Powering my EQ6 Pro from battery ??

[Newbie79 (Matt)]

Hi all,

I have been looking at purchasing a battery pack to power my EQ6 Pro (when it arrives). All the ones I have looked at have been 12v but range from 900 - 1200 - 1500 amp.

What difference do the amps make. Would I fry my mount by using a 1500 amp battery pack. The one I have been looking at is

http://http://www.projecta.com.au/catalogue/cid/25/asset_id/59

Any help /advice would be appreciated

Thanks Matt

[Merlin66 (Ken)]

You're probably reading the Ah capacity of the batteries ie the Amps x hours before discharge.
The battery will only gives the Amps needed by the mounting - around 2A.
The big "truck" batteries are a PITA, and quite a load to lug around, as well as the possible problems with acid leak..

I'm using successfully a collection of 20Ah gel cell batteries and a electronic charger, I also use one of those car computer transformers ( 160W) which gives 15V from 12V input. This gives enough voltage to get good slewing etc.
The EQ mount is OK at 15V.
Hope this helps

[sheeny (Al)]

G'Day Matt,

I assume you have been looking at jump starter packs from your description.

First of all... you won't fry your mount. The biggest risk you'll face will be "frying" the battery. Jump starter packs are designed to start engines, so they have a "cranking battery" in them. The amp figures you have been looking at relate to the starting current they can supply when cranking a starter motor. To start a diesel engine you need a battery with a larger cranking current.

Cranking batteries really don't like being discharged a long way, deep cycle batteries are better for that. Deep cycle batteries are a better choice for powering your scope, but they are probably not as conveniently packaged and probably not as cheap.

If you aren't going to invest in a deep cycle battery, then buy the biggest jump starter pack you can afford. The bigger it is, then generally the less you will draw it down each session... the less charge you draw out of it each time the longer it will last (in very crude terms).

Having said that, I've had my CG5 mount for 4 years or so, and I've run it from a 7AH Celestron Power Tank, and as far as I can tell the EQ6 and the CG5 have similar power requirements. 7AH is not a big battery, but the mount does not draw a lot if current usually. In the same time I have cooked two jump starter packs because I was drawing them too low trying to drive my dew heaters and laptop (off separate jump starter packs - dew heaters 24AH, and laptop 38AH). I haven't had my power tank apart to see if it has a deep cycle battery in it, or a cranking battery. If it is deep cycle then that might explain why its still going...

These days I have a 108 AH deep cycle battery in the obs, with a solar trickle charger and and electronic charger of mains to boost it up after use.

Al.

[Newbie79 (Matt)]

Thanks for your replies so far

Is there a way to work out approx how long a particular battery will last. The one I have been looking at is 24AH. The manual for the jump starter says to charge it once it gets to 50%.

How long could I run the EQ6 before I needed to charge again. Would i get a couple of hours out of it?

Matt

[mithrandir (Andrew)]

The other question you should ask yourself is whether you want to run anything else. As Al was alluding, running anything else off the same pack will severely limit the time available. I have a Celestron 7AH too, and running an ASGT mount plus a laptop gives me about an hour before the voltage drop causes the mount to stop working.

I have an isolated dual battery in the diesel 4WD. I've recently replaced a 130AH deep cycle battery with a marine one for about $190. (I can use if for starting the car if I have to. You can't do that with a deep cycle battery - the cranking current could destroy it.) It keeps the mount, laptop and CCD running longer than I'm prepared to spend outside freezing my appendages off.

Andrew

[lacad01 (Adam)]

Hi Matt, are you looking to power the mount in the field or at home? If the latter, I'd recommend looking at getting a suitable DC power supply (240V AC to 12V DC) rated at 5Amps or better. There are already a few threads in this section which outline what options you have in that area.
If the former, as has been already mentioned a deep cycle marine or caravan type of battery is what you're after. I use a 75AH deep cylce for that (which I also use for camping) but I'll probably be upgrading to a larger capacity soon.
cheers

[StevenA (Steven)]

At 1st I just used a car battery and put clamps on the end of an old jack plug which happened to fit the mount. Then when I had the money I bought one of those car jump starters. It has a light, air compressor, two cig' lighter outlets, and of course the car jump leads. It holds enough power for an all nighter. I got mine from KMart for about $70.00. It's a cheap alterntive or you could buy better. They are lighter than a car battery and can be charged in the car cig' lighter or by mainss. When I am out and about I use a solar panel which plugs into one of the cig outlets to recharge it during the day. In orther words it is not nessessary to buy an expensive unit made by the companys that make the scopes. StevenA

[bmitchell82 (Brendan)]

a 100A-h will last me all night with the lappy running off a DC-AC converter for the laptop (prolly could use a DC as the eepc runs 12 volt. anyhow ) and the mount, everything else i run off batteries or the laptop power anyhow. after a full night eg from 5-6 in th eevening till 5-6 in the morning i will only just use 1/3rd or so of the battery. so a 100 ah should last a normal person with all the fruit for 2 full days without hassle.

[White Rabbit]

I've used the jump start pack since I got a powered mount, and I can tell you they are fine. I've had the same 1900amp-h battery for about 3 years and it's still going strong. I've given a good beating as well, I use them when I'm camping as power for everything and they still keep going.

I have a 600(minimum you would want IMO) 900 and a 1900.