Li-Polymer Battery for HP iPAQ 3800 / 3900 series Compaq iPaq Battery Type: Li-Polymer Volts/AmpH: 3.7V 2200mAh Dimensions: 86 x 55 x 3.5mm This PDA replacement battery is designed for Compaq iPaq 3800, 3835, 3850, 3870, 3900 Part No. 263897-001