Will this battery work for my motor drive/GOTO on my first set-up that I just ordered?

[Simonator]

Hi,

After months of deliberation, I've finally taken the plunge and ordered my first set up, which is on its way to me now. EXCITED!

I've opted for a Skymax 127, on an EQ3 mount, with Synscan GOTO. I've additionally ordered a 7mm Televue Nagler (which should give me 214x magnification and an 82 degree AFOV)... Hopefully this will be a pretty sweet starter kit!

http://www.firstlightoptics.com/maksutov/skywatcher-skymax-127-eq3-2.html

All of this was bought second hand, so I think I've got a tasty deal on it all too.

Now, I need to get myself a battery pack to drive my GOTO & motor drive...

There is the obvious branded 'Power Tank' option, or a DIY car battery jobby.... But I'm currently leaning towards one of these from Amazon-

http://www.amazon.co.uk/gp/product/B00CSI4E04/ref=ox_sc_sfl_title_2?ie=UTF8&psc=1&smid=AJUR3R8UN71M4

* Cheaper than branded Power Tanks

* Way less ugly than branded Power Tanks

* More than double the capacity of the branded Power Tanks

* More elegant than a DIY soldered solution

... From all I can tell, this seems like it should be fine... It has a DC output at 12v... So I figure it's just a matter of then ensuring that I get the correct sized cable.

But I wanted to check with you more knowledgeable folk... Do you think this will work? Am I overlooking anything? Are there any better solutions?

Many thanks!!

Simon

[Cornelius Varley]

The output seems to be 12v 1.5amp which may be insufficient to allow the mount to perform correctly. You need a psu with a 12V 2amp output (minimum) or deep cycle leisure battery.

[ronin]

Find the ampage required when slewing. The power pack say 12v 1.5A, not sure if 1.5A will be adaquate when at max rate.

Seems sort of boarder line to my thinking, would have prefered to have seen 2.5A at 12V.

Possible safety option is to set the max slew rate to a bit lower if this is possible, it would cause less current to be drawn hopefully.

[Simonator]

Thanks for your replies!

I'm not entirely clear on what this means though... Ronin, are you saying you think it will be okay at slower slew rates? Will that be fine for all tracking purposes, but just not giving me max speed for moving between targets?

Is this just a really bad idea and I should go for the branded Power Tanks?

Cheers!

[Simonator]

I found this- http://www.madpc.co.uk/~peterv/astroplover/equipnbits/EQ3.htm

'Power usage is approximately 100 milliamps when tracking and 500 milliamps (1/2 amp) when slewing at full speed with both motors running. The supplied battery pack holder takes 10 AA size batteries. So with NiMH batteries of around 1500 mAH capacity, a long night's observing would be accommodated without recharging the batteries.'

... But I think that's from a DIY GOTO system, yet driving the same mount.

[davefrance]

I power my HEQ5 with a LUCAS LSLC22-12 12v 22A AGM cyclic battery. Costs less, weighs less and lasts longer than dedicated Powertanks and is AGM rather than the normal Lead Acid. You would need to attach cigar lighter socket so make sure the polarity is correct.

http://thebatteryshop.co.uk/lucas-lslc22-12g-golf-battery-12v-22ah-5101-p.asp

[Simonator]

I power my HEQ5 with a LUCAS LSLC22-12 12v 22A AGM cyclic battery. Costs less, weighs less and lasts longer than dedicated Powertanks and is AGM rather than the normal Lead Acid. You would need to attach cigar lighter socket so make sure the polarity is correct.

http://thebatteryshop.co.uk/lucas-lslc22-12g-golf-battery-12v-22ah-5101-p.asp

Okay... I think I'm going to go down this route. Particularly since what I've purchased is actually coming with a cigarette socket power lead to the motor.

I'll buy a cigarette socket and solder it to the battery contacts. Then buy a seperate charger for it.

The only thing is though, that battery you linked seems rather on the large side at 7kg... Since I'm already going to need to carry the rest of my kit (no car, living in central London, mostly using this kit in Hyde Park, on foot).

... Would this battery work the same (only with fewer amphours)?

http://www.ebay.co.uk/itm/Lucas-12V-7AH-Sealed-Rechargeable-Battery-Security-Alarm-Burglar-Alarm-/200940050760?pt=UK_Burglar_Alarms&hash=item2ec8f5d948

... I can't seem to see the specs of the ampage, in either this one, OR the one you linked to (?????)... I'm assuming it will work though.

Cheers.

[Simonator]

EDIT:

New plan is for this battery:
http://www.ebay.co.uk/itm/200982952371

And this cigarette adapter (though I will strip off the crocodile clips and hard-solder it to prevent mistakes in the dark):
http://www.ebay.co.uk/itm/350886199371

... That should work........... RIGHT?????

Thanks!
 

[davefrance]

Okay... I think I'm going to go down this route. Particularly since what I've purchased is actually coming with a cigarette socket power lead to the motor.

I'll buy a cigarette socket and solder it to the battery contacts. Then buy a seperate charger for it.

The only thing is though, that battery you linked seems rather on the large side at 7kg... Since I'm already going to need to carry the rest of my kit (no car, living in central London, mostly using this kit in Hyde Park, on foot).

