Grassland,
To your replies to my initial post, it sounds like you have the skillset and tools to build a portable. Some time spent researching designs, wiring, fuses/breaker etc. and I have no doubt you could put together a unit to your specifications. You are certainly further along the curve than I was. I guess the last component to that would be if you think you would find the process enjoyable, find satisfaction in having done it yourself, and place value in having the ability to repair/modify. I hate changing out starters, or replacing vehicle springs, but do so begrudgingly. My 12v journey has been mostly fun and rewarding.
As to batteries in general, there are two extreme thoughts you find on this board. Buy them cheap, thrash them hard, replace frequently. Versus buy them expensive, threat them right, fuss over everything, and try and make them last. You'll have to find your comfort level on that continuum. Myself, I try and buy decent quality and pay attention to the details, as much as is needed not to have AH Anxiety while enjoying the great outdoors.
I would absolutely recommend NOT doing flooded for a portable. Maybe a tiny system, but as had been mentioned, the potential outgassing and the fact that you may be storing/using this indoors sure points to AGM, at least. My portable was built in a Pelican case, with two 35ah agm's, and with the rest of the stuff I have in the case is well over 70 pounds. I keep 4 17 watt GZ panels in my case, that add a bit to the weight. It is a pain to move around. Some folks have used hand trucks built into their boxes, but sooner or later you are going to have to lift the darn thing. The AGM's allow me to stand it up, lay it down, and generally not worry about how I have to store it.
Sounds like you need to figure out a way to test the draw of your current configuration. With my 70ah portable (35 useable ah's), I could run my fridge, all led lighting and occasional small device charging for a weekend with minimal to no solar. With a 100 watt panel, I could go much longer. I know the draw of pretty much any "thing" that touches any of my systems, input or output side.
While not as cold as your location, my winters in NM are pretty cold. Months below freezing at night and weeks below zero (F) at night mean that all batteries that can be moved get stored inside. My van has flooded starters and my mounted house bank are AGM. They sit out, but they are essentially getting trickled by my solar during daylight hours. Well, at least after I brush the snow off my panels. If you go lithium, methinks that you will need to move them indoors during cold weather, or invest in a way to charge them, when they are not in a cold state. And lithium batteries are not as solar friendly as flooded or AGM. That can be done, but you will need to do your homework as to how.
For the right user, those lithium packs sure would be sweet. Plug it into the wall to charge, store it in a temp controlled environment, grab it to go exploring. Or have the wife grab it.
Craig
www.suaoki.com
www.goalzero.com
