How to power a GoTo?

[Tizaporx]

Hi!

the last few weeks I've been thinking about buying a new telescope, that I can take with me on holidays too. So it can't be too big, I found a telescope that I like, which is the Celestron nexstar 4SE. I never had a goto before, so I'm wondering, how do you power these? I've heard you can power them with a powertank, but I don't know which to buy, and If I still need other cables. Thanks in advance!

[Bizibilder]

Don't bother with a powertank as they are ridiculously overpriced!!  For the same money you can buy a leisure battery and charger.  These are the batteries used for boats and caravans.  they are designed for slow discharge as you get when powering a mount.  The downside is that they are quite heavy so you have to choose carefully.  If you are only powering a mount then a smaller capacity (40Ah is the smallest, I think) one will do.  40Ah means that the battery will supply 1 Amp for 40 hours (or 2 Amps for twenty hours!) and is a measure of their capacity.  You need to be aware that you should never fully discharge one of these batteries and the rule of thumb is to stay within half of the full capacity.  ie use 1 Amp for a maximum of 20 hours - more than enough for a nights observing!!

[ronin]

Batteries are one option, not actually too bad as long as the idea is to go viewing for a short time (about an hour) - you raid somewhere like Poundland and stock up. NOT RECHARGEABLES.

Powertanks are another, the catch is they are small lead-acid batteries and if drained they get damaged internally and so do not operate well anymore. Draining on one of those seems to be sort of half way down which is too easy to do.

Your own build would be a small leisure battery and a suitable charger - try Maplins. Takes a bit more but they last.

Next is something like the Tracer Li batteries from FLO etc, they are not exactly inexpensive but are a good option, you can charge them from the car as well so you use it, plug it in and drive around on holiday then it is ready to use in the evening.

If the car is always around then get a cable to poewer from the car. I use the rear power socket in my car and stand the scope at the rear. The car battery being much bigger is unaffected by the scope. Again Maplins do a connector.

[Tizaporx]

Thank you, I've also found this https://www.astromarket.org/accessoires/stroomvoorziening/15-amp-power-supply would that cable be good enough too?

[Astro_Baby]

The Nexstar 4SE can run off AA batteries which it holds in a compartment on the mount.  Warning here is that it wont like rechargeables and it will eat batteries very fast and even more so if its cold.  The more slewing you do the faster it will consume the batteries.  I stopped using the battery approach with my Nexstar and went to a battery box but the problem with that is it reduces portability.

I bought the Nexstar as a portable rig for the nights when I couldn't be bothered to set up the bigger scope BUT what I found was by the time you factored in the scope and mount, its tripod, power tank, eyepiece case, dew shield etc etc it wasnt much less hassle than taking a big scope so it ended up being redundant.

Its also bigger than you may think looking at pics so if you are thinking of foreign hols on a plane you should really look at one first because you may be surprised at how large and heavy it actually is.

[Tinker1947]

If you plan on carrying the scope/mount any distance the a Tracer would be better there light weight have good power reserves and a power level indicator, come with a mains charger, car charger and connector lead a 14Ah does my 300P Dob for a couple of evenings.......

http://www.firstlightoptics.com/batteries-powerpacks/tracer-12v-14ah-lithium-polymer-battery-pack.html

[Tizaporx]

Thanks for the fast replies, well I can actually choose, I got a 90mm refractor that I actually could take with me on trips, so I'm thinking.. should I buy a nexstar or a dobsonian for at home? Since I got no big scope at home.. What would you do?

[Tinker1947]

Thanks for the fast replies, well I can actually choose, I got a 90mm refractor that I actually could take with me on trips, so I'm thinking.. should I buy a nexstar or a dobsonian for at home? Since I got no big scope at home.. What would you do?

Start another thread on the new topic...

[ACross]

I bought a portable power charger from Halfords in their January sale for £25. Does the job well but their prices have since gone up:

http://www.halfords.com/motoring/breakdown-emergency/jump-leads/phaze-4-in-1-jump-starter

[Michael11]

You can also try a lithium ion 9600mAh 12v battery from ebay. they are cheap (about 40$) and come with a wall charger. I guess the real capacity will be about 6000mAh, but for your scope it should be enogh. I've been using such battery with EQ6, enough for about 6 hours.

[Grogfish]

I've got a Nexstar 4 too, and been down a similar route to ACross, by buying a jump starter with a 12v car socket output. That's worked well for me over the past three years or so. One advantage of the jump starter is that it's a neat weather proof package with a handle, which I find handy compared to a raw battery.

There's currently this one in Maplin for £35 - which looks like it's the updated version of what I've got:

http://www.maplin.co.uk/p/compact-jump-starter-300a-150psi-compressor-n21kj

I got a power cable from Sherwoods Photo, but I'm sure most companies would sell one (or probably even Amazon these days!).

Enjoy your Nexstar!