Good information, stay far away from battery lead. I don't know where lead comes from now since our lead mine shut down. It is why it costs more now. Imported now.Just for your information. Lead from old car batteries is alloyed with Arsenic and other poisonous items to improve it's use as a battery. I recommend that you not go that route. There are large companies that refine battery lead. They heat the lead to a gaseous state and then run it through a column still. They separate the lead from all the additives. There is no way for the hobbyist to purify lead. People that work in those factories wear air supplied full coverage suits and still have to have monthly blood checks.
Watch the stick on WW's too, I sorted them out since everyone says they are pure but almost all were zinc.
You can remove almost all zinc if you keep lead at 600° only, do not flux and skim the zinc off the surface. It looks like oatmeal. You might remove some tin with it if you have a mix. When I do a batch of WW's I keep the temp at 600° also and any weight that will not melt gets removed.