Power banks?

garymck (Gary) · #1 14-09-2022, 08:35 AM

Hi,
looking to get some sort of lightweight battery pack to power my new AZGTI, and ASI533. There seem to be a lot on the market, but I'm wondering about the accuracy of the capacity claims. I have batteries for my electric RC planes that are 4000ma, and they seem to to be WAY larger than power banks that claim 10,000ma capacity. How realistic are the capacities advertised?

If you have used a power bank and can recommend one plese let me know your experience...

TIA
Gary

AdamJL · #2 14-09-2022, 10:07 AM

Hello Gary.

I use a Talentcell one for my AZ-GTi (that came with it when I purchased it second hand). They get some good feedback on Cloudy Nights as well; very reliable.

Similar to this (could very well be the same one, but it's upstairs and I'm in a meeting... so I can't go check

)

https://www.amazon.com.au/Talentcell...dp/B00ME3ZH7C/

Crater101 (Warren) · #3 14-09-2022, 03:21 PM

I have the Bluetti EB55
https://www.bluettipower.com.au/prod...-power-station
and I've found it fantastic. It needs something underneath it if the ground is damp, and it takes a long time to charge from near flat, but overall it's a fine unit, and I'd recommend it.

garymck (Gary) · #4 14-09-2022, 04:38 PM

Thanks guys for the links - the BLUETTI EB55 looks fabulous but a bit rich for my blood (and bank account!!) The Talentcell is more my price range...
cheers
Gary

Icearcher (Chris) · #5 14-09-2022, 08:48 PM

I have had this little beast from Jaycar for a few years now and its done well, plenty of USB ports and also 12volt outlet, 155Wh battery, light and pretty compact.

https://www.jaycar.com.au/portable-1...splay/p/MB3749

gaseous (Patrick) · #6 15-09-2022, 01:24 PM

Quote:

Originally Posted by Icearcher

I have had this little beast from Jaycar for a few years now and its done well, plenty of USB ports and also 12volt outlet, 155Wh battery, light and pretty compact.

https://www.jaycar.com.au/portable-1...splay/p/MB3749

I've got basically the same model, and it works very well. Admittedly I'm only running a goto scope and occasional dew heaters for visual stuff, but after 6-7 hours of use it's rarely even gone down one bar of battery life. Very lightweight too, so it's easy to plonk on both the 8" and 20" dobs without a problem.

Camelopardalis (Dunk) · #7 15-09-2022, 06:29 PM

Gary, as with all things, the devil is in the detail.

Many of the lithium based power banks quote power at native voltage for lithium cells around 3.7V, whereas for astro we usually need 12V or so.

AGM type batteries are a lot more cost effective, but heavier. For example, Jaycar’s 26Ah 12V AGM battery is over 8kg, whereas their 25Ah 12.8V Lithium battery is 3kg. The AGM battery is $129, the lithium $299…

There are other factors to consider though…lithium batteries can typically be discharged further without permanent damage, so more of that total capacity is usable.

The crux of it is how much power you actually need to carry. The AZ-GTi wont consume much while tracking, so your main power draw will be your camera cooler. During summer months, that may be as much as 2-3A per hour. You could compromise on this since most modern sensors (including the 533) really don’t need to be cooled like mad like previous generations. Cooling to 5C is sufficient in most cases.

I’d suggest setting up your rig and measuring the current consumed. Then just multiply by the number of hours you wish to image for, and add a little extra for good measure

DarkArts · #8 15-09-2022, 06:50 PM

+1 for measuring and calculating what you need at each voltage.

I bought myself a large-ish (576Wh) Li-Ion power pack not just for less weight and compact dimensions but also because it was comparable in cost and durability. At my frequency of usage, it ought to last 15 years or so ... probably longer than me. I did buy it on sale, though.

The Li-Ion battery itself may be significantly more expensive per Wh, but the conversion equipment you typically need (for a full AP setup) adds further to cost, space, weight and cables.

My Li-Ion pack has 2 x 240VAC, 3 x 12V, 2 x 5V, a built in solar-charger (just add panels), 240V rapid charger, 12-16V charger and all the control and monitoring electronics, including WiFi to be (optionally) controlled remotely. And I've used all of that except the solar charger, so far.

The cost of a lead acid battery of similar usable capacity and all the controllers, chargers, adapters and cables is about the same as the Li-Ion pack (or at least it was when I did the costing).

It also comes in handy during power outages: e.g. during an outage a few months ago, it ran my fridge for 8 hours with power to spare.

Your circumstances may be different - especially since you just seem to want to drive a single modest mount - but it added up for me.

garymck (Gary) · #9 16-09-2022, 08:50 AM

Thanks for the replies Patrick Dunk and Darkarts. The Jaycar unit may be enough - found that a friend already has one and likes it very much.

I will have to check the draw of the Camera, and also perhaps a dew heater. I've never really bothered before as I have used a 100amp hour deep cycle battery. Unfortunately it is so heavy last time I moved it I buggered my back - my faiult formlifting and twisting at the same time.

TThis got me to thinking about what would the the minimum I would need for a single nights imaging on the road.

Will try some measurements today.

Cheers
Gary

garymck (Gary) · #10 16-09-2022, 10:56 AM

Just measured current - AZGTI tracking, ASIMC533 Pro cooled to -5c in a room at 18c, Raspberry Pi 4, total current 1.2 amps @12.4v . So looks like I don't need as much power as I thought. The Powertech unit looks good at the moment ...

Thankyou all
Gary

BadWolf (Stewart) · #11 16-09-2022, 12:03 PM

I recently purchased the Companion Brand Rover 40 AH Power Station from BCF. Currently listed for $529 at their "Club Price" right now. Supposedly retails normally at $800.

The unit is extremely good. It runs my Skywatcher HEQ5 Pro mount flawlessly and seems to last forever. On sidereal tracking its meter says it is drawing 8 watts, and when slewing it draws 27 watts. I am mainly visual, and a typical session for me is about 3 hours. I do a lot of slewing in that time chasing double stars all around the sky. The meter on the power supply says for such a session (i.e. 3 hours of viewing and slewing) the power pack only depletes by 4/5 percent. I estimate it would power the HEQR Pro just on sidereal for days and days.

Hope the link works, otherwise search BCF for Companion Rover 40 AH Power Supply.

https://www.bcf.com.au/p/companion-r...on/614922.html

Good luck,