Battery Pack

Zuts · #1 09-04-2007, 06:21 PM

I just got a 24 amp hour SLA battery pack (the type with the jumper leads) with a cigarette lighter atachment from Super Cheap Auto's. I plan to use it to power a Celestron Nexstar 11. Does anyone think i would damage the scope and would be beter of getting a power pack from Bintel or should it be OK.

If it's not suitable i can return it.

Thanks Paul

xstream (John) · #2 09-04-2007, 06:24 PM

It will be fine, Paul.

We've used one on an LX90 for about 2.5 years and never had any trouble at all.

Zuts · #3 09-04-2007, 06:37 PM

Quote:

Originally Posted by xstream

It will be fine, Paul.

We've used one on an LX90 for about 2.5 years and never had any trouble at all.

Thanks Xstream. I'm still a bit worried as i have heard a few stories about celestrons being fried not using the celestron power pack, but maybe this is a dealer trying to sell me something overpriced that i can get somewhere else.

Solanum · #4 09-04-2007, 07:51 PM

An 12v SLA battery is a 12v SLA battery, doesn't matter where it comes from or what the capacity is, it's stillt eh same voltage range. Put a fuse in the positive line from the battery though. You'll have to find out the max current that the Celestron draws and get a fuse a bit bigger than that.

Popeye (Bert) · #5 09-04-2007, 08:42 PM

I've used a small 12v 7ah battery to fire up my LX90 for the last 4 years and it works fine. I have another battery (18ah) for the corrector heater but the little 7ah works wonders for hours.
BUT! Be very careful with polarity! I was unaware that I had crossed polarity on the scope battery after charging it once and it fried the LX90! Bintel supplied the part and instructions on how to fit it and with the help of a mate I was able to do this. The alternative was to send it to Bintel from NW Tasmania at my cost and a repair cost of $100.
I don't know if Celestron have the same wiring circuit but be very careful just in case! A battery of that size seems like a bit of overkill to me and I love the portability of the little 7ah battery with carry case. I also had a cigarette lighter connection from the spade connectors to the battery.
Polarity doesn't matter on the larger one for the heater.
Good luck!
Cheers!
Popeye

Zuts · #6 09-04-2007, 10:03 PM

Hi Popeye

The unit i have has a cigarette plug. I plan on plugging a 12 v standard lead which ends in a cigarette plug adaptor into the powerpack. I will not be touching any leads and with only one connector to the pack am a bit confused about how i might reverse the polarity.

I definately dont wish to fry my scope, did you use it this way or directly of the terminals somehow.

Thanks Paul

Rigel003 (Graeme) · #7 10-04-2007, 12:14 PM

I use a 17 amp hour starter battery with my 11" Nexstar and have never had any problems. The telescope itself draws very little but when you plug in dew heaters it's a different story. A 24 ah battery should be plenty though.

Zuts · #8 10-04-2007, 12:32 PM

Quote:

Originally Posted by Rigel003

I use a 17 amp hour starter battery with my 11" Nexstar and have never had any problems. The telescope itself draws very little but when you plug in dew heaters it's a different story. A 24 ah battery should be plenty though.

Thanks for everyone that replied, i will try the pack i have on my scope,when it arrives...

Thanks for that, its good to get a reply from someone with a similar scope. By the way, i have a dew shield, did you try this on your scope and then go to the heater because it wasnt effecive?

Thanks Paul

Rigel003 (Graeme) · #9 10-04-2007, 04:49 PM

Quote:

Originally Posted by Zuts

By the way, i have a dew shield, did you try this on your scope and then go to the heater because it wasnt effecive?l

Yes. There will be occasions when you can manage with just the dew shield and many more when you need both. I usually set the heater controller to its absolute minimum setting throughout dewy nights and it always suffices.

Popeye (Bert) · #10 10-04-2007, 05:39 PM

Paul, I am not too sure if the Celestron has this 'gizmo' that burnt out because I reversed polarity. I found out later that it was as well that it was this 'gizmo' that went first or I could have fried the lot. (Help someone from Bintel!)
I have two leads coming off the battery. Both have a spade fitting to connect to the battery terminals. They end in a female cigarette lighter piece. As I understand it - and you would need to check this - the red terminal (positive?) goes to the centre connection of the cigarette lighter fitting. I have to take the spade fittings off the battery to put the terminals of the charger on. The terminals are marked red and black. So the red lead should go on the red terminal and so on. I was not careful and when I disconnected the charger I put the cigarette lighter part back on with the red to black and vice versa! The next night that I went out - actually to show off how it worked! - nothing happened. A call to Bintel told me the sad truth. You will need to find out more about cross polarising for your scope, possibly from another Celestron user.
As previously mentioned I use two batteries: one for the scope (7ah) and one for the dew heater (18ah) because I have a heater control on the dew heater and when it cuts in and out it causes spikes in the current and this can play up with the tracking a little bit.
Hope that I have not confused or frightened you more!

