Solarforce L2i

Today Grant and Mom and got flashlights. These are not just any flashlights, but take a lot of great features from a number of different sources. The flashlight is a Solarforce L2i. People absolutely rave about how great a light the Solarforce L2i is, and I will explain more about them later, but one nice thing is that it is a P60 host meaning it takes a standard reflector and bulb combination that is easy to switch out if you want to upgrade the flashlight. And unlike most P60 hosts, this one uses standard AAA batteries. So Mom and Grant also got some of the best AAA rechargeable batteries available: Duracell precharged with white tops that are made in Japan. These batteries are thought to the be the same thing as Eneloop batteries which are the best. What makes them great is that, unlike normal rechargeable batteries, these don’t lose their charge very quickly sitting around waiting to be used. While a typical battery might lose 50% of its charge in a couple of months, these batteries will only lost 15% of their charge in a year. So the flashlight will be ready to go whenever it is needed. But because the flashlight uses 3 batteries and most battery chargers only charge batteries in pairs, they also got a Sony Cycle Energy charger that charges the batteries individually. I have been very impressed with this simple and compact charger that does everything right. There are very few chargers out there that will properly charge batteries by using an acceptable current, cutting off when the battery is full, rejecting bad batteries, while charging batteries individually and without a trickle charge.

Back to the Solarforce. People really like this light because it is a convenient size and is very well made, milled from aluminum and made watertight with o-rings at the lens and all joints. This light can also stand on its end, so if the power goes off, it can be left on a table pointing at the ceiling and light up the whole room. It has been customized by carefully grinding down the stock pointy bezel that most people don’t like and the head is now smooth so it won’t tear pockets. I have also replaced the glass lens with one that has an anti-reflective coating that lets 99% of the light out instead of maybe 90% for regular glass.

The L2i doesn’t necessarily come with a P60 bulb and reflector, so I built a special one using a hard-to-find neutral white LED. Most LED’s come in cool white which is a little bluish, but these LED’s are more of a neutral color like an incandescent light. This is preferred by flashlight enthusiasts because it makes things look more natural than with a bluish light. The LED is a Cree XP-G model with a R4 brightness bin. That’s one of my favorite LED’s because it gives a nice balance between light output and how far the light will shine. Soldered with care to the brass pill inside is a circuit board that provides just the right current for the XP-G LED to perform at its peak. This is a new circuit board that only recently became available and has been modified by me to run with 3 modes: Low, Medium, and High. The Low is very nice for indoor use or close up, Medium is good if you want the light to run for a couple of hours, and High is very bright when you need all the light you can get, but will run through a set of batteries in about 30 minutes.

Because the LED produces a lot of heat when running on High, it is important to get rid of the heat into the body of the flashlight. However the P60 module doesn’t have that great contact with the light (this is a problem with all P60 lights, not just the Solarforce). Therefore I have cut out aluminum strips from a soda can to fill in the gap around the reflector and provide a better path for the heat. Unfortunately I didn’t get everything I needed on time from China, so I will end up replacing the aluminum strips with copper ones that should do an even better job of transferring heat than the aluminum strips.