So basically Michael it all depends what you want to do now and in the near future. Take note of your mounts power consumption 2A at max draw, laptops about 3 - 4A max draw, DEW heaters about 3 - 5A MAx Draw.
You wont draw 2A from your NEQ6 unless you are slewing at top speed so really draw is at most times less than 1A when tracking a object at rate 3. Write off 40% of the batterys claimed capacity as not usuable ie. 12AH becomes a 8AH. Then you get a true expectation of the available power in Amps per hour. Go atleast a 12AH AGM Battery for just pure observational use of your telescope.
Good luck