Cheers!
Popeye
PS Will be away for a couple of days now.

Zuts · #11 10-04-2007, 06:37 PM

Quote:

Originally Posted by Popeye

Paul, I am not too sure if the Celestron has this 'gizmo' that burnt out because I reversed polarity. I found out later that it was as well that it was this 'gizmo' that went first or I could have fried the lot. (Help someone from Bintel!)
I have two leads coming off the battery. Both have a spade fitting to connect to the battery terminals. They end in a female cigarette lighter piece. As I understand it - and you would need to check this - the red terminal (positive?) goes to the centre connection of the cigarette lighter fitting. I have to take the spade fittings off the battery to put the terminals of the charger on. The terminals are marked red and black. So the red lead should go on the red terminal and so on. I was not careful and when I disconnected the charger I put the cigarette lighter part back on with the red to black and vice versa! The next night that I went out - actually to show off how it worked! - nothing happened. A call to Bintel told me the sad truth. You will need to find out more about cross polarising for your scope, possibly from another Celestron user.
As previously mentioned I use two batteries: one for the scope (7ah) and one for the dew heater (18ah) because I have a heater control on the dew heater and when it cuts in and out it causes spikes in the current and this can play up with the tracking a little bit.
Hope that I have not confused or frightened you more!

Cheers!
Popeye
PS Will be away for a couple of days now.

Thanks Popeye,

My unit has a built in female cigarette plug, so there is no messing around with wires. You just plug things into it that have the male connector and away you go. So hopefully i wont have your problem.

Cheers
Paul

Popeye (Bert) · #12 10-04-2007, 08:22 PM

Good luck, mate!

(I was just about to log-off and turn the computer off when I checked to see if you had got the message.)
Cheers!
Popeye

33South (Chris) · #13 10-04-2007, 08:25 PM

Quote:

Originally Posted by Rigel003

Yes. There will be occasions when you can manage with just the dew shield and many more when you need both. I usually set the heater controller to its absolute minimum setting throughout dewy nights and it always suffices.

In between there's also the trusty 12v hair drier, which I now have.

I was having trouble getting hold of one - tip from the guys at Linden a couple of months ago, try any boating supplies shop

not being a naval person it had never crossed my mind.

Zuts · #14 10-04-2007, 08:39 PM

Quote:

Originally Posted by 33South

In between there's also the trusty 12v hair drier, which I now have.

I was having trouble getting hold of one - tip from the guys at Linden a couple of months ago, try any boating supplies shop

not being a naval person it had never crossed my mind.

Interesting idea mate, but i would be too scared of cracking the corrector plate.

Popeye (Bert) · #15 12-04-2007, 05:36 PM

It doesn't take very long to clear the corrector plate with a 12v hair dryer. It makes sense to keep it a reasonable distance from the plate, of course. But its only an emergency thing to cover the time it takes to either get a dew shield on or get the dew heater stoked-up. (How do you heat dew?

) But I wouldn't use it too often as my experience with the hair dryer is that it draws a lot of power from the battery pack! Better to have it hooked up to the car cigarette lighter and then not for too long!

Cheers!
Popeye

Popeye (Bert) · #16 13-04-2007, 08:05 AM

PS to my last. I have a 6 metre extension cord to reach to the car cigarette lighter. Meade used to be generous and supply one with the old LX50s. I kept it when I sold it for the LX90.
It should not be difficult to get one made ensuring that the polarity is correct!
Cheers!
Popeye.

erick (Eric) · #17 13-04-2007, 06:26 PM

Quote:

Originally Posted by Popeye

....But I wouldn't use it too often as my experience with the hair dryer is that it draws a lot of power from the battery pack! Better to have it hooked up to the car cigarette lighter and then not for too long!

....

I just measured my 12V hairdryer as pulling 12A! Sure warms up the 10A fuse I have in line from my battery!