That's a pretty nice price. Just the batteries is $20.
Jup, at DX the battery pack for MJ-808 is almost 30$ http://www.dealextreme.com/p/velcro-binding-band-for-sku-29489-30864-35cm-32754
Just about to buy this...how has it held up for you so far?
Sweefu, which "this" did you mean? If you meant clone, then I don't know, but know a lot about original MJ-808 (and 808E).
It's held up great so far. Runtime seems good, all charges have stopped at a safe termination voltage and it's still running fine after a number of off-road downhill rides, so it's taken a lot of bumps and jolts. Tint does have a vanilla/green cast if that bothers you but I don't mind at all.
Thanks for the feedback mate!
Just ordered...the search continues for the perfect bike light..
I have been looking through the web for a good bicycle light. I was leaning towards a flashlight and holder solely because it is cheaper than a dedicated bike light, then I came across this thread. This light is at the top of my list now. Do you have any new updates on the light? Does it have the different light color changes on the back button? How is it holding up? Runtimes? oh, also is the cord long enough to just place the battery pack in my saddlebag? thanks in advance for any info.
Hi Rick,
Sorry for the slow reply, I've been away all week. The light on the back does change from green to red as the battery depletes like the magicshine. I haven't done any dedicated runtime tests until it goes flat yet but it has easily passed the two hour mark on cumulative rides with no issues, I am assuming 3 hours is accurate and the cells are 2200mah.
The cord is very long actually, I have to wrap it around the bars a few times to pull in some of the slack. I think it could reach a saddlebag. I would highly recommend this for anyone looking for a dedicated bike light even if they aren't on a budget.
Ok, a few more thoughts now it's been in use a while.
The light does not go Green/Orange/Red like the Magicshine. It shows a green led until the pack drops to 7v (3.5v per cell) then the red led comes on with the green one also. After it drops below 6.6v (3.3v per cell) the green goes off and only the red is on. Once this happens you only have a few minutes before the light cuts off, there is no low voltage dimming, so not ideal. I don't mind as I always have a helmet light and a spare bar mounted XP-G solarforce so I won't be left in the dark, but it doesn't give enough warning to be confident about using on it's own.
The output seems to drop after a while of use slightly, from over my Manafont XM-L at 4.2v (T6 at around 3A) to slightly less than it. I'd guess around 600 OTF. This is matched by very long runtime however, while doing the rear led tests it took hours to cut-off, I wish I'd been measuring but it was a long time.
Also, my charger has started playing up, going to green led (indicating fully charged) when the pack is at 7.5v, so only about half charged. I unplug and try again and it goes green after a few minutes again. This is irritating, I have since taken the housing apart and it now seems to work fine just hanging out with all the electronics visible, time will tell once I put it back together again I guess.
Overall, it may be worth going for the official MJ-808e from DX at $78 for the better quality build, (strobe is also slower on that and less annoying and likely to cause seizures in unsuspecting drivers) but this is still a good bright light for a very cheap price.
Thanks, I don't think that is the issue. I'm guessing the charger measures the pack's overall voltage when determining if it's fully charged or not (I'm not expecting proper CC/CV phases at this price). So with it terminating so soon it must be a charger fault.
Interestingly I reassembled the charger and after a few minutes (now at 7.6v) it said again it was fully charged. I dissasembled again and it's now happily charging again. I don't understand how the orientation/position of the charger could have an effect on early termination but it seems to..
I also found out what 12v 1A output feel like through my left thumb, it wasn't too bad actually. But I'll be trying my best not to do it again.
Magicshine battery pack has also protection circuit which causing problems to me about one year ago. I couldn't charge the batterie at all. It lit red (charging) for a second or two and then went to green. Trying all combinations with my friends battery pack and charger I found out it's electronics on battery back. Later I've got electronic from one guy who had bad cells. See pictures at http://www.mojalbum.com/mmilan/baterije-in-elektronika-za-lucko-magicshine/prvotni-original/17916489/povecaj - click on picture to move to next. I've made may own spare battery pack just in case - https://picasaweb.google.com/mojmailbox/BaterijskiPaketZaLuckoMS.
That was crucial time - beggining being addicted to flashlights 
That's how laptop cells charge, too. Not a problem if properly engineered, though I somewhat doubt that for a $60 basically at cost light.
All the charging related electronics are on the battery pack. I've seen cells in parallel (and series).
I don't have problems with battery pack since I've changed protection circuit and I've got spare one from the Magicshine manufacturer. It took half of the year to get it. I should pay enormus amount for shipping, but managed to get it as add on in a bigger shippment for some local bicycle store.
@Triker, did you look all my pictures. First is original circuit that failed, then at the end is replacement from some other pack with bad cells. http://www.mojalbum.com/mmilan/baterije-in-elektronika-za-lucko-magicshine/prvotni-original/17916489/povecaj#17916491. Probably quite different from ordinary battery PCB.
I've taken apart few laptop packs - all with quite alot electronics inside. All were 2P3S load balanced in pairs.
IF someone knows where to get just the host of the emitter i am all ears. :)
I'm looking at the pics and it seems the 2 cell pairs are then wired in series, so I assume the light has to be regulated with this 8.4v total arrangement?
Yes, it's 2P2S wireing which outputs 8.4V at max. Pairs are crosswired so there is combination of 4 flow paths. In that case you can still get 8,4V if one or even two cells fails (one in each pair). Of course you won't recognize failure until you measure the current, I think.
Bear in mind, Magicshine only offer 180 days warranty on batteries and chargers (not even half a year!)
Bear in mind, Magicshine only offer 180 days warranty on batteries and chargers (not even half a year!)