Skywatcher 7Ah Power Tank

Gr4h4m (Graham) · #1 07-05-2020, 04:21 PM

Well, the first item in my Astrophotography setup arrived yesterday.....the HEQ5PRO mount.

I'm just waiting on everything else at the moment but, in the meantime, it's got me thinking about how I'm going to power everything.

Here's a list of what I've ordered in terms of items which will require power:

HEQ5PRO Mount
ASI290MM Mini Guide Camera
ASI183MM Pro Camera
ASI Filter Wheel
2 X Dew Heaters
Pegasus Pocket Powerbox

Looking at the DC adaptor from Pegasus Astro it works out at about $240 with shipping which seems ridiculous.

I've been looking at the Skywatcher 7Ah Power Tank as an alternative with the other benefit being that it would give me the option of being mobile instead of having to rely on a 240v power supply.

My question is, does anyone with a similar setup use one of these Power Tanks?

I just want to make sure it's going to be sufficient to power everything on my setup.

As always, thank you in advance.

Merlin66 (Ken) · #2 07-05-2020, 04:28 PM

Graham,
I think you'll need a bit more than a 7Ah battery to give acceptable results.
Check the current required for the stuff you want to power and then double that number as a "Ah" target.
(This infers a 7Ah would power 3.5A for one hour before getting too low)
I use a couple of 20Ah gel cell golf buggy batteries - but don't use dew heaters....
Others have gone for large and heavy maritime boat/ caravan batteries - 120 Ah etc.

Gr4h4m (Graham) · #3 07-05-2020, 04:46 PM

Thanks for that.

I’ve just noticed they also do a 17Ah Power Tank which, if I can find one, might be the better option.

that_guy (Tony) · #4 07-05-2020, 10:20 PM

Don't get those powerpacks. They are over priced and under powered. A decent 38Ah deep cycle battery will run you $80 + a good multistage charger (is another $50). It's much more reliable and robust.

Outcast (Carlton) · #5 07-05-2020, 10:29 PM

I'm with Tony, go for a deep cycle battery, much better value for money.

Also, be aware that your guide camera & imaging camera will require power via their USB cables which I note, your Pegasus unit does not have...

If you are planning to use a laptop with it all then that's fine, they will draw power from your laptop... which means, you may need to think about how you plan to power your laptop... as the battery drain may mean it doesn't last particularly long on it's own battery...

My 1.41 cents worth...

RobF (Rob) · #6 07-05-2020, 10:45 PM

You could be getting distracted by remote power if you're new to the rig and astrophotography. You can get battery and charger to go to remote dark sites later, but you might be better off getting something like this initially.

https://www.jaycar.com.au/12vdc-7-5a...ocket/p/MP3575

After a few months of figuring out your rig in familiar surrounds at home, how to collect images, process etc may then be in a position to go offsite. When you're learning it can be a lot harder to be in a really dark remote site without internet etc.

While you're sorting out the "engineering" side of things, suburban light pollution (or even the moon) doesn't matter too much.

How do you plan to power the cameras and dew straps? the Pegasus Pocket Powerbox (or something like a "Rigrunner") could be invaluable to keep your wiring under control.

Gr4h4m (Graham) · #7 07-05-2020, 11:47 PM

Quote:

Originally Posted by Outcast

I'm with Tony, go for a deep cycle battery, much better value for money.

Also, be aware that your guide camera & imaging camera will require power via their USB cables which I note, your Pegasus unit does not have...

If you are planning to use a laptop with it all then that's fine, they will draw power from your laptop... which means, you may need to think about how you plan to power your laptop... as the battery drain may mean it doesn't last particularly long on it's own battery...

My 1.41 cents worth...

The ASI290MM Mini can be powered via the USB hub on the ASI183MM Pro which, in turn, is powered using a 12V 3A DC input which I can plug into the Pegasus Pocket Powerbox.

Maybe I’m best just sticking with 240V mains power to start with. Things have already escalated rather quickly. A couple of weeks ago I was considering picking up a ‘cheap’ telescope and now I’ve got all of this gear on the way.

Oh well, nothing like jumping in at the deep end, haha

RobF (Rob) · #8 07-05-2020, 11:53 PM

Yep, its a steep (but lots of fun!) learning curve. Will be lots of challenges, and best thing is figure the basic set up and connections, polor alignment, data connections - one step at a time, getting confident with the basic first.

If you've got some sort of pulse width modulator dew controller already, may not need the Pegasus initiallly either.

Have you got some sort of laptop sorted and suitable data/power connections (if that's the plan)?

