Q. With lights on during day time also battery does get drained off?Does this effect the battery life - Activa i?

I have Pulsar 150 (2017) In 2021 I Extend 2 led lights for better visibility at night time, So What i Experienced is My battery discharged very soon.. in 2 years I have to replace my battery and after the new battery in last 6 months I had to recharge the battery and also replace Magnet disc ( Magnet Assembly Cover The Coil Plate Which Helps In Giving External Amount Of Energy To the Other Electrical Items.). So this is my experience with adding additional light to a bike.. Note: if magnet disk goes fail then your bike will not start. so have to go urgently mechanic shop

Do you mean with Day Running Light (DRL) system in BS4 headlight is on everytime when vehicle is operating, so does this drain the battery? Answer is NO. LED bulbs are used which have very minimal power to affect the battery. Still if any issue arises then you can get it repaired/replaced within warranty.

During running on question of battery getting drained. With in warranty period you can claim for a new battery