I have only one piece of advice regarding Wal-Mart batteries. (Well 2 but one is generic about ALL batteries)
First the Wal-Mart specific: When giving amp hour ratings Wal-Mart uses the "At one amp" rating method.. Thus a Group 24 battery can break 100 amp hours.
This battery is not higher in capacity than say an Interstate.. It is roughly 75 amp hours at the 20 hour rate, Same as all the other Group 24's They get the higher number by using a slower discharge rate.
This is not illegal, or non-standard, mostly because there is no standard.
The other "Generic"
Wal-Mart, I'm told, sells a "Trolling battery" this is not a Marine/Deep cycle (Which everybody sells) nor a starting battery, but a true deep cycle.. LOOK FOR IT if you are replacing house batteries.. I've not yet found it but .. I see they claim to have one.
Other than that they seem to be OK batteries, Average at worst. Trojan's are better, but not worth the higher cost.. Interstate may be better, same cost comment. I hae 2 of them in my mix.
Home is where I park it!