What is it?

LilLiPo is a small 8mm x 18mm board offering full LiPo battery management. It will charge a 3.7V (1S) LiPo battery, and offers many protection features to keep the battery healthy.

• Constant current / constant voltage charge management for 1S 3.7V LiPos. A version with a charge current of 100ma and 212ma are available.
• Under voltage protection. LiPo batteries can become damaged if drained too low. With this in place, no need to worry.
• Over charge and over voltage protection.
• Output short circuit protection prevents load shorts and over discharging.
• Input/charge voltage reverse polarity protection.
• Always-on protection with a low power drain of ~4µA.

Specs

• Input voltage for charging should be between 4.25V and 6.5V. Must be at least 30mV above the battery voltage to charge.
• Charges to 4.2V within 1%.
• Charge current set at 100mA. Trickle charges LiPos drained below 2.9V.
• Over discharge trips at 2.4V and restores at 3.0V.
• Short-circuit protection trips at 4A within 8 milliseconds, or at 20A in 70 microseconds.
• Over charge trips at 4.3V, e.g. if accidentally charged from output circuit.
• Adds only 40mΩ inline to the battery.
• Pretty li'l at 8mm x 18mm.

Why did you make it?

Often cheap LiPo batteries ship without any protection circuitry. I built this to have a combined simple LiPo battery management system, and to be as small as possible while still being easy to solder.