Hercules Deals - Charger, Battery, Tool

I was excited to see a deal for buying a 20V 8 Ah battery and getting a "free" tool; however, I just discovered the battery does not come with a charger and those are relatively expensive.

What's the best deal you've seen when it comes to getting a charger, battery, and tool from Harbor Freight?

Also, are there any generic chargers that exist which can charge all these different proprietary batteries?