This is a sample review of one of my bike lights, posting it to see if there is any interest in such reviews Sorry for any possible errors or weird spelling - english is not my native language. Feel free to ask any questions about this light, I'll try to answer all of them.
Shadow BL20 was bought here:
https://www.fasttech.com/p/1359100
This light is sold only in 2 stores and nobody seems to have it, so there is no information about it anywhere. Lets fix this
«Shadow BL20» all pictures are available here, you can also view high-res originals (click on any picture, bottom-right corner will list all resolutions, use google translate if needed)
PACKAGING / CONTENTS
Simple cardboard box, with Shadow sticker on the top and small sticker with model name on the side:
Box arrived slighly damaged, but light and contents were ok. Here is what you get in the box, protected by 2 layers of foam:
Light, battery, charger, extension cable, manual. You can find pictures of manual in the main album, if somebody can translate it - please post translation in this thread.
DESIGN
First of all - its basically a Shadow TC750X flashlight with bike mount, you can read detailed review about it here:
SHADOW TC750X (2 x XM-L U2 | 2 x 18650) Review
But there are some modifications and differences which I'll describe later.
Light dimensions: 65x60x35mm (without mount), weight: 170g. Its a bit larger and heavier than most other 2 XML lights, but still small enough to be used on bike. Here is a comparison pic with my other 2 XML lights:
It also has a larger reflectors than other lights:
This should give it a bit more throw.
Light has nice CNC-machined body with grey/titanium finish, looks very good and different from the usual black lights. Bezels are made from stainless steel, body is made from aluminium, its big and heavy enough to handle 2 high-current leds.
It also has a very interesting custom mount - its a 2 piece design, made from sturdy plastic:
Its attached to the light with 1 hex screw with a rubber spacer to keep it in place. You can also rotate light head from left to right if needed.
To attach it to handlebar you simple unlock the mount, place it over the bar and lock it by moving the bottom part up. It has ratchet-style locking mechanism, with a row of teeths on upper side and a pawl on bottom - which work very well and very fast. There are also 2 rubber inserts glued to mount which will grip the bar and prevent light from sliding up/down, here is how it looks when attached:
Overall - very nice mount design, I really like it. Can be attached/removed in a few seconds to handlebars from 32 to 22mm.
BATTERY
This light uses custom connectors for battery, with 2 small pins side-by-side in the connector, rubber o-ring for water seal and screw-on cap to prevent disconnection. This connector looks very simular to Niteye connectors and while completely non-standart it works very well, here is it compared to Niteye B20:
Light and battery have 2 very short cables attached to them - this is intentional and made for mounting light and battery close to each other (for elight on the handlbars and battery on the stem). There is also a long extension cable if you need to mount the battery further from light.
Battery is a simple 2S2P pack made from 18650 cells, most chinese lights use such batteries:
Battery capacity is marked as 4400mAh, actual capacity measured on my Imax B6 charger at 0.7A current was about 4700mAh, here is a discharge graph:
Battery protection activated at 4.5V, which is good for this light since it depends on low discharge for battery indication (explained later in the review). Battery can also handle 3.5A charge and is probably made from good cells unlike most other chinese bike lights batteries.
But battery is not protected from water! Be sure to give it additional protection by wrapping in plastic bag/rubber balloon or something, this is very importand - or it could be damaged in the rain.
UI
Simple UI, controlled by the button on top of the light. From turned off state one press of button wil turn on the light, modes are switched with single click between 3 levels (Low, Middle, High). Double click will turn on strobe mode, single click in strobe mode will return light to previous constant-light mode. To turn off the light hold down the button for a few seconds. There is no mode memory so light is always turned on in low mode.
