I use the Motorola charger below and it gives just about 2 charges. I bought it elsewhere. It's thin and has a built in cable so very compact/portable. Charges at 2.4 too. Under $30. works for me.

Motorola Power Pack Slim 5100 (In Retail Box) Black Portable Battery (DRDUNIPWR7) - ... https://www.amazon.com/dp/B00QDWZ9N2/ref=cm_sw_r_sms_c_api_gL8Jxb7DC9NER