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Small, Light, Rechargeable Pack for NexStar?

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#51 Midnight Dan

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Posted 05 August 2014 - 08:18 AM

Mike:

 

The discharge rate is not really important because any of the packs have a much higher discharge rate than needed for the scopes.  But yes, I use the 12v 5000mah C sized pack.  The 10AH pack would be nice but is larger and would be hard to fit on the base.

 

Note, I use the 5AH unit to power BOTH my scope and dew heaters and I get 4-5 hours of use.  Of course, I use a DewBuster dew heater controller, which is very efficient on power use.

 

-Dan



#52 Sarkikos

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Posted 05 August 2014 - 09:21 AM

Yes, I would avoid the 10ah pack if it might not provide enough clearance between OTA and mount when pointed at zenith.

 

I use an Agena Astro Dew-Not controller.  If you can run both the scope and dew heaters for 4-5 hours, the 5ah pack should be plenty for anything I want to do for grab-n-go viewing at home.

 

I think I'll order the #5010F-3 5ah pack, Anderson Powerpole connector and the NIMH 5-10 cell charger today from MaxxPacks.

 

Mike



#53 Sarkikos

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Posted 05 August 2014 - 09:46 AM

I just ordered the power pack and charger.  I'll give a report when I try them out. 

 

Thanks everyone for all the help!

 

:grin:

Mike



#54 Arctic_Eddie

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Posted 05 August 2014 - 10:26 AM

That's the one. The discharge rate just means that it will supply that level of current to the load without damaging the cells. Your mount will draw less than 1A so you should see no heating of the battery. At a typical draw of 0.5A, you should get nearly 10 hours of use before recharge.



#55 Sarkikos

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Posted 05 August 2014 - 10:48 AM

10 hours of use before recharge... That would be at least three observing sessions at home, about two at my dark site ...  or maybe only one night if I fall asleep in the car!

 

Mike


Edited by Sarkikos, 05 August 2014 - 04:32 PM.


#56 Arctic_Eddie

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Posted 05 August 2014 - 02:20 PM

The flat pack can be mounted on top of the battery cover if clearance at zenith is not a problem or taped/velcroed to the inside of the vertical arm. The charger uses a low current so it will take several hours to charge. However, it has an indicator light so you'll know when the charge is complete. On the Anderson connectors, be sure the red and black wire colors match up when plugging two leads together. You might also look for the cable to connect the pack to the mount. It would have an Anderson on one end and a 5.5mm x 2.1mm barrel connector on the other.

 



#57 Sarkikos

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Posted 05 August 2014 - 04:19 PM

You mean I need another connector? If I had known that, I would have looked for one at MaxxPacks before I finished the order. Though I just now did a site search through Google and didn't find them at MaxxPacks.

 

Mike


Edited by Sarkikos, 05 August 2014 - 04:27 PM.


#58 Arctic_Eddie

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Posted 05 August 2014 - 05:46 PM

I also did a search and did not find the right combination. They had an Anderson pigtail( connector on one end and wire on the other) but I did not find a 5.5mm x 2.1mm with center positive tip. If you had those two items then you could connect the two red wires and two black wires with wire nuts. I'll look further tonight.



#59 Sarkikos

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Posted 05 August 2014 - 06:08 PM

This looks like what I need: 2.1mm DC Power Cord to Cable Anderson Connector http://www.ebay.com/...=p2054897.l4275

 

Such a simple thing. You'd think I'd be able to find one in a hobby or electrical supply store.

 

Mike



#60 Arctic_Eddie

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Posted 05 August 2014 - 06:18 PM

Here's the adapter you need. The description does not say the red plug is connected to the barrel's inner conductor. You should confirm this by email with the seller.

 

http://www.powerwerx...apter.html#desc



#61 Arctic_Eddie

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Posted 05 August 2014 - 06:24 PM

The eBay item will work. Since it's designed for amateur radio use, it's likely center positive.



#62 Midnight Dan

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Posted 05 August 2014 - 07:08 PM

In addition to the scope-connetor tip polarity (as Eddie Points out) you will need to be very careful with the Powerpole connectors!  Normally, they are used by people who assemble them themselves and make sure that the polarity is correct. But you can assemble them one of two ways.

 

Powerwerx uses the "kinda" standard way of assembling them.  That is, with the tongues of the connectors down, viewed from the front, the black connector is on the right.  See the image here:

http://www.powerwerx...apter.html#desc

 

The MaxxPacks site shows the connector assembled the opposite way if you scroll down on this page:

http://www.maxxpacks...p?cPath=250_253

 

If you aim the two at each other, you will ONLY be able to connect them together in the WRONG way.  You will see that black mates with red and visa versa.  If this is the case with the cable you receive from MaxxPacks, you can fix it relatively easily.  First, if there is a metal pin in the hole in the top of the connector, you'll need to push that out with a jeweler's screwdriver or other small object.  Then, you can slide one half of the connector forward and the other to the rear.  You'll see that each half has tiny plastic dovetails molded into the surface.  You can slide the two together again in the correct orientation using these dovetails.  If you removed the metal pin, put it back in.

