scopes.

Link to comment
Share on other sites

A lot of these LiPo batteries are listed in milliamps, 1000 mA = 1 Amp, so if it is a 20.000 mA battery it will power something of 1 Amp power usage for 20 hours.

To size a battery for your setup you need to add up all of the amps required. That is what you need for 1 hour.

If you plan a 4 hour session you need to multiply by 4. 

That is the minimum amount you need so if you want a safety factor from cold weather (lipo do not like being cold) or age, take your required amount, multiply by length of average session then times that again by 2. That final number is the size of battery you need.

 

The Celestron pack is alright but overpriced, I would also suggest you run a separate pack for your heaters so you are not using power for your optics/ mount. 

Edited by Gabby76
Link to comment
Share on other sites

An asiair gen2 or 3 will have provided more flexibility as it has 12v out ports which you could have used to power the mount, and prior powering the asiair with the battery pack.

No big issue as having a gen1 also provides alternative flexibility in that you can power it with a usb power bank for which you have a multitude of capacities to choose from and likely you may already own one.

I typically use a 20000mAh usb power bank for the gen1, the camera gets it power via its asiair usb connection. The spare usb slot in my power bank I sometimes use to power one dew heater. As per the suggestion above though it is better to power the dew bands separately with their own power source to not affect the supply to your "vital" kit, they also draw a lot of power so will deplete their source over a session quite quickly, its better to have separate sources due to this effect alone.

For my gen2 asiair the Celestron Lithium LT works great for 3-4 cold hours powering everything other than the dew bands but won't work with your configuration as a single source, unless you use it to power the SAGTI only (the usb connection output of the LT doesn't work at the same time as the 12v out, it's one or the other).

Also I think you'll enjoy the z61, it's an excellent scope.

Edited by Elp
Link to comment
Share on other sites

Thanks for the replies and suggestions.

The SAGTi is probably fine on rechargeable AA's for the time being. Spitting the dew heater power from the mount/guiding makes sense.

Just need to get a powerbank for the ASIair, much easier than expected

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.