Celestron VX Question

[jeff.cotter]

Hi Everyone,

I've been doing the research on the Celestron VX 9.25 and from what I've read so far, it doesn't come with a power supply (found quite a few people on the net complaining about this). The specs on the Celestron website don't make this clear one way or the other. Firstly, does anyone know if this is the case and secondly, where I can source a Celestron AC adapter (haven't had much luck finding one yet).

Thanks in advance.

[Camelopardalis]

Hi and welcome to IIS Jeff!

Can't help you with the AC adapter I'm afraid, but my AVX mount came with a power cable with a captive connector at the mount end (screws on) and "cigar lighter" plug at the other end, for connecting into any suitable 12v DC power source, such as a Celestron power tank or cheaper alternative. The power supply is not provided - and wasn't with any of the other mounts I have.

[jeff.cotter]

Thanks for the reply Camelopardalis.

So how then do you power your mount? As for cheaper alternatives, I've found some 12V power supplies with cigarette lighter outputs that I presume would do the job. But I'm concerned that I might be voiding the Celestron warranty (I saw a statement somewhere in their documentation to the effect that using a non-Celestron power supply will void the warranty).

But the power tank certainly looks good for operating out in the field. Have you had any experience with it, in particular how long you can operate on one charge, e.g. can it handle an all-night session?

[raymo]

Hi Jeff, The subject of powering mounts has been discussed on IIS many
times, with just as many preferences and opinions appearing. Many people are limited by their budget, and have to make do with what they
can afford. I have been powering my present HEQ5 Pro Goto, and my previous mount, for many years with a car battery, although purists
will recoil in horror. I only power the mount and a primary mirror dew
heater with it, but it will easily last for an 8hr session. When you consider that it ran in my car for four years before being put into semi retirement
on my scope, I imagine that a new one would do even better. Also. it's only a small battery, being out of a Corolla. A larger car battery would
obviously last even longer. You can't harm the mount; it will tell you if the voltage is low. I wouldn't worry in the least about Celestron being unhappy. Celestron owners use all sorts of power supply arrangements,
as you will see if you go to a star party.
The only proviso is that if you want to power other things as well, such as a laptop, it is wise to use a separate battery[or run it from it's
own battery and carry a spare one with you],to avoid potential ground
loop problems.
raymo

[Larryp]

Jeff, its easy and cheap to make your own. My one has a 12volt 18Ah deep cycle AGM battery you can buy on Ebay for about $50.00. I built a carry caddie complete with a cigarette lighter socket and a lidded area for storing tools, fuses and other odds and ends. All much cheaper than buying a Celestron Powertank.
Of course, you could make it to suit any size battery you choose.

[Camelopardalis]

I'm no legal expert so don't take this as a definitive answer, but given they provide the cable for the mount with a standard 12v plug then I can't see how they could enforce such a warranty policy.

Personally I'm not very electrically skilled so I got my Celestron power tank in a package with my grab-and-go scope. It's the 7Ah version and the torch function is useful and it has 2 power sockets for powering the scope and another, for example a dew heater tape. But as the other guys have mentioned, there are cheaper and more beefy solutions depending on how creative you are.

As for lasting the night...it depends on how long your sessions are :lol: my 7Ah power tank has lasted repeated 6 hour sessions of my Nexstar 8SE, the AVX and my bigger scope on the EQ6 (note: not at the same time) without the low power light coming on, so I don't really know how long it lasts.

[Stardrifter_WA]

Hi Jeff,

The Celestron Power Tank is a very nice bit of gear, BUT, and isn't there always a but, a word of warning. The charger than comes with the power tank is NOT a trickle charger and if you leave it on charge, for a long period of time, it will wreck the battery, as I found out. This apparently has been a big problem with them. However, not all is lost.

I have had both the smaller and larger 17Ah power tanks. The smaller one was fairly useless and didn't get me through the night, so I also got the 17Ah, which did the job nicely, until the battery died, due to overcharging.

I recently took it to Battery World and they replaced the battery with a 21Ah battery and added an "anderson type" plug and lead, which matched my normal charger, and bypassed the charging circuit altogether. Now it does the job really well, and I can leave it on charge. The 21Ah battery wasn't cheap though, but then it is a high quality battery. The lead and plug cost $10 and Battery World didn't charge me for any labour.

As for AC adapter, these can be brought through Jaycar, but make sure the pin is the correct polarity.

Cheers Pete

[jeff.cotter]

First, thanks for all the responses guys!

Since I made the post I have indeed found quite a bit of info on Ice about power options, all great information. In particular, StarDrifter, I found quite a lot of unhappy campers on the net who've had their Celestron power tank fail for one reason or another.

So I'm going to go with an off-the-shelf 12V battery (probably a gel) and compatible charger. That way I can control exactly what I'm buying and learn how to use the gear correctly (plus if I do bugger something, it'll be easy to get a replacement).

I also fly large radio-controlled helis that run on pretty scarily big LIPO batteries (the kind that are serious enough to explode if you look at them sideways) and I know from that experience that recharging is the crucial part if you want to get good performance and lifetime out of your batteries.

I had a Meade 10" SCT many (i.e. 20) years ago, and that just ran on ordinary batteries, plus had an AC adapter supplied with it, so I was a bit caught by surprise by these modern mounts being without either. So all your information has been a great help, so thanks a lot!

[jeff.cotter]

Looks very neat. You've inspired me to do something similar. Neat and simple is pretty important when you're blundering around in the dark!

[impactcrater11]

I would avoid car batteries. they have exposed terminals so shock is a risk. they may be low voltage but require high amperage to do there work. just think of the 'strenght' it takes to turn over a car engine.
my celestron is powered with a transformer from dick smith. it has variable settings to 12 V and those pos to pos and pos to neg adapters. it is connected to an outdoor socket on my deck and i do not find cord wrap a problem. and it has in-built house electric safety features when you do something 'dumb'...

[Larryp]

The risk of accidently shorting out battery terminals is very remote, since they are so far apart. I have used battery power for 30 years and have never had it happen. And you will not get a shock if your hands touch the terminals.
Most people seem to prefer batteries because there is no danger of overloading the mount electronics-no power spikes, etc.:)

[raymo]

I heartily endorse everything Larryp said. Also, your transformer is useless if you take your scope to a remote site, and also you could easily get a simple box to put the battery in, if shorting worries you. The
battery sits happily tucked away under the tripod legs, so what are you
likely to short. If you want to be really paranoid you could even wrap
the battery in an old shirt or something. I've been using batteries even longer than Larryp, and have never had a problem, or heard of anyone else having one.
raymo

[impactcrater11]

it is wise to only use an energy generating devive for its chosen purpose
please note this wise web site
http://www.hse.gov.uk/pubns/indg139.pdf

[Larryp]

Most of the batteries we use are deep cycle sealed gel cells or AGM batteries-no leakage of any chemicals.
Modern chargers will not overcharge a battery-the charger switches to float mode once the battery is fully charged and you can leave it on add infinitum if you wish.