 

 

-Dan



#63 Sarkikos

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Posted 06 August 2014 - 06:01 AM

Maybe I should buy the Anderson Powerpole - 2.1 DC cord from MaxxPacks to make sure that they connect the same way. And make sure that the red plug is connected to the barrel's inner conductor.  One thing I don't like about the MaxxPack connector is that it's 3 ft long. I don't like having all that extra cord I don't need, but I also don't like having to splice cords.

 

I think I'll go to some local hobby stores and such to see what they have.

 

Mike


Edited by Sarkikos, 06 August 2014 - 06:02 AM.


#64 Arctic_Eddie

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Posted 06 August 2014 - 06:10 AM

Good catch Dan, I didn't look at the photos to see that error. The eBay item looks correct and is short. That may be the better deal. Since it's intended for amateur radio use, the polarity should be center positive.



#65 Sarkikos

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Posted 06 August 2014 - 06:31 AM

But does the eBay item look like the black and red connectors are in the same orientation as the Anderson connectors I'm getting from MaxxPacks? Looks like the opposite to me. I'd rather not have to take the eBay item apart and reassemble to make it match the MaxxPacks.  Otherwise, it seems great. As you said, it's short and polarity will be center positive.

 

Mike


Edited by Sarkikos, 06 August 2014 - 06:33 AM.


#66 Arctic_Eddie

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Posted 06 August 2014 - 07:36 AM

The orientation of the eBay item is the same at the Powerwerx, which is correct. The part that is a little puzzling is that the metal contacts should be visible in the second photo. The metal tabs should be near the front of the connector body with the lip turned down. Perhaps they just didn't push them in until they clicked into position or this was just assembled far enough for the photo. As Dan said, the two halves can be swapped in about 15 secs. They stick together quite well and really don't need the roll pin.

 

PS

You could get the Powerwerx cable and just leave the excess length tied up as shown in their photo.


Edited by Arctic_Eddie, 06 August 2014 - 07:39 AM.


#67 Midnight Dan

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Posted 06 August 2014 - 08:27 AM

Hmmm, yes that eBay one does look odd in that you can't see the connectors in it.  Not sure what's going on there.  

 

I'd get the one from Powerwerx like Eddie suggests.  If there's too much cable, just wrap it up with a zip tie or strip of velcro.

 

By the way, here's an article I wrote a while back on Anderson PowerPoles.  You might find some useful info here:

http://www.cloudynig...conectors-r2337

 

-Dan



#68 Sarkikos

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Posted 06 August 2014 - 09:31 AM

Thanks for the link to your very informative article!

 

Mike



#69 Sarkikos

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Posted 06 August 2014 - 10:53 AM

There is a hobby store in my town that specializes in RC model planes. I'll see if they can supply me with the connector I need. Maybe I'll stop by the store today.

 

Mike


Edited by Sarkikos, 06 August 2014 - 10:54 AM.


#70 Sarkikos

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Posted 06 August 2014 - 06:12 PM

I dropped by the hobby store. Nope, no Anderson connectors on the premises. They had a sign on the front door which read, "Due to low sales, we will now be closing at 6PM." Sad commentary on today's economy, and maybe also on hobby stores. I felt like I should buy something, but really there was nothing I wanted or needed. I've lived in this town for 26 years, and that was the first time I'd ever set foot in the store.

 

Mike



#71 Midnight Dan

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Posted 06 August 2014 - 08:19 PM

Yeah, it's a shame.  But times change.  Everything can be had on the internet now, for less.

-Dan



#72 Midnight Dan

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Posted 06 August 2014 - 08:21 PM

Sooooo ... Mike.  Why is your location listed as Nyctophobia - severe fear of the dark?  :hmm:

 

-Dan



#73 Sarkikos

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Posted 06 August 2014 - 09:59 PM

Yes, a typical suburban town full of nyctophobes.  It is really pathetic how many adults are afraid of the night and the dark.  I used to call it "Scotophobia," but I changed the name because I didn't want to offend any Scots. 

 

:grin:

Mike


Edited by Sarkikos, 06 August 2014 - 10:00 PM.


#74 Midnight Dan

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Posted 07 August 2014 - 06:14 AM

Ah, makes sense.  I was thinking Nytophobia would be a bad place for an astronomer to live! :lol:

 

-Dan



#75 Sarkikos

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Posted 07 August 2014 - 09:33 AM

Often we don't have much choice. :mad:

 

:grin:

Mike


Edited by Sarkikos, 07 August 2014 - 09:34 AM.







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