Let's see how much current can we put through the LED and still make the 1 year battery life goal.

From the last log we have around 31ms of MCU activity time and 1.5ms of LED-on time. We also have around 180mAh of battery capacity left for transmitting the data.

From the datasheet we get at most 2mA supply current in active mode using the internal 4.8MHz RC oscillator (divided by 4, all peripherals disabled). We'll try to calculate the maximum number of transmissions from a single battery depending on the LED drive current.

The formula is:

Where N_tr is the number of transmissions, Q_bat is the battery capacity, Q_tr is the capacity used by a single transmission, I_μ and t_μ are MCU current and time and I_D and t_D are LED current and time. We divide the calculated value by 365*24 = 8760 hours in a year to get the maximum number of transmissions in an hour.

And the calculated values:

We can safely aim for 500mA and 1 transmission per minute. Even with extra losses in the system we'll meet the 1 year battery life goal.