who uses car batteries for power?

[troypiggo]

If you can't plug into the wall, say you're shooting at a remote site, and you use a car battery (not the one in your car so you can't get home :) ), how long a life do you get out of it?

I'd be running a laptop and HEQ5PRO Skyscan mount off it.

Do you recharge them? How? Do you swap it with your car one and let the car do the recharging?

(I warned you guys once this gear turned up I'd bombard you with questions :) )

[kevinf]

http://www.thinkgeek.com/gadgets/travelpower/962e/
http://www.wagan.com/htmls/powersupp.html

[troypiggo]

Thanks for the links. I'll look into those.

[Nighthound]

Troy, go with a deep cycle marine battery. Marine batteries are up to the task of being drained and recharged repeatedly. I have three, two that I use and one as a back up in case I (or my friend) need one at our dark sites. Too much work, expense and travel to let power failure shut me down.

I use one battery to power the mount only. The mount is plugged into a voltage regulator. The regulator is plugged onto a power inverter(750 watt) and the inverter has clamps that are connected to the battery terminals. IMO nothing else should be powered from he mount source, especially without a voltage regulator in line. Dew heaters for instance cycle, which means they are demanding power at various levels while keeping the dew/frost off your scope throughout the night. This fluctuation in current could effect the way a mount connected to the same battery performs. Since we work so hard for pin point accuracy, I don't like the possibility of a potential problem with tracking precision due to power fluctuation, which is part of why I picked up the voltage regulator. The regulator insures the battery power being supplied to the mount is consistent.

I use a second marine battery and a larger power inverter(1000 watt) for my laptop

My lightweight power units are two jump start batteries. One I use for the dew heater, the other to power my guide CCD camera(Atik 16 IC). I don't recommend the jump start units since they have a fairly short life. I got lucky and have one that's almost 2 years old but I don't expect much more life out of it. I'll likely switch to all marine battery power once these two go.

Picked up a Black and Decker battery charger and recharge to full before a night out. One of my marine batteries is going on 3 years old and another 2 years. The other is a few months old just in case one of the others dies on me.

[Adrena1in]

Good information here guys, that's great. I've not ventured to any dark sites as yes, but I would considering getting me some of these deep cycle marine batteries, I must admit.

(Though being "Green" minded I'm now wondering how much power I could get by using a bicycle-powered generator. Be a good way to keep warm during an imaging session! ;) )

[troypiggo]

Excellent info guys. Thanks so much for the hints.

[PM01]

Optima battery. Yellow top. Deep cycle.

I also use a special charger for the optima. Works great at our observatory.

[kaitanium]

i got myself a celestron powertank 12v (not the larger one)

http://www.ehobbies.com/csn18774.html?utm_source=csn18774&utm_medium=shopping%2Bengine&utm_campaign=froogle

it was cheap so i went for it. people say it can power your scope for 30hrs but i guess it fits my purpose cuz i only power my scope and nothing else.

is this a bad battery? no one here mentioned it haha. at that price you cant go wrong.

[Nighthound]

It'll work but it's not a great value when you consider its life. Charging and recharging these small units takes its toll. Now if you don't get out often then obviously it'll last longer. During a good year of weather I may get out maybe 12-14 nights. That's not a ton of recharging but enough to wear down the small jumper units and Power Tanks. Many people set up at home so they may be out much more than myself. But even when they are not used they will need a recharge from sitting idle so charging is inevitable.

A deep cycle>inverter>power supply>mount configuration may be more initially but will last a long time. The battery will eventually need replacing but not for years if properly cared for and charged. My biggest attraction to this set up was the regulator to help avoid fluctuation in power to the mount. One less thing that could cause issues in tracking precision.

[kaitanium]

ah yes. i wonder if theres a chance at replacing the internal battery only....like sending it in for service.

(sorry to hijack the thread)

but how much does one of those deep cycle setups cost (if i am only to power my cpc800)?

[PM01]

A yellow top Optima battery typically runs about 200 dollars. You can get these at summitracing.com - just stay away from smaller shops like Car Boutique or any of the honda/acura shops as they tend to mark it up significantly. (For them it was priced at 375.00)

The batteries will take MUCH more torturous environments and are worth the money. I've had a car starting orange top (also optima) battery last for over 7 years. And that's constant usage for a high mileage vehicle. Expect the same amount of time, or longer, for the yellow top battery if properly maintained. 10 years is not unreasonable.

You DO need a special charger that will be capable of handling gel and AGM (advanced glass mat) batteries. The standard Lead acid recharger will cause the acid to boil and possibly catch fire. This has happened to one of the corvette owners that I know. The charger itself is about a hundred dollars and can be bought at better automotive parts stores. I use the one from "West Marine". Great stuff. Digitally controlled.

[kaitanium]

wow sounds expensive!

[Nighthound]

Certainly PM's suggestion is of very high quality and if you do the math will be well worth it in the long run. 7 years is a good long battery life.

My choices are far less expensive and realistically should last over 3 years, especially if you use them and recharge them properly. I use the WalMart Deep Cycle Marine batteries(wet, not gel), I believe they run around $60. I run a couple of these each night out from sun down to day's first light and I have never even come close to running out of power. If I were to run out at 1 or 2 in the am after all that effort I'd be really upset.

What will you use to power your dew heater? Won't that be an issue or do you travel to a desert location?

[kaitanium]

oh i dont doubt his suggestions at all. i just want something simple to get me started. getting a car/marine battery seems like ill need to get a ton of accesssories with it too jacking up my costs.

i dont even have a dew heater or a shield yet so....seems like an unending list of stuff i need to buy. i guess i wont worry about that yet until i use the scope to take shots of deep space stuff.

[kaitanium]

ok im reading up on lead acid batteries (the thing thats in this celestron power pack) and it looks like its pretty high maintenece.

so what is needed+cost to use what you use nighthoud? ok so $60 battery, what is needed to charge it and such?

[Nighthound]

This is the battery charger I have. Got mine at WalMart:
http://www.blackanddecker.com/productguide/product-details.aspx?productid=15579&toolview=1#details

Power inverter. You can get these at large hardware and automotive stores too, but here's what it looks like:
http://www.amazon.com/VECTOR-750-Watt-Power-Inverter-VEC043/dp/B00009W3ZE

Power Supply. This allows you to plug in a cigarette plug power cord, I'm assuming your mount use one for its power(?) This unit plugs into the above power inverter. The inverter has positive and negative battery clamps that connect to the marine battery:
http://www.radioshack.com/product/index.jsp?productId=2103959&tab=features

Again it's... Battery > Inverter > Power Supply > Mount

[dpastern]

Can this be stickied by the mods please? Thanks guys.

Dave

[kaitanium]

just subscribe to it dpastern. im sure youll be able to find it again?

man that battery setup will be expensive. i think ill just my celestron one for now

[dpastern]

Yes, I have already subscribed to this thread, but it would be nice to be stickied, since it's an important topic in relation to running a Telescope.

Dave