Hello Karen, Thank you for your inquiry! Pertaining to your question: How do I charge this, I borrowed this from my local dive shop to test to see if I wanted to purchase but I don’t remember how he said to charge it? Your local shop should have loaned you a Quick Charger to charge the NiMH Battery Packs
http://www.scuba.com/scuba-gear-159/031270/Patco-Aqua-Heat-Dry-Suit-Heater.html If you have other questions, need help or would like to place an order, please contact one of our Instructors at SCUBA.com by calling 800-247-2822 <> 949-221-9300 or e-mail us at: info@scuba.com