Sony Ericsson BST-37 K750 W800i W600i W600 battery.
The Sony BST-37 battery fits a number of phones including the K750, W800i W600i and W600 supplied at low prices.

Codenamed Clara the K750I is a candy bar styled phone that has buttons that can be used by any finger, it cam available in four colours including Black and came with the central Joystick..

A 2 mega pixel camera in landscape and a 176 x 220 pixel TFT-LCD screen with support for MP3.

This battery pack will fit other phones in the Sony Ericsson stable including the:
Sony Ericsson K750, D750, D750i, K750i, W800i, K600, K750c, W800c, W8, S600i, Z520, Z520i, W600, J220a. J220c, J220i, J230c, J230i, K310a, K310c, K310i, K510a, K510c, K510i, K600i, K608i, K610im, K758c, V600i, W300c, W300i, W700c, W700i 710c, W710i, W810, W810c, W810i, W850i, Z520c, Z525a, Z525i, Z530c, Z530i, Z550c, Z550i, Z710c, Z710i, W810, Z300a, W600i, W550i, W800, Z520a.

This rechargeable replacement battery Pack has Lithium Ion cells and a energy storage capacity of 650-milliamps at 3.7v.

The battery type Li-ion or Lithium Ion
The voltage of the packs is 3.7v
Capacity of pack is 650mAh.