OK I will try to keep this brief....

I was a relatively early adopter of the MagicShine 900 Light, purchased from GeoManGear last November. I was very very pleased with the light.

I used it once/week (occasionally twice/week) for my commute. I was a little concerned when I noticed, after a few weeks, the burn time went from 3 hours to approx 90 minutes (on high)....but my commute is only 40 minutes each way so it wasn't that big of an issue.

I waterproofed the battery with saran wrap....but it NEVER got wet.

Anyway, I used it for approx 5 months, then springtime and daylight savings time rendered it unnecessary the past 3 months.

Just for fun, I tried using the light a few days ago and it did not work. I put the battery on the charger, and it stayed green....it would turn red for a few seconds at a time if I jiggled the connection, but even after doing so the light does not work. And the LED on the back of the light is dead also.

So I have several questions:

1. I believe the problem is the battery, but I suppose it could be the light or the charger. I have limited technical knowledge, any easy way to "prove" it's the battery??

2. Assuming the battery is the problem, does it make sense to get a new battery or just get a whole new system? I imagine the next generation of the light is probably better with respect to water resistance, shorter cord (mine has the super long cord which is redundant, although I don't really mind it all that much).

3. I doubt it, but do I have a grievance against the maker of the battery? I am sure it is long out of warranty.

4. Is this a common problem? I suspect not, as there is another thread asking about feedback on the battery and no negative comments.

All answers/suggestions are appreciated.

Doug

Do you have a digital VOM (volt ohm meter)? It will help if you have one even if it is a cheap unit. You may want to first check it at the charger output to make sure it has a voltage of about 8.4 volt. Then take a voltage reading of the battery. At the minium, it should read 7.4 volt which is the cutoff voltage of the protector. If that reading is sporadic with wiggling the wire, then it might be a bad wire or protection board on the pack. Same with the charger. If you have an Y adapter, you can also hook that up while the charger is on the unit and test the voltage at the unused plug of the Y adapter. You should be getting some kind of voltage like 7.4v and a slow increase as it is being charge.

The batteries are in parallel and so don't charge correctly. If the cells aren't really nicely matched they will slowly get out of sync (one charging or discharging more than the other each cycle).
Yes its a design feature of a cheap battery/charger. I would expect to be buying a new battery every year if you want the full runtime.

It is probably worth emailing geoman if you think you're hard done by.

+1 for Geoman's customer service....I just emailed them and they are sending me a new battery, no charge (pardon the expression!).

Doug

I have the same MS unit, got it and used it about the same time. By charging it once a week, I probably have 25 charge cycles total. Now that I do not need it for light, I still charge the pack once every 8-12 weeks.
I just tried the MS over the weekend and it worked fine. I think the 4 batteries (18650) in the pack are series-parallel, so it could be true that they do not always charge the same. I have had this happen with other headlights, flashlights using NiMH AA batteries. The AA's were wired in series to get <6V, and one weak one would kill the light or make it very dim. Once I got a good charger, I could weed out, or refresh the individual weak batteries.
For the MS, it would be nice to be able to charge and check individual 18650 batteries, I guess you could convert it to a DIY pack with individual wires coming out for each battery.
Anyway, for me, so far so good with the MS battery.... we'll see this fall.

Another possibility could that you have a bad connection somewhere. Especially since you noticed a "red light" flashing on when attempting a charge.

I guess the new battery will "solve" the problem. But on the other hand, you should make a special effort to to "time" a couple of charge cycles and actually see how long it takes your new battery to be brought up to "green" voltage level. That way you will know how long a normal charge cycle takes.

Most likely a bad connector. I worry about damaging mine every time I pull it apart, since it takes a lot of force (and care) to do without damaging anything.

By the way, my battery life went down from 3 hours to about 90 minutes in the dead of winter, and is now back up to something close to 3 hours again in the warmer weather. 9 months, at least 50 charging cycles, still fine.