The Ryobi One+ 18-Volt Lithium Ion 2.0Ah Battery and Charger Kit is just $43 right now, 52% off its $89 list price. This kit ...

So not only will the MH-CD42 charge your lithium-ion cells when given a nominal USB input voltage (4.5 – 5 VDC), it will also provide essential protections for the battery. That means looking ...