So there are tons of different sellers on internet selling these blue 10-280Ah LiFePO4 batteries. There are many sellers and manufacturers, but they all seem to sell same looking batteries. Price vary from seller to seller, from website to website, but all the batteries are pretty much the same. Is there some standard with these batteries or this is just one real manufacturer and others just resellers? Because I've seen prices in ranges from 70$/kWh to 500$/kWh.