I wouldn't call any of the 3 "ultra capacity". They all have something like a 35 ah 3s 11.1 volt battery pack inside. Even the "jackery unit" that says its a 140,000 mah (140 ah?), its too small to fit that many batteries inside it, it states 500 wh, which is about 40ah maybe. Hard to say with these units.
The smallest lithium I have is a 3s 11.1 volt 33 ah battery pack. Even though it's small, it is usable for my limited needs. I use it to run my swampcooler and lights and also an inverter to power my netbook. It easily does that till around 11 pm. The next day it requires about 16 amps to top it off. The 11.1 volts is no problem to run my inverters. I been using it as a house battery for the past 3 weeks, and it does the job very well.
The only problem with these battery packs is the long charge times, even with the wall socket it takes 6 + hours. They have to slow charge them for safety reasons, since it relies on the built-in BMS to do the balancing and the BMS don't balance well at high charge rates.
One thing about lithiums they are quite capable to be quickly charged with the right methods. On mine (that I built) I bought a balance charger (14 amps max output) and I can charge it at that rate. As long as it is in balance it will charge quickly at that rate, If its out of balance it will take longer, at the end of the charge it will reduce the amps to balance the battery. I always check on it while its charging and even when its almost full, the charger is still pumping in maximum amps.
From my own experience you can take them down all the way until the BMS cuts off the power, and do it all the time without damaging the battery. You also don't need to fully charge them. They are real "deep cycle" and "maintenance free". As long as you charge them correctly and don't hammer nails into them, they can be as safe as lead acid. The ones that catch on fire most likely went out of balance, over heated, melted the wires, which shorted out, causing sparks which then catch something on fire.
My kinetik 102 ah agm, didnt survive me taking it below 11 volts 3 or 4 times. And with solar I could never give it the high amps it wanted. Thats what made me switch to the lithiums. I still have the kinitek connected to the solar panel and use it to run my balance charger to charge the lithiums, thats all its good for. Without solar it don't hold a charge long.
This is what the inside of one of those battery packs looks like, they use the li-ion 18650 cells connected in 3 rows.
