Sears offers the Craftsman C3 19.2-Volt Lithium-Ion Compact Battery & Charger Starter Kit, model no. 35710, for $58.79. Opt for in-store pickup to dodge the $6.95 shipping fee. That's a buck under our September mention, $41 below list, and the lowest price we've seen. It features a 30-minute charge time and is compatible with all C3 tools.
Of note, Shop Your Way Rewards members will earn a Sears credit with this purchase and may be eligible for additional credits and discounts.