Review on 🔌 Etekcity Quick-Fill Rechargeable Air Pump for Inflatables - Electric Inflator and Deflator for Air Mattresses, Pool Floats, Boats, Rafts, Toys - Includes 3 Nozzles, 100-240V AC & 12V DC Adapter - Black by Lacueva Tranquillity

The manual recommends an initial charge of 5 hours with the AC adapter and 3 hours with the DC adapter. Unfortunately, you can overcharge your battery if you're not careful. There is no built-in system to cut off charging when the battery has reached full capacity. I wrote to the company and they suggested only charging from the AC adapter for 2-3 hours after the first charge. Here's the problem: it's impossible to determine how much power is left in the device. You may think that it takes 3 hours to fully charge, even though it only takes 1 hour to fully charge. So you overcharge it, which can drain the battery. As long as you are careful and let the device run until it runs out of power, there will be no problems. But estimating how much is left is a problem.