My power monitor on my battery indicates 0.3A at 12.22V, or 3.765 Watt difference when I don't power the display.

Heh. You should try running it from a phone!

[No. No, you shouldn't. You seem like a nice person and it would be a shame for you to go insane.]

I have found that for the initial setup, a laptop is really nice, especially the keyboard. But it's perfectly possible to run it from, say, an iPad without too much ensuing raving and gibbering. I often start out by connecting to my Pi with my laptop, configuring everything that I need to do much typing for, and then, as the laptop's battery ebbs, closing it and checking in via the iPad from time to time once things are running in automated fashion. If I had a Bluetooth keyboard for the iPad I could probably even do without the laptop, but since I have both devices, I just use them.

I started off using only a phone. It. Was. Infuriating. So much wasted time to accomplish simple tasks. But it's perfectly fine for monitoring and doing simple things. Tablet it perfectly workable, but onscreen keyboard leaves much to be desired when it covers half the screen. Bluetooth keyboard was a game changer, now I'm relying less on the tablet, and going to that display.
Laptop is a good all included solution, but it's a power hog and suffers in my climate. I rarely have access to AC power too.

I also started by using just a phone. Yes, it was doable but very frustrating.
Today I tried to simulate the "in the field' situation. All running on the RPI. VNC to RPI from a tablet. No keyboard/mouse - just the touch screen.
It was difficult but I managed to get everything running.
Did the polar alignment, mount alignment, slew to the target, set-up the auto-guiding.
Unfortunately, when I started to shoot the actual sequence, KStars crashed after the first frame (on FITS preview) .
Latest nightly build.
Never happened to me before but I didn't use it directly on RPI for more than two months (was working perfectly back than) - was using a Windows client.
So, I switched to the Windows client (the larger screen and the mouse!). There I also had some problems - also a recent nightly build - CCDs would become unresponsive (several times) and I would have to restart KStars.
In the end I got about 60 shots... Successful but troublesome session.
Tomorrow is supposed to be another clear night - I'll try again.

Have you guys trid EkosLive? It's free and meant for Tablets/Phones. It's a lot simpler of course, but it gots most tasks done. Only cavet now is it it require online connection. But we have an offline version in the works to be released soon.

EkosLive is great! But is of no use without internet connection as you mentioned.
Can't wait for the off-line version - thanks!

Got that monitor/display (different brand). It's actually pretty good especially after I got a thin/longer HDMI cable. Monitor/keyboard/mouse connected directly to RPI seems like a good "in the field" solution.
Also changing the default Stellarmate screen resolution of 1152x864 to 1920x1080 helped a lot.
Thanks for pointing me in the right direction!

IHOUJIN/All,
Just had a freaky experience involving that 10" RPI monitor (which I like very much).

Yesterday it was clear for the first time in many weeks. So I gave my setup a try. With this nice monitor, keyboard, mouse and a new portable table.
Everything worked fine!
Today. Same everything. But nothing worked. The mount forgot its wifi settings and I couldn't get them set. Stellarmate hotspot disappeared.
Spent a couple of hours troubleshooting.
Got it!
The only difference was - I put the monitor not on the table but attached it to the tripod leg (too close to wifi sources I suppose).
The monitor interferes with wifi and basically kills it if put too close to wifi sources. Moved the monitor further away - all is well!

That's peculiar!
You mentioned you found a different model, can you link to it for reference?
Just how close was the display to the Pi? I haven't noticed any WiFi issues myself.

This monitor - www.amazon.com/gp/product/B076GZVCP2
It was about 60 cm (2 feet) away from RPI. Moving it just a little further (maybe twice the distance) removed the interference.

Looks identical to mine. I can't say I've seen any interference, but mind you the Pi 's internal WiFi is pretty weak, so I use a more powerful external adapter.

I use the internal wifi and the monitor was actually closer - just one foot away.
Problem solved but good to know of potential problem