https://alexnld.com/product/crtc42qa-4ch-type-c-usb-500ma-1-cell-lithium-battery-charger-module-board-for-3-7v-lipo-polymer-li-ion-18650-503035-603443-battery/?hilite="2PCS BestFire 18650 Battery 3400mAh 40A 3.7V USB Rechargeable Li-ion Battery With Protection Board"