What battery should I use to power my setup

[mtodman (Matt)]

I need to purchase a battery to power my telescope setup for the upcoming SPSP. My setup includes the following:
-LX200GPS
-IMB Notebook PC
-Dew Heater
-Cameras
Total current draw will be around 6-8 Amps.
Can someone tell me what sort of battery I should purchase (SLA, AGM, ???). What capacity should I be looking at (Amp Hours) to last a full night (preferrably 2 nights)?
Finally, does anyone know a good supplier in teh Sydney area?

Cheers

Matt

[Omaroo (Chris Malikoff)]

Matt - why don't you plug in to the supplied power in the imaging area at SPSP - at least for the laptop?

You're otherwise going to need a largish 80-100AH or even 120AH deep cycle lead acid battery I think. I have an 80AH one and I get 2 nights - just. I don't draw 6 amps though... at that rate you won't go a night without draining the deep cycle below the recommended 40%-odd residual charge.

[mtodman (Matt)]

Thanks Chris,
I was not aware that there would be power available for imaging at the SPSP (this will be my first time there). If I go for a battery at the lower end of your recommendation, it sounds like I would be able to charge it during the day, or as you say best case run my setup from the onsite power.
Cheers
Matt

[Omaroo (Chris Malikoff)]

I'm not sure whether their friendship would stretch to charging your large battery Matt - they're on a solar system, not mains. A few 10amp chargers wouldn't take long to kill it. I'm using a pre-charged 80AH to run my scope and heaters for the Friday and Saturday evenings, and running the lappy off their mains supply.

[mtodman (Matt)]

Big battery it is then. I don't suppose you know of any good sellers in the Sydney area?

[lacad01 (Adam)]

For fear of being shot down, I'll ask anyway ...
What's the etiquette of taking a generator to a dark-sky meet? (assuming one can assure of "quiet" operation in a suitably sound-proofed box), not talking about continuous operation either but enough to provide some charging, or even running it in the daytime after a night's observing/imaging session when I guess the observing fields should be void of ppl (that last statement is also an assumption as I've never attended a SP or dark sky meet...)
http://www.campertrailers.org/soundproof_box.htm
cheers

[Starkler (Geoff)]

Originally Posted by mtodman

I need to purchase a battery to power my telescope setup for the upcoming SPSP. My setup includes the following:
-LX200GPS
-IMB Notebook PC
-Dew Heater
-Cameras
Total current draw will be around 6-8 Amps.
Can someone tell me what sort of battery I should purchase (SLA, AGM, ???). What capacity should I be looking at (Amp Hours) to last a full night (preferrably 2 nights)?
Finally, does anyone know a good supplier in teh Sydney area?

Cheers

Matt

50% discharge on an SLA will bring you down to 12v and you dont want to go lower.

Full night 8hrs? Two nights 16hrs.

16hrs x 8amp x2= 256AH battery

[mtodman (Matt)]

That poses the question "how do people image over 2 nights without ready access to mains power". I would assume that my setup is pretty typical for astro imaging. I would also assume that there are not too many 256 hour SLA batteries to be found at star parties.

I guess a generator may be a solution (either to power stuff at night or to rechange batteries during the day). I understand that some people do use them at the SPSP.

Matt

[Chippy (Nick)]

If I recall correctly there are generators near the meeting hall (near main observing field) where you can charge your batteries during the day. I think this is what most people do. So as long as you have enough charge for a full night, you can charge up each day.