Power sources at dark sites

[Varangian]

Hi all,

I am considering enternal power sources to run my motor drive on the EQ4. Considering I will occasionally be going bush to dark sites I am interested to know how some of you run your motor drives/laptops etc. when in the field.

I am considering two easy, cheap options. Plug AC straight into a battery pack jump starter (not sure how long these last though and whether it will get me through a full night) or look at DC input to my cigarette lighter in my car (although I am loathe to suck the car battery).

Does anyone have any other thoughts? :shrug:

[stringscope]

Hi John,

I use batteries for powering dew heaters at dark sites not a powered mount. I have 54AH and 25AH deep cycle batteries, the larger for scope heaters and the smaller for heated eyepiece case. I would be cautious using your car battery, might end up trying to guide the RACV into a remote dark paddock at 3AM.

Cheers,

[Allan_L]

I have a 30 amp hour deep cycle battery.
I can plug the mount drive and dew heaters into it (DC - 12volts - cigarette plug types).
My laptop I have to plug into an inverter (because although it transforms AC into DC - it is higher than 12 Volts).
Being sensitive, it needs to be a sine wave inverter.
The inverter plugs into the same battery.
The battery is a Blue Apple Thumper, made especially for deep cycle use.
It cost around $300.

The cheaper jump start batteries never used to last the night. Even a 17 amp hour battery was no match for a dew heater running four heater straps. Let alone the inverter.

Don't use the car (cigarette lighter) battery.
Being stuck with no battery to start your car at 2am at a remote site is no fun. (And does not impress NRMA call out people). I've done it twice. :help: I won't make that mistake again.

[mikerr]

Hi John,

Another suggestion here....

http://www.iceinspace.com.au/forum/showthread.php?t=76643

Michael.

[stephenb]

I hear you Allan :lol: Been there....

John I'm like Allen, I use a 26Ah Sealed Lead acid battery for a my Dob (with fan), laptop and 3 dew heaters.

Cheers,
Stephen

[Varangian]

Thanks all,

I knew there wasn't going to be a cheap option, but my wife tried to convince me otherwise :lol:

I may have to wait until my bday in 8 weeks to get a set up, esp after I just spent $240 in eps

[Varangian]

Hmmm maybe there is after all! Thanks Michael certainly worth looking into:thumbsup:

[inline_online]

I'm going to try this one as i'm getting sick of running extension cables over the back yard...
http://www.jaycar.com.au/productView.asp?ID=MB3594
Hopefully it works. It was recommended by a fellow astronomer.

[Varangian]

Hi Michael, do you have any idea how long you could run a 6v motor drive with intermittent use of a hair dryer from a standard 12.6v car battery?

Also is there any issues (power surges etc.) with connecting up a 6v motor drive to a 12.6 volt car battery via the alligator clips/cigarette socket scenario?

Thanks in advance.

[byronpaul]

In the field, I use concurrent configurations like the following .... all with deep cycle batteries:

Visual CGEM1100 - 1 x 30AH for mount + 1 x 80AH for Dew Heaters + accessories

Imaging HEQ5Pro ED80 - 1 x 26AH for mount + 1 x 80AH for Dew Heaters, Cameras, Laptop, etc.

I usually top up batteries each day with 240v charger, but I have run these set-ups for multiple sessions without going flat.

On a bad night, dew heaters draw a lot more power than the mounts so it pays to have a good one with multiple on~off controls.

[Allan_L]

I don't think it is possible (or at least not easy) to run a 6 volt motor from a 12 volt battery.

Unless you know how to string resisters to the line.

I would not risk it.

[Varangian]

Oh okay.

So it is not as simple as acquiring a car battery, clipping alligator clips onto the terminals with a DC socket on the end and then plugging in my 6v motor drive?

Electrical infant here:help:

[Davros]

I think that would let the smoke out of the wires. Deep cycle batteries are getting very cheap. Another idea is to obtain a pair of 6volt golf cart batteries and wire them together to give 12v plus up around 200+ amp hours of usage which should be more than enough grunt to run astro gear.

[MrB]

smoke

Edit: beaten by Mick :)

[Allan_L]

Sorry, but every motorised mount I have owned has been 12 volt.
So for me, it always has been just that easy.

I have no experience with 6 volt drives.

Additionally, all my inverters are 12 volts.
And my Dew Heater controller is 12 volts.

So this question is new to me.

Perhaps you could get a motorcycle battery?
Some of these are 6 volt I think.
But your other gear is likely to be 12 volts (in my experience).

Sorry for the bad news!
(Are you sure your mount is only 6 volts?)

[Varangian]

Okay thanks Allan,

I am not entirely sure if the drive is 6v, I took it to jaycar and they told me it looks like a 6v so they gave me a 6v power supply (but that doesn't mean it's not a 12v:confused2:), the 6v works okay but if it can run on 12v that will streamline my power supply at my dark site because as you stated my accessories are all 12v.

I received the drive as a gift and it works fine the only problem was it didn't come with a power cord. It is an EQ4 dual axis (see attached although this one may be single axis but you get the idea of what I'm trying to run). After much kefuffle I managed to get it installed and running, this is the last issue I have (determining correct power supply that is).

:thanx:

[Allan_L]

I did a search, and I found this in IIS Archives.
And it clearly says 6 volt DC power.
So it could well be the same.

