Can I run my telescope from my car?

[laservet]

I usually carry a 12v battery to power my telescope mount and dew prevention heaters when out at night observing. I had back surgery in December, now cannot lift the battery. Can I just use the 12v sockets in the car?

 

[Zoomit]

That's a good question. The 12V battery isn't as large as a ICE car battery and of course you don't want to run it down. I think the car has to stay "on" for it to use the high voltage battery to recharge the 12V battery. I'm not sure how to ensure the HVB is recharging the 12V.

One other thing to consider is that when the car is "on", the screen may also be lit and bright. On that note, I have a dark sheet that I throw over the roof of my car to keep interior lights from possibly disturbing others at star parties.

Consider buying a Li-ion battery, that would be lighter than a lead-acid battery, to power the scope. I wouldn't risk killing your 12V battery, unless you have high confidence that it's being charged by the HVB.

 

[iustin]

From the current user manual, page 128:

Camp Mode allows you to power electronics through the USB ports and 12V outlet in addition to maintaining the cabin temperature. The touchscreen remains on so
you can play music, browse the internet, play games in the arcade, or watch shows in Tesla Theater. You can also control media and climate settings from a paired
phone. Camp Mode is ideal for remaining inside your vehicle, such as camping or staying with a child.

Modulo what @Zoomit said about the screen is "bright", it looks like camp mode is what you want here, since it keeps suppling accessories through the "main" battery.

I don't have a Y, but from what I've seen on the internet, camp mode for a night shouldn't consume too much (for example, this reddit thread has number for M3, which should be comparable - only 30 miles over night).

 

[jcanoe]

You should be ok powering your telescope mount and heaters as long as the combined 12V accessory amperage is less than 12A continuous, 16A peak. The Model Y has two 12V accessory outlets. One in in the center console underneath the armrest, console tray. The second accessory outlet is in the rear, driver's side, close to the seat release buttons. You would have to leave the ModelY in Camp Mode so the 12V system stays active. You can't run down the 12V battery, the Model Y will charge the 12V as needed as long as the Model Y's battery pack has some charge. You did not say how many hours you typically observe or photograph but Camp Mode should only use a few % of the battery charge per hour as long as the climate control is turned off.

 

[laservet]

Thanks, all. The draw is way less than 12A continuous 16A peak, and it's only for 4 to 12 hours. I can either throw a cover over the display or put a red filter screen over it, turn the brightness down low either way.

This helps a lot, my days of carrying 50 pounds are over.

 

[jcanoe]

Thanks, all. The draw is way less than 12A continuous 16A peak, and it's only for 4 to 12 hours. I can either throw a cover over the display or put a red filter screen over it, turn the brightness down low either way.

This helps a lot, my days of carrying 50 pounds are over.

For extra credit - figure out a way for the telescope's image to be displayed on the Tesla screen. Use the Tesla's steering wheel scroll wheels to adjust the focus and alignment of the telescope. Show your work.