Mountain Bike Reviews Forum banner
1 - 9 of 9 Posts

·
Registered
Joined
·
22 Posts
Discussion Starter · #1 ·
The batterypack for my magicshine went dead over summer.
Nothing happens when I put it in the charger.

Is there some way of kickstarting it again - or is it just plain dead ?
 

·
Registered
Joined
·
107 Posts
Well, you can always try the 'jumpstart' method to see if you can re-activate the original battery pack.

This typically works when a pack has self discharged to the point where the voltage is below the level required for the built in electronic monitoring to function. When this happens, the electronics 'trip' disallowing any charging. By 'jumpstarting' the pack, you inject enough voltage for the pack to get above the minimum threshold allowing the protection circut to reset... allowing normal charging afterward.

HOWEVER, if the pack drained due to a faulty cell and you manage to jumpstart it, and then try a normal charge cycle - you take the chance of creating a pack with a VWF (vent with flame) condition i.e. infamous battery bomb.

Might be interesting to try it out for fun... outside away from anything flammable with appropriate caution (and at your own risk of course).

FROM AN INTERNET SITE (which we know is always true and correct) :D:
Took a 12V power supplyand touched the poles of the dead battery with that to trickle charge it. The actual Li-ion battery for the device is rated at 3.6v.

After the first 10-20 second revival charge, the meter read 0.5v or something. After a few more cycles, it read 2.5v.

At that point i mounted the battery back to the device for a proper charging with the unit's charger.

After about an hour or more it stopped charging and I tried the unit off the battery. It works.


WITH THIS WARNING:
I do a lot of work with Lithium ion battery packs. We have had more than a few of them burst into flames during charging. It is not something you want to witness inside a building or vehicle. This is usually due to corrosion or some other imperfection inside the roll.

In the real world they have a useable life of about 1 to 2 years regardless of number of cycles. They will self discharge to a point that they need to be jump started, but usually that is due to the monitoring circuitry that is typically in the pack not having enough energy to run and thus not allowing any charge current into the cells. In our battery packs we actually have current and voltage limiting devices as well as real time individual cell temperature and voltage monitoring to prevent charging outside of acceptable parameters. The circuitry also has the ability to completely and permanently disconnect the cells from one another in a catastrophic event to keep damage to a minimum. This is all backup to the circuitry which is in the charger.

Normally to jump start a battery we will supply it with it's operating voltage, or slightly higher at a medium current rate (depending on it's capacity) and carefully monitor the batteries temperature. Usually they only need 10-20 seconds to get enough of a charge to allow the devices built in charging circuitry take over and work.

What you are describing is pretty dangerous. I would not recommend jumping it again unless you are outside and wearing glasses.


P.S. Night before last I was helping my son with a homework project and he had every sort of school "project" supply laid out on the den floor... T-square, protractor, curves, construction paper, glue, foam core, markers, etc. etc. etc.

Over in the corner by the supply bin, heard some odd noises... yelled at the cat to stop messing with the project stuff. Cat looked at me like I was stupid :skep: and kept swatting the markers around.

Then I decided the rukus sounded more like a 'sizzling' and 'popping'... funny thing is, cats playing with markers don't usually make a sizzling or popping sound.

When the sizzling and popping got louder and turned into large puffs of noxious smoke - I yelled at Matt to get the Halon fire extinguisher while I ran to grab a large pot from the kitchen and thusly kicked the recalcitrant battery pack that was charging in the other corner into the heavy pot in case it decided to blow up... which appeared to be imminent.

I watched the pack vent on the patio for a good 5+ additional minutes before deciding it wasn't going to go full Chernoble. Good thing we have a whole house fan and was able to vent most of the noxious fumes in 10 - 15 minutes. My son posted on Facebook I almost burned the house down (only slightly melodramatic)... and I told him since his project didn't go up in flames he needed to finish it - he wouldn't get to use the old "my dad blew up my project with an exploding battery pack" excuse.

ANYWAY, DON'T TAKE CHARGING ANY TYPE OF BATTERY FOR GRANTED... STAY SAFE MY FRIENDS!
 
1 - 9 of 9 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top