hey, i have this power outage/emergency lamp mod in my mind for some time,
plan is to use this module wich have low battery protection, it will charge a few 18650 in parallel and will be on at all time, and once the power go down it will switch on the led(some xml), when power is back the led will tuern off and battery will be charged,
so far i can think of two obstacles wich i need help with,
1- how to make the led to outomaticly switch on while power go down, i could use a relay but im not sure how efficient it will be…
2- how to drive the led in the simplest / cheapest way possible, i dont realy need it to have mods and most driver with mods could swap mods if power go down and up for a sec, i could use a one mod drive like this but then i thought 3A is abit too strong and i will probly end up removeing few 7135s, so now im thinking to just get few 7135s and use them like the pic below, would this work or do i need some resistors/diods/capacitors?
thanks. 
