iEGrow via Amazon offers Prime members its iEGrow 2-Bay Smart Li-ion LCD Battery Charger for $16.99. Coupon code "AXIVQ7J3" drops it to $9.34. Plus, Prime members bag free shipping. That's $1 under our March mention, $10 off, and the lowest price we've seen. It features a voltage detector and recharges 3.7-volt lithium-ion batteries. Deal ends May 19.