Kobalt 24-V Batteries: 2Ah $20, 4Ah $39 + Free Shipping on $35+

Lowe's has Kobalt 24-V 4Ah Battery (KB 424-03) for $39 and Kobalt 24-V 2Ah Battery (KB 224-03) for $19.98. Shipping is free for Lowe's Rewards Members or choose store pickup where stock permits.