Use this charge MCP73831-5ACI/MC charge controller from Microchip Technology to control the environment of your batteries. With an output that has a voltage of 4.5 V, this is power management at its best. Its output produces a current of 15 to 500 mA. This device runs on Li-Ion|Li-Pol. This battery gauge has an operating temperature range of -40 °C to 85 °C. This device has a minimum operating supply voltage of 3.75 V and a maximum of 6 V.