I believe that this is better
http://cgi.ebay.co.uk/Two-7-2V-4500mAh-NiMH-Battery-Packs-For-RC-Cars-Tamiya_W0QQitemZ260291820046QQihZ016QQcategoryZ340 61QQtcZphotoQQcmdZViewItemhttp://cgi.ebay.co.uk/Two-7-2V-4500m...ars-Tamiya_W0Q QitemZ260291820046QQihZ016QQcategoryZ34061QQtcZpho toQQcmdZViewItem
You get 2 for about the same price as the one you linked.