Gr4h4m (Graham) · #9 08-05-2020, 12:09 AM

Quote:

Originally Posted by RobF

Yep, its a steep (but lots of fun!) learning curve. Will be lots of challenges, and best thing is figure the basic set up and connections, polor alignment, data connections - one step at a time, getting confident with the basic first.

If you've got some sort of pulse width modulator dew controller already, may not need the Pegasus initiallly either.

Have you got some sort of laptop sorted and suitable data/power connections (if that's the plan)?

I didn’t have anything in terms of dew control which is another reason why I went with the Pegasus Pocket Powerbox with it’s included environment sensor and ‘auto dew’ function.

I’ll be using the laptop I use for my sports photography so that’s one thing I don’t have to worry about thankfully. Got plenty of data and power connections.

Looking forward to everything arriving and getting it all out together. Like you say though, small steps. I’m certainly not going to be expecting much in the short term.

Outcast (Carlton) · #10 08-05-2020, 12:17 AM

Quote:

Originally Posted by Gr4h4m

The ASI290MM Mini can be powered via the USB hub on the ASI183MM Pro which, in turn, is powered using a 12V 3A DC input which I can plug into the Pegasus Pocket Powerbox.

Maybe I’m best just sticking with 240V mains power to start with. Things have already escalated rather quickly. A couple of weeks ago I was considering picking up a ‘cheap’ telescope and now I’ve got all of this gear on the way.

Oh well, nothing like jumping in at the deep end, haha

I can't comment on whether the 12V 3A then powers the two USB out ports on the 183mm Pro but, on the camera itself, I'm pretty sure it only powers the Tec Cooler. Your sensor/camera itself picks up power via the USB 3 connection...

240V is certainly an option... until you want to move out of your backyard to a nice dark site...

raymo · #11 08-05-2020, 01:27 AM

Well, I have always gone my own way, and with powering my gear it has
worked very well.
I bought my first scope nearly 69 yrs ago, but it was manually operated.
My first powered scope came along some 5yrs later, and I operated it with a motor cycle battery for several yrs. I then bought a more power hungry rig,
and bought a car battery to power it, which it did satisfactorily for, from memory, about 7 yrs. When my car battery became too weak to crank the car over on cold winter mornings, I relegated it to powering my rig, which it did for about 4 yrs before finally giving up the ghost. I have powered all my rigs
ever since with my retired car batteries, so have spent a grand total of the cost of one car battery over the last 54 yrs. One happy camper.
Pop down to your local auto leccy; they usually have a number of batteries
laying around that have been discarded when doing single to twin battery
conversions on 4WDs. These are usually around 80amp/hr, and will run your rig for years. The good news is that they often give them away, or maybe charge $20 or so, and will load test them first.
raymo

The_bluester (Paul) · #12 08-05-2020, 07:03 AM

Now that you mention that, I need to replace the battery in my wifes ute. I must give it an experimental crack on a cold night once I do and see how long it will run the rig. It is 88AH when new so even if it has lost half of that, and half again to the cold in winter it might perform pretty well.

On the other hand I have been thinking of building an enclosure for my imaging PC and some DIN rail power supplies, I have found supplies which are backed up by a 12V battery to keep things ticking over if there is a power interruption.

Gr4h4m (Graham) · #13 08-05-2020, 08:57 AM

Quote:

Originally Posted by Outcast

I can't comment on whether the 12V 3A then powers the two USB out ports on the 183mm Pro but, on the camera itself, I'm pretty sure it only powers the Tec Cooler. Your sensor/camera itself picks up power via the USB 3 connection...

240V is certainly an option... until you want to move out of your backyard to a nice dark site...

Yeah, I think I might just start with mains power. It’s all getting a bit complicated, haha

No doubt I’ll want to go mobile at some point though, like you say. I’m quite lucky to live in a Bortle 3 area but, knowing there’s Bortle 1 skies less than an hour away is pretty tempting.

NewBee101 (Robert) · #14 21-05-2020, 08:16 PM

Hi Graham, I would go along with what Merlin suggested, add up everything that consumes power, I mean everything, eg amps then work out how long you want to run this equipment in hours, then you can work out what size battery you will need to run your equipment for that time. The power packs have their place, I have two 12 volt 17 ah Power tech ones I use them for the USB ports and the lighter sockets. I also have a 65ah deep cycle as well and even then I can run short of power. I got caught out when I set my system up I forgot to add my computer, it draws 65amps on its own. Hope this helps, I would forget about the 7ah it wont last long, it could jump start your car if needed. Robert