Resistor Question for 3.4V LEDs

[ooty99]

Hi

I am have made a string blade with 100 BLUE LEDs that are 3.4V. I plan on buying a 3.7V battery and power bank. But I have a question for the resistor...

Ive seen videos where 3.7V batteries reach 4.2V when fully charged. This would probably not be good for the lights if I am resisting only a 3.7V when it is infact 4.2V. Should I resist as if the battery is 4.2V or 3.7V?

Also, since I have x100 20mAh LEDs, this is drawing 2000mAh. When I plug this into a resistor calculator online, it says that I only need a 1ohm 4watt resitor, is this correct? I dont want to go off and buy a bunch of stuff and turn out being wrong.

Thank you!

[grumblehound]

Hi

I am have made a string blade with 100 BLUE LEDs that are 3.4V. I plan on buying a 3.7V battery and power bank. But I have a question for the resistor...

Ive seen videos where 3.7V batteries reach 4.2V when fully charged. This would probably not be good for the lights if I am resisting only a 3.7V when it is infact 4.2V. Should I resist as if the battery is 4.2V or 3.7V?

Also, since I have x100 20mAh LEDs, this is drawing 2000mAh. When I plug this into a resistor calculator online, it says that I only need a 1ohm 4watt resitor, is this correct? I dont want to go off and buy a bunch of stuff and turn out being wrong.

Thank you!

my last string blade had 105 green leds (same voltage as blue) was to be 110 but when I tested my links of 20 found a blue one in the link and by the time I had removed it I was down to 105 (sealed bag from supplier go figure)
I work on setting the resistor for 4.1 volts you get 4.2 maximum on a multimeter very quickly drops to about 4.1/4.05v underload
1ohm 4watt is about right I use 5 watt just for extra protection as I find they stay cooler in a confined space the same 1ohm 4 watt also works well with 4.5v if you need to run it off 3AA batteries .....................hope this helps

[ooty99]

Thank You bro so so much. Have a nice day!