Power Requirements for an Skywatcher HEQ5 Pro Mount and Atik One 6

[Eris]

Hi everyone,
Taking the risk that this post is too obvious I am looking to transport my Skywatcher HEQ5 Pro mount system and Atik One 6 beyond the city lights and powered up from a 12 volt deep cycle battery. I require the battery to have sufficient power to last a good night of observations with something left to spare.
Can anyone please advise me of things I need to consider before making a battery purchase?
Thanks to all who are able to offer advice.

[doppler]

Hi Eris,

I have been using standard car batteries for years without issue. Standard car batteries are not designed to be run from full charge to discharge cycles on a regular basis and this can reduce battery life. I have only found this to be the case if you don't recharge after use and leave the battery flat for a few weeks. This is a common problem with jumpstart porta packs, you have to keep these charged up.

Deep cycle batteries are designed for this purpose but are more expensive. My current portable battery is a $60 Repco standard car.

I guess it comes down to your budget and how often you are going to use it.

Rick

[raymo]

It's good to see someone else who doesn't spend a large amount of
dollars on sophisticated power supplies when their equipment doesn't
demand it. I'm in my forty third year of using car batteries, and have never had a problem. Additionally, several of those batteries cost me nothing, as they were my own well used ones that would not hold charge for more than a week or so, but were fine for use with my rig when kept charged. My current one spent six years in my Corolla, and has now spent a further three powering my rig.
raymo

[Eris]

Hi guys you have mentioned some good points, especially not to go over the top at the expense of being practical.
I just need something that will be reliable in the field. The last battery I had although I thought it was charged, failed to get the mount moving. Perhaps I should have used a voltmeter to test just how much "juice" it had before starting up.
I was told by a guy in the battery business the a battery powering a Skywatcher HEQ5 Pro could go as low as 7volts. I don't suppose you know if this is true? Thanks for your comments it is appreciated.

[raymo]

If you have a v.3 hand controller, it will tell you what voltage your battery is putting out,[ the v.4 has deleted this function, along with the ambient temperature function]. Voltage will tell you whether the battery is fully
charged, but only a load test will tell you how good the battery is.
The hand controller will function down to 7.5v, but the mount requires
11 to 15v. The red power light will start blinking when the power is approaching the minimum required voltage.
raymo

[Eris]

Thanks for that information I will check it out. Yes, I don't have fond memories of that "blinking" red light.

Just quickly on another tack, I notice that you also have an 8" scope. Does it ride on the HEQ5Pro mount? If so how does it travel?

[jakob]

I monitored my EQ5 at the last session till 2am. (~8hrs.)
Peak A=1.49
Volt min=12.32
Ah total=29.2 for the session
Wh =358
Battery Voltage at the end=12.46

I'm using a 40Ah Deep cycle battery.

But the red light was blinking all night!:mad2:
The Synscan handset Voltage reads always 1.6V less than the actual feed-in Volts.

I Hope this helps.

[doppler]

I have the Heq5 pro and have noticed that the red light flashes when slewing with a very light load ie 4" f7 refractor, but when it is under a big load ie 10" f4.8 newt the light stays solid. Maybe the flashing light also means the mount is not drawing much power?
The gears and motors are much more noisy with the lighter ota as well, but I think that I am pushing the mount a bit with a 10" newt on board LOL.

Rick

[raymo]

Eris, My 8" f/5 rides nicely as a visual scope on the HEQ5, and is fine
for astrophotography with a lightish load, such as a small guidescope
and a DSLR. I have an 80mm achro mounted on mine, along with
the original 9x50mm finder, and it handles that load just fine, but I
did have to fit an extra 0.8kg counterweight.
Jakob, The light should stay solid at all times, provided that the power cable is capable of carrying the max normally encountered load
without causing a voltage drop. The 1.6v variation doesn't mean much, as both the voltage and ambient temperature functions seem to have
always been a bit questionable.
Doppler, It is to be expected that the gears will be quieter when
using the 10", as the gears will be more firmly engaged with each other
when moving significantly more kilos. When engaged lightly they tend
to chatter slightly.
Why the red light on your mount blinks with a light load is beyond me.
Never come across that phenomenon before on any of the several
5s and 6s I've been around. They all stay solid, even when just carrying a DSLR and no counterweights.
raymo

[doppler]

Hi Raymo, My first thought was that something was not right, maybe there is a bad/loose internal electrical contact in the mount? It only ever blinks when slewing though (higher power demand?), might be time to get the screw driver out and have a bit of a look.

Rick