Magicshine MJ-818 3W rear light

[103Alex1]

Got one of these in an e-bay auction minus battery pack as I'm wiring it in. Impressed actually. Really small and very bright :

I can't mount on my seatpost as the light would be covered up so I adapted one of these to screw on to the mounting plate on the back of my rack :

A T bar to fix your lights to.

Cut it down and swapped out the base plate for one of these mounts to fix it on to the bar :

Swivelmount for Magicshine / Inton / Fluxient / Starlight etc bike lights | eBay

I epoxied the slot-in light holder that came with the rack to the cut down bar :

... so I can easily attach my back-up battery-powered Smart Lunar 2 x 1/2W rear light if the built-in one fails or has to be turned off (e.g. if bike battery very low) :

There room to mount a second MJ-818 (not that you'd need it) ... or even (shock, horror) ... a rear reflector on the other side of the bar to keep all boxes ticked. Can't see any possible purpose to a reflector with lighting like that to be honest, but I don't make the rules !

The little bar attaches to my rack via a bolt from the rear into the cut down tubethat the emergency back-up light slot plate is epoxied to, held in place via a tricky to insert nut. But it works - and when I mount it, it can stay attached to the rack - as everything else can be removed.

Pleased with that.

 

[Old_Dave]

Pleased with that.

If all your lights are on... don't stop close to an airport

 

[amigafan2003]

I had one of them but the wiring was terrible - if you get the chance unscrew it and take a look at where the wires join the circuit board and resolder them.

I've now got one of these instead - can use the same battery pack.

 

[cwah]

I'm interested in this set up. My rear led light from Hobbyking are really nice and shiny but not powerful enough (for me).

Just a couple of question:
- Are you wiring it to a 12V battery? (that's my plan)
- And is blinking automatically?

I want to be seen from... FAR!


ps: this one?
Magicshine MJ-818 Cycle rear Bike light + Y splitter cable for MJ-880 880U 880E | eBay


thaaaanks

 

[50 Hertz]

I'm interested in this set up. My rear led light from Hobbyking are really nice and shiny but not powerful enough (for me).

Just a couple of question:
- Are you wiring it to a 12V battery? (that's my plan)
- And is blinking automatically?

I want to be seen from... FAR!


ps: this one?
Magicshine MJ-818 Cycle rear Bike light + Y splitter cable for MJ-880 880U 880E | eBay


thaaaanks

The light requires a nominal input voltage of 8.4 Volts. It will work at 9 Volts which is the output of the DC-DC convert linked to above. I would not try to connect it directly to a 12 Volt supply, you may damage it.

The light operates in 3 modes, 2 of which are flashing and one steady. The light start in a flashing mode and you rotate the bezel to scroll through the other modes, steady being the final one.

The unit you link to is the correct light.

 

[cwah]

I have the MJ-880 that was supposed to be working on 8.4V too, but I plugged it to my 12V converter and it works fine

Apart that it suck a hell a lot of battery!! between 20-30W!! lool


It's very light, but way too focus, so not that useful apart from blinding cars and cyclist around me

 

[103Alex1]

I'm interested in this set up. My rear led light from Hobbyking are really nice and shiny but not powerful enough (for me).

Just a couple of question:
- Are you wiring it to a 12V battery? (that's my plan)
- And is blinking automatically?

I want to be seen from... FAR!


ps: this one?
Magicshine MJ-818 Cycle rear Bike light + Y splitter cable for MJ-880 880U 880E | eBay


thaaaanks

Hi cwah.

Yes, that's the one. There are 9 small LEDs which can flash or stay constant along with a 3W LED in the centre. You will be seen from VERY far ! The light has a rotating bezel which you turn when you first open the power supply through 3 modes.

There are 2 flash patterns to go through first, but the brightest by far is just to select all LEDs to stay on. When set in that mode there is no blinking, just a very bright light. Like all 'multimode' lights, you have to select the mode you want at the light once the power supply is opened. Then if you turn off for more than about 5 seconds, you need to reset manually by rotating the bezel.

I am running this together with a CREE T6 3-LED front light off 36V battery with supply stepped down to 9V (to approximately match the voltage from the battery packs these lights usually use - which is 8.4V). I think 12V may be a bit high for these lights - but I haven't tried it as they're a bit expensive to blow up !

The rear light was drawing 0.14A from 36V battery on full power (constant) and 0.3A measured after the 9V DC-DC converter.

My powered handlebar switch supplies 36V to the 3A HRD DC-DC converter which supplies these lights (but a direct wire tap would do the same thing).

I used the Y-splitter cable that comes with the light to branch the power supply out of the other side of the voltage converter (I cut the connector off the Y-splitter cable and attached the wires to the 'out' +ve & 0V slots from the voltage converter). This light plugs into one female connector and the front light into the other. If you don't want 2 lights off the same converter then you can just wire the light straight to the voltage converter.

EDIT :- just seen posts above whilst typing this.

