Powetanks

[KathGarvey]

Hi Stargazers

Maybe a dumb question, but can I run my Laptop off the Celestron powertank,

Also would I be better getting the larger Powertank, or would the smaller one be adequate. I am trying to pluck up the courage to click the buy button for a CPC800

Regards

Kath

[gary1968]

I bought a power supply for my lappy, pugs into the power tank and steps the voltage up to 19v for the lappy. I found that when I use it it draws that much power for the computer the the goto mount loses alignment. My power tak is home made though and has a 17Ah battery but I would have thought that would have been enough for a wee while.

Now the power tank only runs the mount and the dew controller. The lappy's time gets limited to its own internal battey until I find another way to power it.

Hope that helps, oh and by the way, click the button - you know you want too...... :-D

Gary

[Helen]

Goto scopes tend to be very fussy about power drops, so I'd try and keep one power pack just for the mount. Laptops tend to suck power quickly, so it would need to be a big powerpack. One tip is to remove the laptop battery when using a power pack, that way the pack just powers the laptop rather than also charging the battery.

Helen

PS go for the CPC, you'll love it!

[KathGarvey]

Thanks Helen and Gary for your replies

It seems it will be better to get the larger Powetank to start with.

Helen do you do any long exposure photograhpy with your CPC800, as everything I read tells me i should go with the EQ mounts if i want to do long exposures.

Are there any disadvantages using the wedge on the CPC800 for long exposures.

Sorry for all the questions

Regards

Kath

[Helen]

Kath,

I've just started long exposure photography with my Nexstar 8, by putting it on a wedge (the wedge doesn't come with it). Shorter exposures are necessary without the wedge, but can still deliver good results

http://stargazerslounge.com/index.php/topic,22729.0.html

http://stargazerslounge.com/index.php/topic,22678.0.html

For just visual I would say go with an Alt Az fork mount, no contest. The Celestron GPS Alt Az models are a breeze to set up (they do the hard bits for you!). You plonk it down, switch it on, let it do its bits and then just centre a few stars and you're away. Alt Az is also far more intuative when moving the scope - so if you choose not to use the goto its still easy to direct the scope where you want to go. The eyepiece also always stays in a convenient place!

You'll need an equatorial mount of some description though if you want to do really long exposure photography. You can convert the CPC to EQ by adding a wedge, but unless you have a permanently mounted scope I wouldn't really recommend this. A proper wedge is really heavy (I can barely pick mine up, let alone carry it any distance, or lift it up onto a tripod), and it also adds to the height you need to lift the scope to get it on the tripod.

The other alternative is a scope on a german equatorial mount (the ones with the bar and counterweights). Disadvantages are: less intuative, more set up time (although you get used to this), can be heavy, eyepiece can be in odd positions. Advatages are: movable in bits, can use different scopes.

Depends what you see as your long tem needs really...

You're welcome to come and look at my scopes if you want( I'm in South Wales)

Helen

[KathGarvey]

Thanks Helens for your advice. I will take stock and think about it for a few days before I decide. It would mostly be staying in my garden, and if i where to take out into the country I would have to rope one of my sons's in. Luckily my eldest is interested in astronomy too.

Having a look at your scopes would be great, but i am a bit far off in the North of England. I do love Wales though, my youngest sister was born there and we lived in Pembrokeshire for about 6 years, when i was in my teens, oh so long ago

Regards

Kath

[blinky]

I would suggest getting something big like a car battery if you want to power a laptop with it. My 17Ah battery lasted about 40mins when powering the laptop

[James]

My laptop chews up about 5 amps from a 12V supply. I run it off a 113AH deep cycle battery so I can get a nights use without any problems especially if I let the laptop do 2-3 hours on it's own battery.

Bear in mind that most lead acid batteries (the PowerTanks are lead acid) don't like being drained all that far. Drain it by 70% for example and you are shortening its lifespan so a big deep cycle battery would be a good idea.

Having used a 113AH and an 86AH I'd suggest you consider the 86AH - it's a lot easier to carry

James

James