New to solar, setting up my very basic new equipement:
What if i plan to use by phone as a hotspot for 24/7 (another words i'd like to have it run without me all the time)The battery is the easy way. It's your solar time machine. It can be collecting energy while you and your phone are off doing whatever, and then let you charge your phone when convenient, regardless of what the sun is doing at that moment.
It's also only two extra wires.
A 50-70Ah usable (depending on who is telling you) Grp 27 Deep Cycle at walmartha is <$70 and that’s enough to actually do something. A Giandel 300W true sine wave is ~$60 snd will run cordless drill battery chargers and a soldering iron. Or the stupid leftover laptop I have that says something stupid and nonsensical like “21V” on it’s charger so my 12V can’t direct connect to it….hotspot the ONLY thing you'll be running? If you ever even might run something else, like the inverter referenced in your first post, you'll definitely need a battery.
The DC to DC converter listed does not require a battery. I used that for four days camping, and will start again once the weather cools.I looked at the description of the one you linked to above, but I can’t say definitively if this one requires a battery or not.
The issue I had with phones was related to, but not exactly like surging. What happened was that the phone would stop charging when clouds came over & the voltage dropped, but then not start-up again when the clouds moved on. There were also times when the phone wouldn't charge at all during overcast periods. That's why I went with the Voltaic rig. Their batteries are optimized to charge even while discharging allowing them to be buffer between the panel & device. Many other USB battery banks don't allow for charging & discharging at the same time.The DC to DC converter listed does not require a battery. I used that for four days camping, and will start again once the weather cools.
Once you start dealing with no batteries, I wonder how the phone deals with surging throughout the day. I put that together with a 12 - 24 VDC USB charger, which may take the panel straight, but I put a DC to DC voltage converter to hold the voltage steady. That way if the DC to DC converter failed, the USB still regulates the power from the panel.
A 10 watt panel like linked could charge it, but with using the phone 24/7 as a wi-if router, I’m not sure if it would charge it enough. I find my phone uses 1 amp (12 watts) when charging, and after charged charged drops to .2 amps - ,3 amps if I’m using it. I don’t know how that would do throughout the night. The 100 watt panel you have would provide charging power throughout all but the cloudiest days.
It’s just figuring out how much energy you need to last through the worst cloudy stretch of days for the year or the shortest winter days.