I have a battery pack with two rechargable batteries in ....each battery measuring 150 cm long , 100 cm high and 100 cm wide .... the only figures on them i recognise are .... 6-DZM-12 .... please could anyone decipher this to simlpeton terms as i need a couple of new ones and dont know what to get ( via ebay ) .... MANY THANKS X ( they're really heavy ... )