How to reset battery protection?

I sold my Olight M30 to a buddy at work and he ran the batteries (2 18650s) until one of the protection circuits kicked in (until the light shut off). Now, one of these batteries will not register on the charger and the charge light stays green and won't go into charge mode (Ultrafire wf-139). I believe it is the battery protection because the other is fine and the light works with this battery switched out for another. It is a protected Ultrafire (2400 mah, the grey one). Does the 139 trickle? I had the idea of leaving it on the charger overnight to see if it will kickstart. For future, I told him not to run these batteries down and to recharge frequently. Any advice?

Edit:

I'm adding this here so it's viewable in the first post of this thread - Norm

oKtosiTe said:

Sounds like the protection got tripped. If your charger is an i4/i2 or similar, it will not reset the protection (not true, read below), but HKJ's famous hotwire action should:
(Edit: only do this for a few seconds at most!)

(This assumes you still have one working, charged Li-ion battery.)

Click to expand...

Usually the protection circuitry will reset if you leave it in the charger for a short bit. If it doesn't reset, it might be shot. I know AW's cells reset in the WF-139 (open voltage ~5V), the Ultrafire cells might be different. Might be worth it to pick up some new AW cells.

The WF-139 charger info states it will not charge batteries that have gone into protection mode.

You simply have to take the battery up to a higher voltage through something that has limited current to get it "started" so to speak. I had an old 12V DC converter, one of those old power converter transformer with a DC output that went into a small device like a radio. Current output of that one was limited to about 500mA. I put it across the battery terminals for about 10 seconds and then put the battery back into the Ultrafire charger and then it would charge normally and did in fact charge up.

I had already tested the output of the converter exposed wires to make sure I had the polarity correct using a digital voltmeter. You can use a variety of DC voltage sources as long as you have something to limit the current.

For instance you can take 2 other batteries of double the voltage and run them in series through a 40 ohm resistor that will limit current. Connect positive to positive terminals through the resistor and negative to negative. The 2 battery stack of lithium ion batteries will go up in voltage to the single cell battery but the resistor will provide ballast once it starts to draw current and protect all 3 batteries. You only need to do it for a few seconds.

If you had a DC voltage power supply with current limiting capability that you could simply set to about 100 mA limit and raise the voltage until you saw it draw current to the battery in question that would be the best way, but I am guessing you don't have it.

Do not try and go from a high current capable source directly to your battery without some type of resistance to limit current flow. Bad things will happen.

By bad I'm assuming you mean "vent with flame" or similar. I have a li ion charger for my li-po airplane batteries I will try and give it a "shock" with for a few seconds. Are there any chargers that will reset these cells? There don't seem to be many options out there.

find yourself any power supply which limit current to below 2A
mobile charger might do the job ( >5v )

bkumanski said:

By bad I'm assuming you mean "vent with flame" or similar. I have a li ion charger for my li-po airplane batteries I will try and give it a "shock" with for a few seconds. Are there any chargers that will reset these cells? There don't seem to be many options out there.

Click to expand...

None of the battery chargers I have found for the lithium ion batteries that charge 1 cell at a time will charge a cell that has gone into protection mode. Your adjustable voltage charger for li-po battery packs that can go up to higher voltages should work. You should have current limit protection and be able to set the amount of current you want to deliver to the battery, correct? If so limit it to about 200 mA.

but again, this isn't to fully charge the battery, this is just to kick it back into normal mode. Once it will start taking a charge put it on the WF-139 and let it charge properly and auto shut off when it peaks out.

bkumanski said:

Now, one of these batteries will not register on the charger and the charge light stays green and won't go into charge mode (Ultrafire wf-139)

Click to expand...

Had the same problem and found out that the WF-138 will charge them.

Robert.

I dont know if this is the right or wrong way but here's what I did with my grey trustfire... and it seems to have worked. I just connected the cell to a 3.6V 350mah wall wart power supply. I just let it charge up for ~5 minutes to get the cell voltage up a little and jump start it again.

I am not sure about ALL versions of WF-139. Mine is a version 2.0, and it will not attempt to charge any cell that measures below 2.75V, protected or unprotected. So I make certain to NEVER deplete my cells that low in the first place. The one time I did, I just used the above method to force-charge the over-depleted cell on the wall wart and get it back up to ~3V. Once I did that it was OK.

asfaltpiloot said:

Had the same problem and found out that the WF-138 will charge them.

Robert.

Click to expand...

Is any company selling the WF-138 charger today? I haven't seen them anywhere.

MrGman said:

Is any company selling the WF-138 charger today? I haven't seen them anywhere.

Click to expand...

battery junction
e-lectronics.net

http://www.batteryjunction.com/wf-138.html

http://www.e-lectronics.net/ultrafire-wf138-dual-voltage-rcr123-liion-lifepo4-charger-p-377.html

both have them in stock... according to their www sites.

I just pulled this off the WF-138 info page that you linked.

