Power supply for HEQ5 pro mount.

[batema]

Hi,

We have a Celestron Power Tank 17 (250amp engine starter) that we bought when we got our mount. I find that after about 4 hours of continual running for our HEQ5 that the light flashers to indicate low power source level and rapidly fashers shortly after. Could anyone suggest an alternate power supply that could run from the household supply. It is frustrating with fine weather to start on a new object to run out of power. However during a work night maybe the running out of power is a good thing....
Thanks Mark B

[Kokatha man]

I know nothing about this particular Celestron unit Mark: the stated "250 amp engine starter" suggests to me it is on a par with the ***amp jumpstarter jobs from auto shops like Sprint or Supercheap etc: which are every bit as functional and far cheaper to buy (from what I've heard about the prices they slug for these so-called "specialized" units such as your Celestron power supply.)

Without getting too deep on battery ratings; cars use lead-acid batteries (both types mentioned above being SLA's - sealed lead acid) and are rated in CCA instead of Ah - "cranking capacity in amps" as opposed to the original time-rated "amp-hourage."

With the unit I recently bought from Sprint Auto for $60-$70 it is marked as "900 amp jumpstarter 17Ah" - this rating almost certainly suggests your 250 amp job to be actually a battery of no more than approx. 5-7Ah, far too small for the HEQ5!

This is why you only get a couple of hours useage with your HEQ5 Pro. I have this mount also, and my unit will run it all night; though it is best to put it back on charge after this amount of time: but it absolutely leaves your power unit for dead!

You have a flashing LED to warn of low terminal voltage on the Celestron, whereas mine has an inbuilt voltmeter: there is another thread around at the moment that talks about regulated power supplies and batteries, worth reading on this subject.

Essentially, I'd thoroughly recommend one of the units such as my own for portability - but if you go the 240 mains to 12 volt DC power supply path make sure whatever you purchase is a regulated output supply and can deliver several amps of current.

Cheers, Darryl.

[[1ponders]]

Perfect timing Mark. Check out this thread on Regulated Power supplies that has been running this week.
http://www.iceinspace.com.au/forum/showthread.php?t=30555

[ozstockman]

Hi Mark,

I bought GMC power tank from Bunnings for something like $40 a year ago and it works excellent for my EQ6 Pro mount.

I have never seen it run out of charge completely. Even after 6 hours of operation it still shows 50% of charge left. I guess Bunnings still sells them. At least I saw one there a month ago.

cheers,

Michael