Supplying Power to Celestron Nexstar

[piff]

I recently bought a second-hand Celestron Nexstar 8 SE Schmidt-Cassegrain with go-to capability. In the manual it states "The Nexstar can be powered by eight AA batteries (not included) an optional 12 volt AC adaptor, or an optional  car battery adaptor."

The next few paragraphs describe exactly how to instal the batteries in the base, but rather unhelpfully there is not another word in the manual that I can find about how to provide power tot he telescope using a car battery charger, which is the method I would much prefer, rather than running through innumerable sets of batteries.  

I purchased a car battery charger especially to use with the telescope, but I cannot see for the life of me how or where to plug it in. The only input plugs I can see on the mount are of the "telephony" type, square in shape. The cable that came with the charger has a "car cigarette lighter" type of plug at one end and a tiny circular "mobile phone" type plug at the other end. Neither looks likely to fit into any visible orifice on the telescope mount.

How exactly is one meant to use a car charger to power the telescope?

[Cornelius Varley]

You need either a car battery, a deep cycle leisure battery or a jump start battery to power the mount, not a battery charger.

[Cosmic Geoff]

The power inlet is next to the power on/off switch at the bottom of the mount arm.  It is a 5.5/2.1mm socket IIRC. You need a +12v power supply or a battery pack, not a battery charger.

[Geoff Lister]

Beware.

Car battery chargers are, as their name suggests, designed to charge batteries. Their output voltage could exceed the mount's limits if they are not connected to a car battery.

[alanjgreen]

As above, beware!

The scope is NOT fused! A 10amp fuse is located inside the cigarette socket that is found on the scopes original power cable (seems to be optional on your scope according to the spec).

You MUST use this cable to add a FUSE into the circuit otherwise you may FRY THE ELECTRONICS in the scope.

This is the original celestron cable (if you need to purchase one) - 10A fuse inside cigarette socket, unscrew the end and it will drop out

https://www.firstlightoptics.com/celestron-mounts/celestron-car-battery-adaptor-for-all-nexstars.html

This is a better quality alternative - - 10A fuse inside cigarette socket, unscrew the end and it will drop out

https://www.firstlightoptics.com/astronomy-cables-leads-accessories/lynx-astro-mount-power-cable-for-celestron-mounts.html

Both of these are FUSED (10 amps) so your scope is protected against power surges.

Here are some power packs designed for the purpose of powering a scope...

https://www.firstlightoptics.com/batteries-powerpacks/skywatcher-powertank-7ah.html

https://www.firstlightoptics.com/batteries-powerpacks/skywatcher-powertank-17ah.html

HTH, Alan

[SilverAstro]

Sadly, a fuse will not protect the scope from an over voltage situation.

For a fuse to blow something needs to draw excess current, ie an already happening disaster in whatever the fuse is connected to /supplying (edit : and of course it protects the power supply if there is no fuse on the outlet socket ). Fuses do not protect the supplied equipment, they only protect the cable (up to the fused point)  that is supplying the power resulting from a fault in the supplied equipment.

[Knighty2112]

Get one of these babies. Last ages between charges, and can strap it to the telescope mount legs so you don’t trip over it outside in the dark.

https://www.firstlightoptics.com/batteries-powerpacks/celestron-lithium-lifepo4-powertank.html

[SilverAstro]

Also, it may be worth saying :- that a battery charger should not be connected to the wire that is feeding the scope. The scope wire should be connected only  to the battery terminal. The charger should be connected to the terminal of the battery by a separate wire.

Reason : if the wire to the scope becomes detached from the battery you do not want it to remain attached to the charger alone.

[Geoff Lister]

piff,

The table, below shows power consumption of my various mounts

The manual for your mount states a current of 750mA.

These are my (external) power sources, all of which should work with your mount.

Geoff

 

[Bino Pete]

I use one of these for my 8" SCT and I've been happy with it. It helped start my car once or twice over Christmas as well!!

http://www.halfords.com/workshop-tools/garage-equipment/battery-chargers-jump-starters/phaze-4-in-1-jump-starter?_br_psugg_q=jump+starter

You will need a power cable to go from your telescope to a cigarette socket like this -

https://www.firstlightoptics.com/power-accessories/celestron-car-battery-adaptor-for-all-nexstars.html

[des anderson]

Everyone`s giving good advice here. I use a 12hr Tracer battery which last`s a long, long time.....with my nextstar6 or my AVX. Des