A Great caving headlamp
Features
- The Apex has a 3-Watt LED spot beam and 4 ultra-bright 5mm LEDs with a broad beam for close-in use. It uses four AA cells and is rated waterproof/submersible to 1 meter (printed right on both cases!) It can use Alkaline or lithium 1.5V primary cells, or 1.2V NiMH rechargeable cells. It is available for $70 at Campmor, and as little $65 plus postage elsewhere.
- Physically, the lightweight headpiece has a deeply recessed lens for the 3-Watt LED; rubber-covered pushbuttons mounted on the bottom that will never turn ON accidentally; full tilting from horizontal to vertical position; and a large aluminum-finned heat sink with a protective cover.The pushbuttons can be operated with gloves on, after a little practice.
- The battery pack mounts on the rear of the headband, where it must be to avoid compass errors. The lamp does not interfere with compass readings. The case is rubber-covered to reduce damage from bumping into things, and for comfort when worn without a helmet. The case open with a single ¼-turn fastener with a positive feel. The required tool is built-into the headband, or a coin or blade can be used. The case is o-ring sealed. Both pieces remain connected to the headband when the pack is open, and the AA cells snap into the portion of the pack with the cable – no loose pieces or contacts here. The cable is robust, with strain reliefs and guide clips.
- Both cases have screws, making repairs possible.
- UPDATE
7/6/2012 The absolute best feature has
turned out to be the fact that they stand behind the
lamp with a 100% lifetime warranty!!! I have
just received my third lamp for just the cost of a
phone call to get an RMA number, plus 1-way postage
to return the old lamp. My second lamp had a
stripped screw in the headpiece (unknown to me) that
eventually let water in. I dried and repaired
it in the field, but it eventually flooded again
while climbing in a waterfall. The screws did not
appear to be too long.
| NOTE
ON
WATERPROOFNESS 3/29/07 A number of people
around the
world have reported problems with water leaking into
the
headpiece. The problem appears to be caused by
the 3 screws that
hold the headpiece together, which are too long for
the holes they are
screwed into, preventing proper "squeeze" on the
o-ring seal. The
cure is to remove the 3 screws and shorten them by
roughly 1mm.
The o-ring and sealing surfaces can be lubed before
re-assembly.
To prevent cracking the case, do not overtighten the
screws.
Cracks have been seen in headpieces that have never
been disassembled,
but so far none have caused leaks.
As a precaution, the cable should be sealed externally at both ends with urethane cement aka "Shoe Goo". The repaired lamp can be tested by submerging in shallow water for 30 minutes, WITH NO BATTERIES INSTALLED, then drying the outside and opening it to check for leakage. A lamp that already has water in the headpiece may exibit intermittent operation and shut itself off. The cure is to open it up, dry it completely until it works normally, then complete the repair described above. |
- The electronics have just the right combination of features to make the Apex a great caving light. The big spot LED has two settings, drawing roughly 3.5 Watts or 1 Watt from a fresh battery. The four small LEDs also have two settings, drawing about 1.3 Watts or 0.25 Watts. Note that the four LEDs cannot be ON at the same time as the big LED.
- The headpiece has a tiny LED that monitors battery voltage, changing from blinking green to yellow to red as the battery voltage drops. The monitor LED is activated when the lamp is first switched ON, and continues blinking for 24 hours after the lamp is switched off.
- The really good part is that the LED changes to yellow at precisely 4.0 Volts. When this occurs, the main light blinks twice (in whatever mode it is in) to alert the user of this fact. This is the ideal voltage to stop the discharge of four NiMH cells (1 Volt/cell). The Apex is one of the few current-regulated LED lights that can use NiMh cells without worrying about reverse charging damage.
- It gets even better! Below a threshold voltage (~4V in HI and lower in the LO power modes), the current regulation is disabled, allowing battery current (and light output) to gradually fall. This greatly extends the “end of life” of the battery. In all modes, the LEDs just go dark at 2.4 Volts, which really exhausts the cells.
Positive Comments
- The light seems to me to be better built than Petzl lamps.
- This light ideal for NiMH rechargable cells. It uses 4 cells rather than 3. Some chargers only work with an even number of cells! Both NiMH and Alkaline cells come in 4-packs.
- The light is small and light (and waterproof!) that a second one can be carried as a backup/spare.
- I highly recommend the Ray O Vac 1 hour smart charger, which charges 1 to 4 cells individually (not in series), giving each only what it needs. This charger is designed for a 12 Volt source (your car!), but also has a 120V wall-wart for home use. Faster chargers push the cells too much.
- I also recommend not purchasing the very highest capacity NiMH cells. The somewhat lower capacity ones (say 1800-1900 mA-hrs) seem more reliable to me, especially when doing fast charging.
- I normally use it in the LO spot beam mode, which actually uses somewhat less power than the 4 small LEDs in HI mode. It should run continuously for 9-10 hours in this ~1 Watt LO spot mode. The HI spot mode is great for spotting leads, but is a battery hog. The 4 LEDs in HI mode are ideal for small passages and light-colored passages because of the superior side-light. The 4-LEDs in LO mode are fine for taking survey data, reading, or emergency use where it should give a couple of days of continuous light.
- My Apex worked flawlessly for one month in Belize, including a lot of swimming. With underground times in the 8-10 hour range, I only had to switch NiMH cells once, when I forgot to recharge after the previous trip. I did manage the light output carefully, but we were either moving or surveying most of the time underground.
- The following chart shows the power drawn from the battery for all 4 modes as the voltage drops. The drop in power drain (and light output) below roughly 4 volts is clear. The reason for using the LO Spot mode for general caving is also clear!
Negative Comments
- The black o-ring seal on the battery case is not glued in place. When the new case is opened for the very first time, the o-ring may stick to both parts and can be broken or lost. I had no trouble except for the initial opening, and have not had to glue it in place.
- The 4 small LEDs are driven very hard in HI mode – I estimate 90 mA each, assuming 90% electronic efficiency. I wonder about their lifespan, although mine are still bright.
- I don’t like the blinking mode, but
it is
not encountered in normal operation. The
programming of the two
pushbuttons is excellent.
Additional comment: A 3-LED conversion module is available at Walmart for $5.00 that will turn a MiniMag in a fine long-lasting backup/emergency light that also uses AA cells.