It shouldn’t take longer than 3.5 hours from a fully depleted battery. Normally I would expect it to take about 1.5 - 3 hours in total. NOTE: Please make sure you only use the charging adaptor that is provided with the Tactacam product. If you choose not to you may cause overcharging that may damage the product. This is due to the output required from the charger of 5v - 1A.