Portable Power Supply for Astrophotography

[Jammy]

I'm looking for a portable power supply to power my astrophotography rig.

I'm wondering what everyone else uses?

I've just seen this on FLO website.  Is it any good?

https://www.firstlightoptics.com/batteries-powerpacks/powapacs-atom-pro-26ah.html

If I've worked this out correctly my 12v power consumption will be:

Equipment                          Amps
AM5 (Tracking)                   0.6
Astrozap Dew Heater         0.6
EAF                                     0.5
ASI 1600mm                      1.0
ASI 1600mm Cooler           2.0
EFW                                    0.15
ASI 290mm                         0.5
ASIair                                  5.0
        
Total                                   10.35

At 26ah, does this mean the power pack above will last 2.5 hours?  Or have I worked this out wrong?

Thanks
 

[JeremyS]

Tracer

[Jammy]

1 hour ago, JeremyS said:

Tracer

Thank you.  Which one?

[Astroscot2]

Are you sure the ASIair consumes 5 Amps?

Edited January 16, 2023 by Astroscot2

[ONIKKINEN]

The Asiair definitely wont use 5A on its own, at least not all the time, neither will the EFW, EAF or the camera cooler use that much unless you are constantly changing filters, focusing and deliberately cooling to as low as the camera will go and its very hot outside. Pretty sure you can safely at least half the expected load you calculated there.

Edited January 17, 2023 by ONIKKINEN

[Carbon Brush]

Have actually connected your rig to a power supply and measured the current draw?

Relying on worst case figures quoted from various sources is not going to be realistic.

@ONIKKINEN gives a more realistic idea. - but it ought to be measured.

 

Edited January 17, 2023 by Carbon Brush

[Jammy]

Thanks guys - I was hoping someone would say my figures were too high!  Yes, I used the info from the manufacturers details.

I've not measured the current draw.  I'm not sure what instrument I need to measure it??

[Carbon Brush]

You can use the current (AMPS) range on a multimeter, or buy a stand alone ammeter.

A multimeter is (in my opinion anyway) an important part of the astro toolkit these days.
As important as lens cleaners, collimation tools for newts, allen keys, etc.
A multimeter has many other uses around the home and car.

Just one example of the many hundreds available:

https://www.amazon.co.uk/Digital-Multimeters-Battery-Voltmeter-Electrical/dp/B07W3T2542/ref=sr_1_3_sspa?crid=10MQ03NOV69DU&keywords=ammeter+voltmeter+combined&qid=1673960163&sprefix=AMMETER%2Caps%2C104&sr=8-3-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&psc=1

[knobby]

Hi Jammy, when you do get an idea of how many Ah you'll need, pick a battery that's around 2 to 2.5 times the rating as the rating on the battery is to 'destruction' 🙂

My AGM diy jobby is rated at 14 Ah, but If I use it at around 3 Ah the voltage drops from 12.6v at the start then drops to 11.1 after about 3 hours.

Any further and the cells become damaged.

 

PS  -If you're willing to pay £299 I'll make you one 🤣

 

[knobby]

It's not that hard If you have a few tools ...

It's evolved a bit over the years, now has a 14 Ah for the mount / camera and a separate 12 Ah for the dew heaters.

[ONIKKINEN]

12 minutes ago, knobby said:

Hi Jammy, when you do get an idea of how many Ah you'll need, pick a battery that's around 2 to 2.5 times the rating as the rating on the battery is to 'destruction' 🙂

My AGM diy jobby is rated at 14 Ah, but If I use it at around 3 Ah the voltage drops from 12.6v at the start then drops to 11.1 after about 3 hours.

Any further and the cells become damaged.

 

PS  -If you're willing to pay £299 I'll make you one 🤣

 

Important to note that certain equipment doesnt like even 12v and the supply really should be at 13.6v (EQ mounts at high load and cold temps one of them).

And temperatures greatly affect how long even a good quality unregulated battery solution lasts. In sub zero temperatures you can expect 0-30min of trouble free power and at 3 hours of use you can expect to recycle the whole thing. Just something for OP to consider as its not as easy and applicable to every situatuon as it seems (bulkiness is another negative too).

[knobby]

Li-ion is usually 3.2v per cell so unless that thing is regulated in some way It's going to be pushing out  approx 12.8 v, I'll admit that 2 kg is nice and light though 👍

 

[Jammy]

6 hours ago, Carbon Brush said:

You can use the current (AMPS) range on a multimeter, or buy a stand alone ammeter.

A multimeter is (in my opinion anyway) an important part of the astro toolkit these days.
As important as lens cleaners, collimation tools for newts, allen keys, etc.
A multimeter has many other uses around the home and car.