 

[103Alex1]

I have the MJ-880 that was supposed to be working on 8.4V too, but I plugged it to my 12V converter and it works fine

Apart that it suck a hell a lot of battery!! between 20-30W!! lool


It's very light, but way too focus, so not that useful apart from blinding cars and cyclist around me

The 3-CREE lights are very bright (see 'brightest possible front light' thread) ... but I fit with these so they do not make such a concentrated beam - it is more like a car headlight pattern :

Wide Angle Lens for Magicshine, Lupine and Gemini Bike Lights | eBay

Using 2 single CREE T6 lights will definitely get you seen, without being so blinding to oncoming vehicles, especially if you angle them down a bit / use wide angle lens and are riding in London (do not need off-road lighting to see with in areas with street lights). They are so much cheaper than those MJ-880s which are only useful off-road or on completely unlit roads. Waste of money (and battery) otherwise !

One of these either dropped vertically down or out will happily take 2 x single-CREE lights and takes about a week to arrive :

Bicycle Bike Handle Bar Extension Expand Light Speedometer Mount T Type | eBay

Torchy sells the mounts :

Swivelmount for Magicshine / Inton / Fluxient / Starlight etc bike lights | eBay

 

[cwah]

Agree that these MJ-880 are a bit of a waste of money... as it's a strong focus so not really useful. I like the idea of the double single T6 CREE but I'll still keep my MJ-880 as I paid quite a lot for it. And also because they have the strong benefit of being compact.

I added so many gadget over time on my brompton that now everything I want to add has to be quite small or cleaver. It's easy to add, but very difficult to keep it clean!


I think I'll still have a try on 12V on the light. I did it on few 8.4V light and they all worked fine.

Is this one the cheapest and BEST I can find?
Magicshine MJ-818 Cycle rear Bike light + Y splitter cable for MJ-880 880U 880E | eBay

Ideally I'd like it to start on blink mode as soon as I turn the battery on.


ps: I've also seen very good review on the Mars Blackburn 4. Apparently it's super bright too. I was wondering if in 3 years any challenger appeared!


Going to buy a new rear light soon

 

[103Alex1]

Agree that these MJ-880 are a bit of a waste of money... as it's a strong focus so not really useful. I like the idea of the double single T6 CREE but I'll still keep my MJ-880 as I paid quite a lot for it. And also because they have the strong benefit of being compact.

I added so many gadget over time on my brompton that now everything I want to add has to be quite small or cleaver. It's easy to add, but very difficult to keep it clean!


I think I'll still have a try on 12V on the light. I did it on few 8.4V light and they all worked fine.

Is this one the cheapest and BEST I can find?
Magicshine MJ-818 Cycle rear Bike light + Y splitter cable for MJ-880 880U 880E | eBay

Ideally I'd like it to start on blink mode as soon as I turn the battery on.


ps: I've also seen very good review on the Mars Blackburn 4. Apparently it's super bright too. I was wondering if in 3 years any challenger appeared!


Going to buy a new rear light soon

Yes I know what you mean about needing things small - you run out of space really quick even on a MTB !!

I haven't seen a Mars Blackburn 4.0 to check it out. The MJ-818 will not necessarily come on at all when you turn the battery on. You have to go to the light and turn the bezel to get it to come on when you power up. This is the only downside - same as with the Cree T6 front lights with clicky switch. But once it is on, it's a rear light and will stay on so it's not too bad.

The one you linked is the cheapest I can find right now too. I bid on one at auction and got it for £21 with a Y-splitter cable and came with proper box and everything but none on auction at the moment.

Btw ... as I already had a Y-splitter, have just finished taking the cable apart - used the female connectors off it on 2 front T6 battery packs (8.4V) which came with those cr*p connectors which are not properly watertight. Now I have total 3 usable 8.4V battery packs for my Kalkhoff that does not have wired in lighting, just a dynamo. So ... when I keep forgetting to charge the battery pack after riding it I can now just pick up a spare .

I also spliced the wire with 'good' Magicshine male connector onto a front T6 light which had one of those rubbish knock-off male connectors on it that isn't tight when connected to the battery - so now happy to use it. Good value from 1 redundant attachment !

 

[cwah]

yeah £21 is quite a good price!

I'm going to put the MJ818 as a keyword on ebay, hoping to have it in auction for cheaper price later

Thanks

ps: I already have all the light wiring set on my brompton. So I don't really need a splitter. But it's always good to have it as I won't have to cut the main wire of the light, so the warranty would still be available!

 

[Cyclezee]

I had one of them but the wiring was terrible - if you get the chance unscrew it and take a look at where the wires join the circuit board and resolder them.

I've now got one of these instead - can use the same battery pack.

I agree with amigafan, it is an excellent light.

A Cyclezee customer has a Bike Ray rear light fitted to his eZee converted bike and he runs it via a DC/DC stepdown convertor from the bike battery.

 

[103Alex1]

^^ that's great but so far as I can tell from searching, they're no longer available - perhaps discontinued ?

 

[Cyclezee]

According to the Bikeray website the rear light are available to buy direct BikeRay Rear Light Extension kit 3 Watt

 

[103Alex1]

Nice one, John - my google searches all led to dead websites and out of stock supplies.

cwah, if you want the BEST rear light, it looks like you found it off John's link .

 

[cwah]

Nice one, John - my google searches all led to dead websites and out of stock supplies.

cwah, if you want the BEST rear light, it looks like you found it off John's link .

Yes but these light seem to have a strong focused light. But is probably not so good at angle.

It's also a part that get easily stolen so I don't want to invest more than 20-25gbp on it. Will wait a bit on ebay until I have one