TEARDOWN
Lets try to open it up and see how its made :thumbsup:
Starting from the front its possible to unscrew the bezels, then remove the glass and o-ring under it, then remove the reflector:
Interesting thing - reflector has orange peel coating, is made from aluminium and actually has threads on it, so you have to unscrew it from the body:
Led inside the light:
This light uses XM-L2 leds which are about 10-20% brighter compared to the XM-L. Leds are mounted on 20mm stars, stars are glues with thermal glue/thermal silicone to the body. Mounting looks very nice and clean, with just the right amount of glue and will give the perfect thermal transfer to outer case. Unfortunately this also means that its almost impossible to replace the leds, this thermal glue is VERY hard to remove (I tried to do it on other lights and usually its impossible to remove glued stars).
We won't get inside from the front, so lets assemble the reflector and try from the back:
Back cover was very hard to unscrew, threads are covered with same thermal silicone. From the view inside you can really see that its just a flashlight modified for bike use - 2 wires are soldered to battery connectors. Battery cable is also fixed with a zip-tie, that should protect it from pulling from the case.
Next step - unscrew the retainer ring, again very hard to do with threads covered in glue. This gives us access to the driver:
And unfortunately thats where I'll have to stop the teardown and I won't be able to measure current on the leds
This light is clearly not made to be taken apart, everything is glued together, wires are too short to unsolder from driver. I could cut them and remove the driver but then it'll be very hard to assemble it...and since I paid for this light myself I don't want to destroy it.
Some notes about the driver - its a usual buck-type driver, converts high voltage from battery to lower voltage for leds. Leds are connected in series, driver has click switch mounted on the side - you press on in through the rubber button on top of the light.
2 chips in front of the driver are PIC and MOSFET (these chips weren't present on TC750X flashlight driver, so BL20 uses another, more powerful driver), large inductor on the other side, underneath it are some small SMD resistors/capacitors.
ELECTRONICS
Manufacturer specs for this light are:
Current draw:
Standy (battery connected, light turned off) - 0.007A (driver draws a very small current from battery in standby, so be sure to disconnect the battery if you're not going to use it for a long time)
Low - 0.074A
Middle - 0.638A
High - 2.285A
Strobe - about 1.3A, basically high mode with strobe.
These numbers confirm the manufacturer specs. While they're a bit overrated this light should be able to give about 1300-1400lumens in high mode. Runtimes are also correct (it should actually work for 50-60 hours in low mode).
I also really like the modes arrangement. Low mode is your parking light, useful for city conditions when you only need to make yourself visible without blinding everybody in front of you. It can also be used on an almost discharged battery to give yourself a few hours runtime to get home. High mode is VERY high and gives huge amount of light - considering that BL20 uses XM-L2 leds it could have the highest output of all 2 XML lights. Strobe mode is hidden and activated with a doubleclick.
Battery indication - as you can see this light has no visual battery indicators (green-red leds usually placed behind buttons on other lights), but its not a problem at all. Buck driver used in this light can only regulate output as long as the input voltage is higher than the voltage on leds (Vf, about 3.2v) - so as soon as the battery voltage drops under ~6.4-6.6v (about 20% of remaining battery capacity) you'll notice a brightness drop. Brightness will then start dropping to zero and you'll have enough time to notice that and switch the light to low mode (which is really low and will give you a few more hours of light) or replace the battery with a new charged one.
For example current draw from battery at 6.0v is:
Low 0.02A, middle 0.18A, high 0.89A - brightness is about 3 times lower than on full battery and its very easy to notice that.
BEAMSHOTS AND BRIGHTNESS
This section will be added later, I'm currently building a database of brightness measurements with my light meter. Beamshots in the city/forest will also be made later, for now here is a simple beamshot on the ceiling:
Beam profile is good - wide hotspot with smooth transition to the spill area.
CONCLUSION
Shadow BL20 turned out to be a very good light. Its not perfect, uses too many custom parts, not made for any modifications. But it has a nice mount, good battery (and believe me, good battery is a very rare thing for chinese lights), good UI, XM-L2 leds with a very high output in high mode and a case that can handle heat from such leds.
Its more expensive than other 2 XML lights, but in this case price increase is worth it for the battery alone.
Personally I wouldn't buy it because I like to replace leds with warm white leds in all my lights - but I can recommend it for others.
Shadow BL20 was bought here:
https://www.fasttech.com/p/1359100
This light is sold only in 2 stores and nobody seems to have it, so there is no information about it anywhere. Lets fix this
«Shadow BL20» all pictures are available here, you can also view high-res originals (click on any picture, bottom-right corner will list all resolutions, use google translate if needed)
PACKAGING / CONTENTS
Simple cardboard box, with Shadow sticker on the top and small sticker with model name on the side:
Box arrived slighly damaged, but light and contents were ok. Here is what you get in the box, protected by 2 layers of foam:
Light, battery, charger, extension cable, manual. You can find pictures of manual in the main album, if somebody can translate it - please post translation in this thread.
DESIGN
First of all - its basically a Shadow TC750X flashlight with bike mount, you can read detailed review about it here:
SHADOW TC750X (2 x XM-L U2 | 2 x 18650) Review
But there are some modifications and differences which I'll describe later.
Light dimensions: 65x60x35mm (without mount), weight: 170g. Its a bit larger and heavier than most other 2 XML lights, but still small enough to be used on bike. Here is a comparison pic with my other 2 XML lights:
It also has a larger reflectors than other lights:
This should give it a bit more throw.
Light has nice CNC-machined body with grey/titanium finish, looks very good and different from the usual black lights. Bezels are made from stainless steel, body is made from aluminium, its big and heavy enough to handle 2 high-current leds.
It also has a very interesting custom mount - its a 2 piece design, made from sturdy plastic:
Its attached to the light with 1 hex screw with a rubber spacer to keep it in place. You can also rotate light head from left to right if needed.
To attach it to handlebar you simple unlock the mount, place it over the bar and lock it by moving the bottom part up. It has ratchet-style locking mechanism, with a row of teeths on upper side and a pawl on bottom - which work very well and very fast. There are also 2 rubber inserts glued to mount which will grip the bar and prevent light from sliding up/down, here is how it looks when attached:
Overall - very nice mount design, I really like it. Can be attached/removed in a few seconds to handlebars from 32 to 22mm.
BATTERY
This light uses custom connectors for battery, with 2 small pins side-by-side in the connector, rubber o-ring for water seal and screw-on cap to prevent disconnection. This connector looks very simular to Niteye connectors and while completely non-standart it works very well, here is it compared to Niteye B20:
Light and battery have 2 very short cables attached to them - this is intentional and made for mounting light and battery close to each other (for elight on the handlbars and battery on the stem). There is also a long extension cable if you need to mount the battery further from light.
Battery is a simple 2S2P pack made from 18650 cells, most chinese lights use such batteries:
Battery capacity is marked as 4400mAh, actual capacity measured on my Imax B6 charger at 0.7A current was about 4700mAh, here is a discharge graph:
Battery protection activated at 4.5V, which is good for this light since it depends on low discharge for battery indication (explained later in the review). Battery can also handle 3.5A charge and is probably made from good cells unlike most other chinese bike lights batteries.
But battery is not protected from water! Be sure to give it additional protection by wrapping in plastic bag/rubber balloon or something, this is very importand - or it could be damaged in the rain.
UI
Simple UI, controlled by the button on top of the light. From turned off state one press of button wil turn on the light, modes are switched with single click between 3 levels (Low, Middle, High). Double click will turn on strobe mode, single click in strobe mode will return light to previous constant-light mode. To turn off the light hold down the button for a few seconds. There is no mode memory so light is always turned on in low mode.
TEARDOWN
Lets try to open it up and see how its made :thumbsup:
Starting from the front its possible to unscrew the bezels, then remove the glass and o-ring under it, then remove the reflector:
Interesting thing - reflector has orange peel coating, is made from aluminium and actually has threads on it, so you have to unscrew it from the body:
Led inside the light:
This light uses XM-L2 leds which are about 10-20% brighter compared to the XM-L. Leds are mounted on 20mm stars, stars are glues with thermal glue/thermal silicone to the body. Mounting looks very nice and clean, with just the right amount of glue and will give the perfect thermal transfer to outer case. Unfortunately this also means that its almost impossible to replace the leds, this thermal glue is VERY hard to remove (I tried to do it on other lights and usually its impossible to remove glued stars).
