Mount power options

Stephane · #1 22-10-2021, 05:18 PM

Hi all,

I’m quite surprised at how complicated it is to find information about powering mounts! Other forums have old expired links and American products… I will be getting an EQ6-R pro in December and am trying to work out what powering options I have.

The mount requires DC 11-16V, 4 amps. It comes with a cigarette lighter cable which can be plugged into a battery I guess. In the garden, I have standard 230V plug outlets. Any options for a cheap transformer? Or better to buy a battery for the cigarette lighter? Please excuse my use of the word “cheap”; I do realize nothing is cheap when it comes to astrophotography. Any advice at all is appreciated.

Many thanks,
Stéphane

AdamJL · #2 22-10-2021, 05:51 PM

Hi Stéphane

This one gets asked a lot. You'll get lots of different answers, and budgets.

My portable solution:

Primary - Jackery Explorer 240
This is a lithium ion battery (not LiFEPO4 cells) that has a pure sine-wave inverter as well which means I can use plugged in appliances as well. Downside is the capacity is quite small for a whole night and I have to top it up with other (secondary) batteries. See below.
Big plus to this system is it's regulated output, meaning you will get 12V minimum all the time until about 5% capacity before the unit switches off or voltage falls off a cliff. "Traditional" lead acid batteries keep their voltage high initially and start dropping quickly. They also have the issue where it's not recommended to discharge beyond 50%. Lithium can do down to "0" which isn't true 0 because of the built in BMS (Battery Management System)

Secondary - various LiFePO4 batteries at 12Ah, 15Ah and 20Ah. These, to me, are the future. I have them "naked" i.e. not in a case, and I use them to keep the Jackery charged throughout the night. LiFePO4 cells don't need to be regulated. They pretty much keep their voltage all the way to about 10%. They also allow a LOT more charge/discharge cycles, in the thousands (compared to the Jackery which is about 500 cycles)

In the future, I'll be getting a Bluetti EB55 or EB70 when they come on sale in the next couple of months locally. This combines the best of both worlds; Jackery portability and usability with extra features and LiFePO4 technology.

Don't forget, one of the biggest pros to lithium: weight. Check for yourself the difference in lead acid vs a LiFePO4 battery.

Mains power

For power at home, I use a simple unit from Jaycar
https://www.jaycar.com.au/12vdc-7-5a...ocket/p/MP3575

I've also got a 10A unit, but found that it was unable to supply 12V (kept pushing out 11.8 or thereabouts) so some of my gear stopped working. I need to get this replaced; maybe I just had a dud.

Now I know I just typed a lot there, and you've only asked for power to the mount. I've included all the above so you can think about powering other gear as well

If all you want to do is power the mount with a battery, Talentcell make some great portable 12V batteries and sell on Amazon. I have one for my AZGTI (thanks Lewis!) and it works a treat. You'll just need a cable for the EQ6-6. Sidereal Trading in Melbs sell a Pegasus cable that outputs from a DC plug to the EQ6-R.
I might try and test it on the EQ6-R one day as well
https://www.amazon.com.au/Talentcell.../dp/B00ME3ZH7C

Startrek (Martin) · #3 22-10-2021, 06:08 PM

Hi Stephane,
I’m sure I sent you the info on what to power the EQ6-R mount whilst mains power is available ( either at home or elsewhere)
Exactly what Adam suggested
Powertech 12V 7.5 amp Power adapter available from Jaycar or Bintel
I’ve used these power supplies for years and years on both of my EQ6-R mounts and not one has failed yet.

Cheers
Martin

Stephane · #4 22-10-2021, 06:11 PM

Thanks Adam! I just remembered that I have a gentrax generator which I never use. Might make a good portable solution? It’s supposed to be “very quiet”, but still has an annoying hum. Unfortunately, it also gobbles petrol like an army tank lol. Not ideal, but I guess if I already have it, I could use it.

Thanks,
Stéphane

Stephane · #5 22-10-2021, 06:12 PM

Hi Martin, I will double check. I’ve read those files several times but must have not taken note. I will definitely look into those options. Thanks!

EDIT: just looked that option up. It’s perfect. I will purchase the Powertech 12V 7.5A. You did send that Martin. Apologies, must have been an overload of info for me to process. Thanks again.

Regards,
Stéphane

Stephane · #6 27-10-2021, 02:23 PM

Thanks all for your help. I went for the highly recommended 12VDC 7.5A Power adapter.

Regards,
Stéphane

Wilsil (Wilco) · #7 27-10-2021, 02:33 PM

Got something similar from Dometic, works perfectly from home.

The_bluester (Paul) · #8 28-10-2021, 10:48 AM

My only concern is I really dislike lighter socket power connections. I consider them unreliable, I had a few instances of very minor bumps disconnecting my visual gear in the past so for all my imaging setup I use DT connectors. They are automotive spec connectors and I am yet to have an accidental disconnection (They latch and do so with an audible and tactile click so you can connect them in the dark) out of hundreds of connectors I used in my track car and the ones in my imaging gear I have not had any failures yet.

The only advantage I see in lighter sockets personally is that they are so common you can just about get them at the supermarket.

mura_gadi (Steve) · #9 28-10-2021, 05:23 PM

What about UPS? They turn up fairly cheaply and offer a lot of power connection types, but I never see them listed as options. Sine wave etc are all excellent due to the nature of the system.

They retail cheaply and turn up regularly at auctions/sales at bargain prices and are available in a range of Ah. (The one pictured even has a DB9 plug... that is some serious old school connections...)

luka · #10 29-10-2021, 08:32 PM

Quote:

Originally Posted by mura_gadi

What about UPS?

UPS is not very suitable for this application. The batteries inside are usually SLA (sealed lead-acid) and discharges (say below 50%) will reduce their life significantly (I would be surprised if they last more than 100 cycles). Even discharging them below 80% will start causing a damage to the battery.

Also the voltage conversion losses are greater as the voltage gets converted from DC to AC (in the UPS) and then back to DC.

Stephane · #11 29-10-2021, 09:09 PM

I personally was never planning on going for a UPS, but that info about the short life cycle is very interesting Luca. Thanks for pointing that out. Understanding the pros and cons of each option is gold for beginners like me.

I am very happy I went for the Powertech option as I've heard of many using it with excellent reliability.

Many thanks,
Stéphane

mura_gadi (Steve) · #12 31-10-2021, 11:22 AM

Sorry Stephane wasn't meaning to hi-jack the link. I was interested in knowing the why nots though...

Although it seems that changing the battery type out will fix a lot of the stated problems, what you can replace it with will depend on the battery bay inside the unit...

But I did like the idea of having com's ports and several power type outlets available, that and I have good access to ex-government sales in Canberra.

More of a glorified battery box at the end of the day.

Ps. Just checked youtube and someone has been there and done that already. Nice sup'd up ups...

$80-100 for a 2nd hand UPS about the same for parts and batteries at a guess. I would stack a fan between my batteries packs before adding another cell layer, but, I am a bit bias against li-ion.

https://www.youtube.com/watch?v=fXXGhgvwCtQ (part two)

Might be something to think about with the newer Al-ion coming online soon(2024?) it would make the "awesome" setup... a lot safer(you can swallow a Al-ion battery), no operating temps as per Li-ion, three times the power and incredible recharging times.