Remote powering AP1100gto

[batema (Mark)]

Hello,

I am going remote for a period of time under very dark skies and am asking if someone could advise me on power for my set up.

I have an Astrophysics 1100 with SBIG 8300m and self guiding filter wheel. I will be running the guiding through the SBIG and a computer.

I know I need a deep cycle battery but wondering how I will run my laptop as well.

Any advice would be extremely grateful as I am leaving on Thursday morning.

Mark

[Nortilus (Josh)]

depending on the laptop you can actually get larger batteries for them extending the running time. You could also lower the brightness of the screen (should be one of the function buttons) this means it will draw less power. You can also go into your laptop bios and most laptops will let you run the CPU at a reduced speed conserving battery life even further. Charging it during the day however is something you may need to look into. Maybe solar 12v battery to 240v converter. Not really sure.

[AndrewJ]

Gday Mark
You can also use a std DC-DC converter to step the deep cycle battery voltage up to suit the lappie if longer use is required than the std batteries will give.
One thing i found with my lappie is they specify it must have a 19V DC supply, but this is so it can charge the internal battery as well.
If i run my lappie off 15V or less, the lappie still runs happily, but the internal battery charger is isolated, and hence it becomes much more efficient.

Andrew

[RobF (Rob)]

Gee Mark, it really takes a lot of battery juice for a rig like yours for even 2 nights. I have 35, 45 and 80AH batteries, and running 2 rigs (laptops and HEQ5 + EQ6, 2 cameras) can't quite get 2 nights.

Very rough figures, but in order of draw, you'd be looking at something like:

Dew heater: ?5AH?
Laptop: Very dependent on model, DVD drive etc - 0.5 - 2AH (some small footprint lappies use very little power)
Mount: 0.5-1AH tracking, 2AH slewing (wild guesses for AP off EQ6 values)
Camera, etc: 1AH

You definitely need a DC/DC convertor for lappie (and maybe mount AP uses higher voltage than 12V?).

2 big issues will be having sufficient amp hours for at least one night, and sufficient power and charging capability to be ready for next night.
Based on values above, that's around 8AH for say 10hrs - most deep cycle batteries shouldn't be taken below 30%, so that would require around a 120AH battery, unless you find a way to cut down on the dew heater.

At Leyburn if there's no-one with a genny, I found the local corner store was happy to let me leave the battery charging for a small fee.


Don't know if I'm more jealous of your beautiful mount, or of the thought you'll be under pristine skies! Probably both!

[Stickboy (Phil)]

Mark when I am camping I use a 80 litre Angel fridge LED tv and I run my laptop from the same battery using a 12v step up that any retailer like Harvey Norman and the like will sell you there are lots to choose. during the day I charge the battery with a solar cell. I started with a 80 watt cell but now use a fold out 3 panel 150 watt cell.

Phil

Edit - the internal battery charges fine with this setup