Field power?

Hi guys,
What is everyone using to run your laptop, SBIG camera, and mount at your remote sites?

Equipment:
ST8E camera
Dell Latitude D610 laptop
Losmandy G11 mount (non go-to)

I'm trying to figure out whether to purchase a 400w power inverter to run my laptop and ST8 off AC from the same 12V marine battery that runs the G11 or get dedicated DC cables for them (expensive!!). What combination will get the best battery life? I think my battery is rated at 95ah. The laptop AC adapter says 1.5a @ 110v and the AC adapter for the camera says 43w @ 115v, not sure what the mount needs. Some online power calculators seem to indicate only 3-4 hours of operation time, which seems awfully low.

Thanks,
Robert

Robert…

One way to find out what your AC powered equipment actually draws is to get a "Kill A Watt" meter by P# International. There are several, and Amazon carries them. I have the $34 version.

Your AC adaptor is rated higher than your laptop actually draws, so you should be able to get more than operating time. How much, I can't tell.

Fred

Hi Robert,
Inverters are hogs for power and run the battery down faster than using 12v adapters. You should get a Car Adapter for your laptop and use the 12v power plug for the Gemini and then get the 12v adapter for the SBig camera.
This is what I use and it works fine. I have a 135 amp hr battery now, but used a 115 amp hr until it gave out.
The number of hours it will run depends on the laptop as much as anything. They use a bit of power if they are a 17" monitor type.

I used to use two 6v golf cart batteries to give 12v approx. 225+ amp hr. I now use a Honda 2000u generator (clean sign-wave), 1/3 the weight and runs all night on a tank of gas(1.1 gallon). I can run 2 AP1200, 2 CCD, 2 laptops, dew-heaters and more with no problems. I can even fire-up a microwave for a midnight snack. I find it better then lifting and moving 2-80 lb batteries and worrying about acid spells and running out of power.

sam

Robert Watters said:

Hi guys,
What is everyone using to run your laptop, SBIG camera, and mount at your remote sites?

Equipment:
ST8E camera
Dell Latitude D610 laptop
Losmandy G11 mount (non go-to)

I'm trying to figure out whether to purchase a 400w power inverter to run my laptop and ST8 off AC from the same 12V marine battery that runs the G11 or get dedicated DC cables for them (expensive!!). What combination will get the best battery life? I think my battery is rated at 95ah. The laptop AC adapter says 1.5a @ 110v and the AC adapter for the camera says 43w @ 115v, not sure what the mount needs. Some online power calculators seem to indicate only 3-4 hours of operation time, which seems awfully low.

Thanks,
Robert

I use a deep cycle marine battery (aka trolling motor battery) and an inverter. I tried a DC - DC converter for the laptop, but it couldn't handle my guide camera, which is a DSI, which uses a lot of power off the USB bus. It will work intermittently with the ST2000...it worked OK till I upgraded the laptop memory (a big, honkin' 3.2 ghz Toshiba). I think my main problem is the PC, not the ST2000 and its Peltier. Eventually, I'll get smart and get a netbook. Anyhoo, with inverter and big battery, I can go as long as I want, though not all night.

The scope (either a NexStar 11 or an Atlas mount) runs off its own separate jumpstart battery.

Robert,
I use about 140 Amphours worth of battery. I am powering 2 mounts two cameras (one is a DSLR so not much power there)and two laptops. What I have done is to use 3ea 35 AH batteries and 2ea 17AH. I keep my G11 mount on a separate 17 AH. I use an inverter and a DC/DC converter (from Lenovo). As Floyd says, the DC/DC converter is more efficient, but mine does not isolate input/output.

I look for as much isolation as possible between mount, laptop and camera to minimize noise and ground loops. So I connect the size battery applicable to the load and interconnect components by only one ground (when opto isolators are not involved).