Cg5 and celestron 7amps powertank
Posted 05 November 2012 - 07:28 AM
Posted 05 November 2012 - 07:38 AM
Posted 05 November 2012 - 11:19 PM
Posted 06 November 2012 - 12:39 AM
Posted 06 November 2012 - 12:24 PM
You can estimate your mounts run time rather easily. The average current draw from my CG-5 is about 1.5 Amps, although this numbers a bit high but I'm assuming you're doing a good amount of slewing. So a 7Ah battery will operate around 4.5 hours roughly. Taking into account battery life and you never want to completely discharge a lead acid battery you're looking at around 3.5 hours.
Posted 06 November 2012 - 03:22 PM
Posted 08 November 2012 - 01:15 AM
I use two 105 Ah deep cycle batteries in the field and will probably add a third one dedicated to the mount alone.
Just a thought.
Edit: I found a 18Ah 12V Battery for about $35 on Amazon. Should work fine for most smaller mounts and for my Mach1.
Posted 08 November 2012 - 09:43 PM
Posted 09 November 2012 - 12:11 PM
Posted 03 September 2013 - 08:46 AM
Posted 03 September 2013 - 08:58 AM
A 7AH power tank seems to work handily, and it can have it's battery replaced and return to service at half the cost of a new one. I did this with one powertank and one of the Orion version.
What I have not been able to get to work, and I don't know why, is plugging in a USB car charger to be able to run mobile stuff off of a powertank on non-astronomy nights. Insufficient battery power?
40 ah to run the Mach 1 one night? Never heard that.
Posted 03 September 2013 - 03:45 PM
Slewing both motors at top speed, the mount draws about .71 amps.
I use a 10 battery pack of Eneloop 2500ma rechargeable AA batteries, and I get about 3 to 4 hours of run time if I am not doing long, across the meridian slews every time.
In a normal session, I will do maybe 2 hours and maybe 30 slews, but I tend to work "Linearly" with my observing, moving short distances for each slew and this pack has never let me down.
I run my XX12G Go-To dob for about the same amount of time, and the 8SE also, so to me, it does not seem like the CG5 is less efficient than these other mounts. All will run several hours if you are efficient with your slewing.
All of them measure pretty closely on current draw, with .3 to .35 amps for tracking, and .7 to .8 amps for slewing.
I also made a cable with two 9Vdc type connectors so I can either double up my pack for over twice the run time, or I can hot-swap out... Put in a second pack in parallel to the first and pull out the first pack. The mount never stops or looses settings.
Lots of people told me that this did not work and I could only run 21minutes or something, but I had been using this and was happy enough with it as a solution. I don't observe all night though, so I would not suggest that this is a solution for marathon events.
For "Grab and Go" type observing of 2-3 hours though, it has been working quite well for me personally. I have not hooked up to a house or car battery since doing this.
With the hot swap, I could run for days if I wanted. I have a 12 position charger and the batteries charge at 1 amp, so turnaround on a pack is less than 2 hours normally, depending on how low I let the pack get. The plastic pack itself costs about $2 each ( I only have two) so you could make as many packs as you wanted, but I rarely go so long that I need to put in the second pack.
I use all rechargeables these days. The trick to making this work is use the highest quality AA pre-charged you can get. That would be Eneloop XX 2500s.
But even the Eneloop 2000s run my XX12G for a normal 2 hour session without any problem. I was out a few nights ago with the XX12 Go-To dob and did about two and a half hours on the 2000ma pack and I still had about 1/3rd capacity remaining. About 30 slews by motor. I do my across the sky slews by hand though, which of course you can't do with the CG5 or the 8SE, The motors have to run to reposition the scope. The XX12G though can be moved manually at any time to save battery. Just let go and it starts tracking again at the position you leave it. I manually slew on very long slews to about where I need to be, then Go-To for the final slew. It goes longer on a pack then the CG5, but again, most of my slews the other night were pure motor-drive Go-Tos. I only manually slew when I am moving maybe a quarter of the way across the sky.
Anyway, to answer your question, I find the run time of the CG5 to be similar to the run time of the 8SE and XX12G, so I would say that it is "typical" of mounts in this class.