... Would this battery work the same (only with fewer amphours)?

http://www.ebay.co.uk/itm/Lucas-12V-7AH-Sealed-Rechargeable-Battery-Security-Alarm-Burglar-Alarm-/200940050760?pt=UK_Burglar_Alarms&hash=item2ec8f5d948

... I can't seem to see the specs of the ampage, in either this one, OR the one you linked to (?????)... I'm assuming it will work though.

Cheers.

Hi, I am no battery expert but I would think you are right. Perhaps some more knowledgeable members could confirm. The Skywalker/Celestron Powerpacks are 7ah or 17ah. I've read the former will last a few hours just powering a mount and the latter a couple of nights. I was put off both by cost (twice the price in France) and many reports of dead batteries. I chose the 22ah so that I had no worries with it dying on me mid session.  I can carry it with one hand but would not want to lug it across Hyde Park so appreciate your thoughts. I have had a Lucas AGM battery in my caravan for years and have found it excellent.

With regard to charger I found a small trickle charger in Halfords that specifies suitable for NORMAL,GEL and  AGM  cyclic batteries. It will not overcharge as automatic and can be left connected. Streetwize Car and Motorcycle 12V 1.5 amp autotrickle charger. Works well with my battery. Cannot find on Halfords web site but fond on Homebase http://www.homebase.co.uk/webapp/wcs/stores/servlet/ProductDisplay?langId=110&storeId=10151&partNumber=090515&c_3=3%7Ccat_26036006%7CCar+Maintenance%7C14418747&c_2=2%7Ccat_16849255%7CCar+and+Travel%7C26036006&c_1=1%7Ccategory_root%7CGarden+and+Outdoors%7C16849255&c_4=4%7Ccat_14418747%7CCar+Battery+Chargers%7C14418754&cmpid=summit_pla&_$ja=cgid:8447637736|tsid:49590|cid:275138056|lid:59204633896|nw:g|crid:30324392296|rnd:1055460821757374370|dvc:c|adp:1o4

[davefrance]

EDIT:

New plan is for this battery:

http://www.ebay.co.uk/itm/200982952371

And this cigarette adapter (though I will strip off the crocodile clips and hard-solder it to prevent mistakes in the dark):

http://www.ebay.co.uk/itm/350886199371

... That should work........... RIGHT?????

Thanks!

I think you can get the battery cheaper if you shop around. Just make sure the battery cigarette lighter socket is connected to the battery for the right polarity to the mount.

[haitch]

I just ordered one of these to play with...

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=400584675790

Given a 22Ah can cost ££££s it seems too cheap to believe but also cheap enough to chance it.

[Simonator]

I just ordered one of these to play with...

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=400584675790

Given a 22Ah can cost ££££s it seems too cheap to believe but also cheap enough to chance it.

I just ordered one of these to play with...

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=400584675790

Given a 22Ah can cost ££££s it seems too cheap to believe but also cheap enough to chance it.

WHOA.... That looks great... If it works... But I can't wait for two weeks to use my new scope!!

Do you know if that is the correct sized male socket to go into the synscan units??... Or if not, what options there are for adapters?

[stevend]

fwiw I use a rechargeable car battery jump starter that I bought from Amazon for <£30. It does the job well and has come in handy a couple of times with my son's car.

[davefrance]

fwiw I use a rechargeable car battery jump starter that I bought from Amazon for <£30. It does the job well and has come in handy a couple of times with my son's car.

I am sure it does and I wouldn't want to knock it.  However, car batteries are not designed for cyclic use only short bursts of power. I presume a car jump starter would contain the same type of battery. Personally I would choose a deep cyclic battery over a car type battery to run my equipment for sustained power over a long period.

[stevend]

Personally I would choose a deep cyclic battery over a car type battery to run my equipment for sustained power over a long period.

I guess it depends on what equipment you have, but it works for me on 6 hour sessions (and longer if required) for myself and I have never had any problems with it. Just giving the OP another option.

[mitchelln]

I have that EasyAcc for charging my tablet. I tried it on my scope for a laugh and it does not have enough grunt to drive mount motors. Its short circuit protection kicks in.

I was looking at the very same CCD camera pack only today. Spooky. I might also give one a go.

A car jump start unit from Halfords is the easiest way to go.

[Phil Fargaze]

Don't forget your future self might have cameras, laptops, dew straps, hair dryers or whatever else requiring a source of power when you are observing so if you can invest in a battery with a decent amp hour figure you might not need to upgrade in the future. I know they are not ideal for reasons stated but I have been using a car battery without any problems for quite a few years now. I run my HEQ5, laptop, camera and sometimes a dew strap off it for a good many hours. Although this is only on camping trips not full time use.

[davefrance]

If you are using or considering using a car type battery to power your equipment DON'T forget to keep it well charged. CAR BATTERIES CANNOT TOLERATE BEING FULLY DISCHARGED whereas leisure batteries can. The difference is in the thickness of the plates.  Thicker plates as in a leisure battery release energy more slowly and will not suffer the same level of destruction via sulphation. This means that a leisure battery can stand being fully dis-charged and will ultimately power your equipemt for a good deal longer before needing replacing. Just do a search on comments for failure of Power tanks due to failure to recharge after use.

[Simonator]

FWIW, I went with a 12AH Lucas 12v battery... Going to hard wire a female cigarette lighter port to it's contacts.

Thanks for all the advice!

[davefrance]

Hope you have many hours stargazing with it.