Just one example of the many hundreds available:

https://www.amazon.co.uk/Digital-Multimeters-Battery-Voltmeter-Electrical/dp/B07W3T2542/ref=sr_1_3_sspa?crid=10MQ03NOV69DU&keywords=ammeter+voltmeter+combined&qid=1673960163&sprefix=AMMETER%2Caps%2C104&sr=8-3-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&psc=1

Thanks, I'll get one and see what the current draw actually is before I do anything else.

[Jammy]

3 hours ago, knobby said:

Hi Jammy, when you do get an idea of how many Ah you'll need, pick a battery that's around 2 to 2.5 times the rating as the rating on the battery is to 'destruction' 🙂

My AGM diy jobby is rated at 14 Ah, but If I use it at around 3 Ah the voltage drops from 12.6v at the start then drops to 11.1 after about 3 hours.

Any further and the cells become damaged.

 

PS  -If you're willing to pay £299 I'll make you one 🤣

 

Sorry, I don't know what you mean by rating.  Could you explain?  Thank you

[knobby]

The atom pro is rated at 25Ah, you need to check how many amps your equipment uses somehow.

[900SL]

On 16/01/2023 at 23:21, Jammy said:

I'm looking for a portable power supply to power my astrophotography rig.

I'm wondering what everyone else uses?

I've just seen this on FLO website.  Is it any good?

https://www.firstlightoptics.com/batteries-powerpacks/powapacs-atom-pro-26ah.html

If I've worked this out correctly my 12v power consumption will be:

Equipment                          Amps
AM5 (Tracking)                   0.6
Astrozap Dew Heater         0.6
EAF                                     0.5
ASI 1600mm                      1.0
ASI 1600mm Cooler           2.0
EFW                                    0.15
ASI 290mm                         0.5
ASIair                                  5.0
        
Total                                   10.35

At 26ah, does this mean the power pack above will last 2.5 hours?  Or have I worked this out wrong?

Thanks
 

You are closer to 4A average I'd say

EAF and EFW only draw when needed

AAP around 1A average

1600 Camera at 50% cooling 1A

Dew heater and ASI 290mm (uncooled?) 1A

Mount 1A tops say (average)

 

Allow for say 7 hrs and double for Ah capacity so 60 Ah

I use a 30 Ah sealed leisure battery in an insulated battery box, weighs around 7 kilo, can handle deeper discharge than standard lead acid batteries, I don't draw more than 3A average and it's good for 6 hours, I may add a second battery. I put it on a smart charger after each use

I also have a regulated 13.6V 10A power supply when using at home.

I feed a fused powerpole connector bar and run most everything off this. Each line is separately fused

And yes, a multimeter is the astrophotographers friend as is a good set of crimps and crimping pliers

 

 

 

 

Edited January 18, 2023 by 900SL

[900SL]

On 16/01/2023 at 23:21, Jammy said:

I'm looking for a portable power supply to power my astrophotography rig.

I'm wondering what everyone else uses?

I've just seen this on FLO website.  Is it any good?

https://www.firstlightoptics.com/batteries-powerpacks/powapacs-atom-pro-26ah.html

If I've worked this out correctly my 12v power consumption will be:

Equipment                          Amps
AM5 (Tracking)                   0.6
Astrozap Dew Heater         0.6
EAF                                     0.5
ASI 1600mm                      1.0
ASI 1600mm Cooler           2.0
EFW                                    0.15
ASI 290mm                         0.5
ASIair                                  5.0
        
Total                                   10.35

At 26ah, does this mean the power pack above will last 2.5 hours?  Or have I worked this out wrong?

Thanks
 

As a follow up, I connected a multimeter in ammeter mode to see what my set up draws.

Vixen SXD2 and Star book 10, 0.5 amp tracking average

ASI Air Pro, two dew heaters, 533MC pro 50% cooling, ASI178mm, 1.7A 

So typical 2 - 2.2A, rises by 0.5A slewing. 

[david_taurus83]

I've used some form of meter for monitoring power consumption on my kit for years and I've never known it to be drawing more than 3 amps at a time, usually cruises along at around 2amps. That's with large EQ6 mount, camera, dew heater etc. The same also with my AM5. Lithium is better, lighter and holds voltage for longer before it starts to drop but very expensive if your looking for lots of amp hours. Traditional acid battery is obviously cheaper, reliable and lots of amp hours but very heavy and voltage drop can be an issue as it discharges as the mount may start to get upset when down to 11v etc.

It depends on how portable you want it to be? Portable as in go to a dark site for a few hours? Then I'd say lithium battery of some sort. If only bringing kit out of the shed into the garden and you don't have mains supply nearby, then a traditional leisure battery would be better and cheaper as long as the weight isn't an issue. £100 would get you a decent one and a smart charger and would prob last a couple of years at least.