"Perfect charger for rechargeable Lithium-Ion cells. Automatically charges them to the level required, will not over-charge cells. Over-discharged cells cannot be charged."

It gives the same statement about not charging over discharged cells as the WF-139 and other Lithium Ion battery chargers I have seen. So I don't know if this is guaranteed to work, especially on protected cells.

So I am still :thinking:

kramer5150 said:

I am not sure about ALL versions of WF-139. Mine is a version 2.0, and it will not attempt to charge any cell that measures below 2.75V, protected or unprotected. So I make certain to NEVER deplete my cells that low in the first place. The one time I did, I just used the above method to force-charge the over-depleted cell on the wall wart and get it back up to ~3V. Once I did that it was OK.

Click to expand...

Sort of defeats the purpose of protected LiIon's, which is to cut off current when voltage drops too low, so you can save the battery, and recharge it. A LiIon charger SHOULD be able to charge a LiIon cell that has shut down when the protection circuit is activated. Useless otherwise, and if you are going to monitor your LiIon cells so they never drop too low, then you might as well use unprotected LiIons with their advantage of higher mAh's, and higher current potential.

Bill

I agree Bill that would make sense, but some how there is this contradiction. However, since I know how to over come it and its only a minor inconvenience for me I haven't looked into it too much or worried about it for myself. I have numerous DC power supply sources and resistors and meters so its not a problem.

But you would think that the people who make chargers would make them specifically to recharge a "protected" cell that has gone down into protection mode and other wise appears as an open circuit or something that a normal charger won't touch. :shrug:

Bullzeyebill said:

Sort of defeats the purpose of protected LiIon's, which is to cut off current when voltage drops too low, so you can save the battery, and recharge it. A LiIon charger SHOULD be able to charge a LiIon cell that has shut down when the protection circuit is activated. Useless otherwise, and if you are going to monitor your LiIon cells so they never drop too low, then you might as well use unprotected LiIons with their advantage of higher mAh's, and higher current potential.

Bill

Click to expand...

Well... no one has ever said the WF-139 was a perfect charger... even the older revision 1 and 2 models. Ideally it should be able to detect those cells that have tripped, or give the operator the option to "force charge" the cell. But that probably be far too risky, if someone were to mistake a fully charged cell for a fully discharged one.

One of my favorite RC hobby chargers has a user selectable "recovery" mode for those times the cells are over-discharged. It locks out the peak charge detection and forces current across the cell. I have never had to use it though. Some of my RC battery packs are in the $60 range... so its a costly mistake in that hobby to over-discharge your cells. I guess my retentive-ness with CPF cells is a carry over from my days racing RC cars.

Bullzeyebill said:

Sort of defeats the purpose of protected LiIon's, which is to cut off current when voltage drops too low, so you can save the battery, and recharge it. A LiIon charger SHOULD be able to charge a LiIon cell that has shut down when the protection circuit is activated. Useless otherwise, and if you are going to monitor your LiIon cells so they never drop too low, then you might as well use unprotected LiIons with their advantage of higher mAh's, and higher current potential.

Bill

Click to expand...

They are so "Protected" you can never use them again...I guess they are protected from the user? I'll try the force charge tonight. I have another source to attempt it that's only 200mah and 4 volts. Let the kick start begin!

I always considered a battery with protection that has activated & can not be charged back up was because of a faulty or cheap protection circuit? I had some Trustfires that did this. Every single AW protected cell that I have that was discharged to the point where the protection circuit has activated all charged back up fine in my WF-139. IIRC I had an AW protected cell well the protection circuit activate & cut power from the cell. Then the moments later or the next day the protection circuit unactivated & there was power again momentarily until the circuit activated again (put the cell back into a light by accident).

MrGman said:

I just pulled this off the WF-138 info page that you linked.

"Perfect charger for rechargeable Lithium-Ion cells. Automatically charges them to the level required, will not over-charge cells. Over-discharged cells cannot be charged."

It gives the same statement about not charging over discharged cells as the WF-139 and other Lithium Ion battery chargers I have seen. So I don't know if this is guaranteed to work, especially on protected cells.

So I am still :thinking:

Click to expand...

I can't really explain why, sorry.
I have both chargers (WF-139, WF-138) and when the 139 refused the 138 did'nt make a point of it and charged the cells.
Maybe the 138 is less "intellegent"?
The WF-138 with 2 or 4 cells can be had at ebay for a few bucks.

Robert.

It would be nice if someone came up with the correct voltage and amperage wall wart connected to a 18650 battery holders (I see this in B/S/T now) and sold it as a package as a protection circuit resetting device. Maybe a modest money-maker for someone with the skill set.

Actually, I solved this problem with a very simple solution. I took a short piece of dual strand wire (like small speaker wire) and matched ends on a fully charged cell and the "protected" one. 5 seconds later, its up and running. Easy fix with no odd dc chargers.

"Improvise, Adapt and Overcome" :thumbsup: