At Amazon, get this Myvision 5-Gallon USB Rechargeable Water Bottle Pump Dispenser for $9.99. It's the best price we could find by $8.
A full charge is rated for 30 to 40 days, or roughly 4 to 6 five-gallon bottles. It fits 3-gallon to 5-gallon bottles and runs off a single switch.
Shipping is free for Prime members. Buy Now at Amazon
Features Fits 3-gallon to 5-gallon water bottles Built-in 1200mAh rechargeable battery via USB Pumps 1.5L of water in 60 seconds, then stops automatically Food-grade silicone hose, stainless steel, and BPA-free ABS plastic Measures 2.9" x 2.9" x 5.1" and weighs 8.8 oz.
