Close

Initial LED Selection

A project log for E-Bike Light

A project with very strict requirements: design and build a bike light that can be powered from the 52.6V battery on my E-Bike.

manselMansel 10/19/2019 at 05:590 Comments

When I set about this project the first thing I wanted to work out was what LED I was going to use, as this would drive the requirements of everything else in the project, driver, lens, heatsinking, etc. Due to personal preference I decided that I wanted a colour temperature of around 4000K and a CRI above 80. A collection of LEDs that I have come across are documented in the table below. All values in the table are the absolute maximum found within the manufacturer’s datasheet for a middle of the road bin (Expect for the Cree XHP70.2 in orange, more on this later). Please note I have updated this table through out the project and not all of these LEDs were on my radar at the start of the project. Link to Google Sheets Comparison Table

During my initial search I decided upon using the Cree XHP70.2 LED. I chose this LED since it was the brightest, but still somewhat sensible LED choice. Part of the reason I chose this LED is that I found a review of this LED showing that it could be overdriven to very extreme levels. The values from the review is the orange row in the table above. Link to review.  After I decided I was going to use the Cree XHP70.2 LED, I set about ordering it from Digi-key as well as a heatsink and a number of optics from Aliexpress. To power the LED for testing I was just going to use a bench power supply.

Discussions