Scantronic 9600?

Hello all,hope you can help me with my 9600?,
The old girl has been going strong all these years until last night,never let us down but she lacked the attention she deserved by way of servicing.

Typically the alarm sounded at around 4am this morning and woke the whole family,i entered my code at the keypad which stopped the bells but now the keypad is alternating,top line= reset required,bottom line= battery failure.

Neglect I know.

Now this afternoon I opened the panel and found two 2x 6v 7ah batteries in there which iam having problems finding replacements.I have tried the Internet but all retailers seem to have 12v not six.

Only six volt I can find are for what look like replacement batteries for external sounder's,can anyone kindly tell me where I can purchase these batteries from?.

Much obliged.