We won't get inside from the front, so lets assemble the reflector and try from the back:
Back cover was very hard to unscrew, threads are covered with same thermal silicone. From the view inside you can really see that its just a flashlight modified for bike use - 2 wires are soldered to battery connectors. Battery cable is also fixed with a zip-tie, that should protect it from pulling from the case.
Next step - unscrew the retainer ring, again very hard to do with threads covered in glue. This gives us access to the driver:
And unfortunately thats where I'll have to stop the teardown and I won't be able to measure current on the leds
This light is clearly not made to be taken apart, everything is glued together, wires are too short to unsolder from driver. I could cut them and remove the driver but then it'll be very hard to assemble it...and since I paid for this light myself I don't want to destroy it.
Some notes about the driver - its a usual buck-type driver, converts high voltage from battery to lower voltage for leds. Leds are connected in series, driver has click switch mounted on the side - you press on in through the rubber button on top of the light.
2 chips in front of the driver are PIC and MOSFET (these chips weren't present on TC750X flashlight driver, so BL20 uses another, more powerful driver), large inductor on the other side, underneath it are some small SMD resistors/capacitors.
ELECTRONICS
Manufacturer specs for this light are:
I won't be able to measure current on leds to confirm them, so lets try to measure current from battery. Current is measured on UT61E multimeter using custom-made 18AWG cables with very low resistance. Battery was about 90% charged.
Current draw:
Standy (battery connected, light turned off) - 0.007A (driver draws a very small current from battery in standby, so be sure to disconnect the battery if you're not going to use it for a long time)
Low - 0.074A
Middle - 0.638A
High - 2.285A
Strobe - about 1.3A, basically high mode with strobe.
These numbers confirm the manufacturer specs. While they're a bit overrated this light should be able to give about 1300-1400lumens in high mode. Runtimes are also correct (it should actually work for 50-60 hours in low mode).
I also really like the modes arrangement. Low mode is your parking light, useful for city conditions when you only need to make yourself visible without blinding everybody in front of you. It can also be used on an almost discharged battery to give yourself a few hours runtime to get home. High mode is VERY high and gives huge amount of light - considering that BL20 uses XM-L2 leds it could have the highest output of all 2 XML lights. Strobe mode is hidden and activated with a doubleclick.
Battery indication - as you can see this light has no visual battery indicators (green-red leds usually placed behind buttons on other lights), but its not a problem at all. Buck driver used in this light can only regulate output as long as the input voltage is higher than the voltage on leds (Vf, about 3.2v) - so as soon as the battery voltage drops under ~6.4-6.6v (about 20% of remaining battery capacity) you'll notice a brightness drop. Brightness will then start dropping to zero and you'll have enough time to notice that and switch the light to low mode (which is really low and will give you a few more hours of light) or replace the battery with a new charged one.
For example current draw from battery at 6.0v is:
Low 0.02A, middle 0.18A, high 0.89A - brightness is about 3 times lower than on full battery and its very easy to notice that.
BEAMSHOTS AND BRIGHTNESS
This section will be added later, I'm currently building a database of brightness measurements with my light meter. Beamshots in the city/forest will also be made later, for now here is a simple beamshot on the ceiling:
Beam profile is good - wide hotspot with smooth transition to the spill area.
CONCLUSION
Shadow BL20 turned out to be a very good light. Its not perfect, uses too many custom parts, not made for any modifications. But it has a nice mount, good battery (and believe me, good battery is a very rare thing for chinese lights), good UI, XM-L2 leds with a very high output in high mode and a case that can handle heat from such leds.
Its more expensive than other 2 XML lights, but in this case price increase is worth it for the battery alone.
Personally I wouldn't buy it because I like to replace leds with warm white leds in all my lights - but I can recommend it for others.