I just received the latter one today, and put it into another P60 host, but with just 1x18650, because it’s a 4.2V drop-in.
Anyway, so tonight, I was comparing the two lights, and I was surprised that the light with the FastTech drop-in appeared brighter than the one from Lighthound, even though the light with the drop-in that I got from Lighthound had 2x18650 (i.e., 7.4V vs. 3.7V)! By brighter, I mean both white wall hunting and out my back door. The difference is pretty noticeable.
I guess that I don’t “get it”. Why is the one I got from FastTech so much brighter, even though that light has lower voltage?
Input voltage to the drop in means nothing… it is the current delivered to the LED that determines the output. The lighthound drop-in is acting as a buck converter and is set up to deliver less curent to the LED.
I guess that I’ve been trying to develop a sense of how to judge a drop-in.
So, is current a good way to do that? However, it seems like a lot of times, the specs don’t include that (e.g., the Lighthound one doesn’t indicate that).
Lumens? But everybody always says that advertised lumens are not accurate.
Measuring current is a great way to compare brightness, I would invest in a DMM if you don’t already have one. Remember when measuring current for an 8.4v driver with 2 cells in series you should double the current to get a relative comparison. i.e 2 cells in series at 1.5A is equivalent to 1 cell at 3A.
It’s not a problem measuring current if I already have a given drop-in, but really, what I’m trying to figure out is how to try to judge a drop-in, like when I’m trying to decide to buy it or not, or, if I’m trying to choose among several of them. Is the only way then to buy all of them and measure the current?