LiFePo is often a better spend probably for most systems but some circumstances still will be best served with lead acid.
As a fan of lead acid, I can't argue with statements like that at all.
Are you running your batteries in really hot or below freezing conditions? Buy lead.
Are you on a really tight budget? Buy lead.
Are you only using your batteries a couple times a year? Buy lead.
Do you use your batteries every day? Get Lith.
Do you have limited physical space? Buy lith.
Do you want this system to run for decades without having to mess with it much? Buy Lith.
Back to the OP and original topic, it comes down to the age old "It Depends".
As for the capacities, the really simple way to think of a solar setup is water and buckets:
The
Ah or KwH rating of the battery is how big a bucket you've got. A 200Ah bucket holds twice as much water as a 100Ah bucket.
The
wattage from your solar panels is how fast you can refill the bucket.
The
load or
draw on the system is how big the hole in the bottom of the bucket is.
The
capacity of the system in
runtime is how long the bucket will hold water if it's got a hole and you can't refill it. The smaller the hole or bigger the bucket, the longer you can have your sprinklers running.
An
inverter is a pump that takes the water from the bucket and converts it to a high pressure spray.
The
rating of the inverter is how much water it could hose you down with at a time. A 1Kw inverter can feed a garden hose, a 5Kw is more like a fire hose.
Does that help at all?