I think the best bet is going to be to get a 6 volt battery pack (Jaycar?) for the drive.
Then you can still use the old car battery for dew heaters and to power the inverter for you Laptop (etc).

Unless someone else has a better idea?

[Varangian]

Okay that's my set up so it looks like it's 6v for me which means I need to run it external to my 12v accessories. The only difference is mine doesn't say 6V on the casing!
Thanks for your assistance Allan, I really appreciate it.

[MattT]

John if it has 4 D size in it it's 6 volts. I'm not sure but I think jaycar sell a 6 volt from 12 volt converter, I have a 6V drive on my EQ5 and am thinking of running it off a 12V battery, but the D cells run for a long time so it might not be worth the trouble.
Matt

[Varangian]

Okay thanks Matt, I'm thinking I'll go for a 6v battery and run it externally rather than going with a conversion. How are you running your 6v drive when you are away from a primary power supply?

[Chris.B]

I have the same drive and 4D cell power pack. I found a pdf and said 20hrs to a set of batteries. A Dolphin battery is also 6v and will last a little longer.

To get longer and rechargable get a 6v sealed lead acid battery from the likes of Jaycar. I have a bike headlight running the same battery. You can use a 6-7.5v plug pack to recharge it.

Hope that helps.

[Varangian]

Sure does, thanks Chris. I rang Jaycar before your post and they can set me up with a rechargable 6v battery including all connections to my drive for less than $40. I'm just going to have to live with carting a 12v and 6v battery around, but's that's not too much of a problem provided I am observing relatively close to my car.

Thanks all for your guidance.

[Varangian]

Just for the record I went to Jaycar and bought an inverter with a capacity of 500w (constant running) and a power surge of 1000w. The inverter has alligator clips that connect straight to a neat little 12v car battery with handles. I have an extension board running from the inverter with my motor drive (under 100w) and laptop and hair dryer (one of those Chinese foldable poratble ones @ 400w) all plugged in. I had it all up and running for a few hours last night and it all went all a okay!

This set up elimates a need to purchase a 6v and 12v battery for separate devices. All up cost was under $200 (just).
thanks all for your advice I ended up going with a couple of suggestions and rolled them up into one, without your advice a way forward would have been a lot more labour intensive.

[mswhin63]

Careful about using yur car battery off site just in case you drain too much power. I think most people including myself would prefer a separate battery, even another car battery will be my next purchase for off site stuff.

[Varangian]

I am using an external 12v car battery that I recharge at home. It will have days of life for what I need it for:thumbsup:

[Irish stargazer]

http://www.waeco.com.au/products5.asp?id=259&catId=77&subCatId=78&subCatId2=127

I have seen these used before to run a servocat, heaters and Argo navis on a big dob.

[MrB]

A hair dryer?

[Varangian]

Yeah I know I like to look my best whilst observing:P

Seriously, I've got to get around to purchasing dew heaters but a quick blast of the hair dryer will give me an additional 15 minutes before fogging up... What can I say my wife already thinks this is the biggest money pit.

[jjjnettie]

You can buy 12vt hair dryers from camping stores.

[Astro_Bot]

Truly? That begs the question: Who would choose to "rough it" camping and decide that they still need a hairdryer?! :screwy:

[jjjnettie]

Astronomers!!!

https://www.whitworths.com.au/main_listitems.asp?cat=123&Cat1Descr=Electrical%2FLighting&Cat2=696&Cat2Descr=Miscellaneous+12+Volt+App liances&Cat3=534&Cat3Descr=Hair+Dryers

[Astro_Bot]

That is actually quite a useful link.

I always like to look my best when observing! :P

[jjjnettie]

There's always the 12vt Superstore at Caboolture too. :)
Because sometimes you just have to browse in person.

http://www.solarpanelxpress.com.au/

[Varangian]

Hey that's my material!

I got the same hair dryer from China for $3.99 free post.

I needed a small foldable hair dryer up to a certain wattage because my inverter has a limit of 500 constant watts. I didn't want to overload it. A 3 second blast from one of these babies will give me clear eps/mirrors for 15 mins in really bad conditions.

[DavidTrap]

If you're handy with a soldering iron:

I bought a 5/6V 3amp BEC from eBay - it's intended to be used to power the receiver and servos of a model aircraft.

LINK (http://www.ebay.com.au/itm/Hobbywing-5V-6V-3A-Switch-Mode-Ultimate-BEC-UBEC-/261007973766?pt=AU_Electronics_Vint age_Electronics&hash=item3cc5499d86#ht_1032wt_922)

It will convert anywhere between 5.5-23V down to 5 or 6V (user selectable).

They are $4.50 shipped.

I'm using one for the RA drive on my EQ3. They could also be useful for powering USB hubs in the field - they usually require 5V.

DT

[Moon]

John
Another option to consider is to join the ASV. We have 240V power and piers on the observing field at our dark site. Makes life very easy.
http://asv.org.au/lmdss.php
James

[Varangian]

Thanks Moon, I have joined. Cheers.

[Chris.B]

ASV's LMDSS is a great dark sky location.
Hoping to get there this weekend if clear. The 240v is a real bonus.
You can use a 6v plug pack and not worry about batteries running low.
Nice to now run the LX200 on mains and not a dirty great SLA battery.