EXHIBIT 10.13


Summary of Guaranty  Contract of Maximum Amount by and among Longgang  Division,
Shenzhen Development Bank,  Development and Construction (Group) Company Limited
by Shares of Changchun Economic & Technology  Development  District  ("Changchun
Co"), Jilin Provincial  Huaruan  Technology  Company Limited by Shares ("Huaruan
Company"),  Xiangqian  Li,  Yanlong  Zou,  Fenghua Li, Jimin Li,  Jiajun  Huang,
Baicheng Zhou, Jinghui Wang, Yongbin Han, Shuquan Zhang, Xinrong Yang, Yunfei Li
and Weiqiang Zhang dated as of April 1, 2004.

         Changchun  Co,  Huaruan  Company and 12  shareholders  of Shenzhen  BAK
Battery Co.,  Ltd.  (Xiangqian  Li,  Yanlong Zou,  Fenghua Li, Jimin Li,  Jiajun
Huang,  Baicheng Zhou, Jinghui Wang, Yongbing Han, Shuquan Zhang,  Xinrong Yang,
Yunfei Li, Weiqiang Zhang) (collectively,  the "Shareholders") signed a guaranty
on April 1, 2004 in relation to the Comprehensive  Credit  Facilities  Agreement
(the "Agreement") as summarized in Exhibit 10.12. In the guaranty, Changchun Co,
Huaruan  Company  and the  Shareholders  undertake  to assume  joint and several
liabilities  for the  obligations  of Shenzhen BAK Battery Co.,  Ltd.  under the
Agreement,  subject to the maximum security amounts of RMB 100,000,000 Yuan, RMB
50,000,000 Yuan and RMB 150,000,000 Yuan for each shareholder respectively.  The
guaranty has a term of April 1, 2004 to April 1, 2007.