Those are mostly used batteries and not very good at what they are supposed to do. majority are telecom batteries which are suitable for smaller loads for more sustained periods of time, not running houses completely on them.. besides there are no gaurantees how old and abused they are, and no returns.
a new smaller battery will be more suitable and reliable than these used worn out larger batteries.
Still, sometimes a person can be lucky and may find a good piece at decent price.. thats just luck though..
