Walmart offers the DieHard 75/12/2 Amp Fully Automatic Battery Charger
, model no. DH-75A, for $34.98
. Pad your order over $35
to bag free shipping. (Otherwise, opt for in-store pickup to dodge the $4.97 shipping charge.) Excluding padding, that's the lowest total price we could find for a similar battery charger elsewhere by $37. It features emergency engine start, 12-amp fast charge mode, and 2-amp trickle charge mode.