[EarthLife]

If you want a simple clean PSU without any hassle and are maybe not technically able (or just don't want too) to wire up things like step-up DC-DC regulators etc then something like these can be a nice alternative ..

https://www.amazon.co.uk/Domfish-Portable-Generator-Adventure-Emergency/dp/B0B78J5VY3/ref=psdc_11714761_t3_B09PR8GR14?th=1

They have sine wave 230V outputs so fine for anything that wants a mains AC supply. I guess if you're willing to spend many 100's or a thousand or two on cameras and telescopes combined then an extra £250 on a portable silent generator is not a huge cost. They can be charged from the car/van or a portable solar panel if you like telescoping while on holidays or what not.

 

If you want say a constant 14V DC (or maybe 19V for a laptop) from say a 3-cell lithium battery then the DC-DC boost convertor would do that for you, it would be a constant voltage supply up until the battery is drained. Something like one of these ..

https://www.aliexpress.com/item/1005001336156816.html

You'd also need a low battery warning sounder/indicator as well though so as not to over discharge a lithium battery.

Edited January 21, 2023 by EarthLife

[BlueAstra]

I bought one of these from Amazon for power/current measurement. It comes with bare ends so I put a power plug (male/female) on each end and just put it in series with with the dew straps for measurement.

ARCELI 150A Watt Meter Power Analyzer High Precision RC with Digital LCD Screen for voltage (V) current (A) Power (W) Charge(Ah) and Energy (Wh) Measurement

ARCELI 150A Watt Meter Power Analyzer High Precision RC with Digital LCD Screen for voltage (V) current (A) Power (W) Charge(Ah) and Energy (Wh) Measurement

[Jammy]

Thanks for the replies guys.

I checked my system with a multimeter yesterday.

The Amp draw on the system was :

2.4 Amps when idle

maximum 2.7 Amps when tracking and imaging

maximum 4.1 Amps when slewing

 

I'm now thinking that something that I could take camping as well as for astro would be good.  Nothing too heavy.

[Jammy]

Still not decided!

I think I'm going for this one:

BLUETTI EB3A Portable Power Station | 600W 268Wh

https://bluettipower.co.uk/products/bluetti-eb3a-portable-power-station

268Wh should give 22.3 Ah at 12v.

Running at roughly 3 amp that is 7 hours. 

[ONIKKINEN]

1 hour ago, Jammy said:

Still not decided!

I think I'm going for this one:

BLUETTI EB3A Portable Power Station | 600W 268Wh

https://bluettipower.co.uk/products/bluetti-eb3a-portable-power-station

268Wh should give 22.3 Ah at 12v.

Running at roughly 3 amp that is 7 hours. 

I have an Ecoflow river 300 with specs pretty much identical to this one you have linked (identical to the point that they may be the same actual battery in different clothes).

Mine has never been even close to 0 for a single night and usually could supply power for 2 or 3 before running out, not that it matters since it recharges so fast. Have used mine maybe around 100 times now and see no signs of slowing down or loss in capacity (used in -27 to +15). This will be exactly what you want for mobile AP, well worth the money!

[Jammy]

10 hours ago, ONIKKINEN said:

I have an Ecoflow river 300 with specs pretty much identical to this one you have linked (identical to the point that they may be the same actual battery in different clothes).

Mine has never been even close to 0 for a single night and usually could supply power for 2 or 3 before running out, not that it matters since it recharges so fast. Have used mine maybe around 100 times now and see no signs of slowing down or loss in capacity (used in -27 to +15). This will be exactly what you want for mobile AP, well worth the money!

I've seen a couple of people mention Ecoflow River 2 on another forum.

Is the 300 the same as this one?  https://uk.ecoflow.com/products/river-2-portable-power-station

I can't find the 300 for sale anywhere.

[ONIKKINEN]

20 minutes ago, Jammy said:

I've seen a couple of people mention Ecoflow River 2 on another forum.

Is the 300 the same as this one?  https://uk.ecoflow.com/products/river-2-portable-power-station

I can't find the 300 for sale anywhere.

Hmm, looks like my model is no longer being sold. Looks like this: https://eu.ecoflow.com/products/river-portable-power-station?variant=37254607863972

The river 2 looks like a newer version with LiFePo4 cells, i think mine has good old lithium ion (not so sure about that though). So should be an upgrade all around to mine, at least when it comes to total lifetime and overall weight which are the selling points of the fancy new LiFePo cells.

Either way something like the river or the bluetti or really anything with similar specs will work very nicely with AP kit. Should probably try and get something that is as local to you as possible as shipping batteries this big for potential warranty issues could prove to be a headache.

Edited February 6, 2023 by ONIKKINEN