Can I charge these batteries with my WF-139?

[airtight_python]

I have some Wama 3V RCR123As 600 mAh. I don't know if they are protected. Can I safely charge them on the UltraFire WF-139 with spacers?

Output on the UltraFire WF-139 charger is 4.2V - 400mA.
Output on the original Wama PH-123A-3.0A charger is 4.4Vd.c. 360mA.

 

[Beastmaster]

No. Please don't.

If you want a good fire - go ahead. You need a charger that does 3.6v max.

-Steve

I have some Wama 3V RCR123As 600 mAh. I don't know if they are protected. Can I safely charge them on the UltraFire WF-139 with spacers?

Output on the UltraFire WF-139 charger is 4.2V - 400mA.
Output on the original Wama PH-123A-3.0A charger is 4.4Vd.c. 360mA.

 

[Lightguy27]

Yeah, what Beast said. And there is a section for batt questions, (I should know since one of my first questions ended up in General too and was swiftly moved).

-Evan

 

[Steve L]

If they are not 3.6(3.7) rechargeable batteries they will be overcharged. The WF-139 is for 3.6v or 3.7v(4.2v fully charged). You want to use the Ultafire WF-138. It has a switch to charge either 3.6(3.7) or 3.0v batteries.

 

[kavvika]

Wait, wait, don't jump on him just yet. Those "3.0V" cells are actually 3.7V Li-Ion cells with a special protection circuit that bucks the voltage. They're not meant at all for high draw applications, but they're meant to be charged on a charger like the WF-139, so you'll be just fine.

 

[airtight_python]

After what kavvika said... I currently have the batteries on the WF-139 using paperclips as spacers. I am monitoring them closely for signs of venting with fire. The red lights flash and all seems well so far.

 

[airtight_python]

The lights have gone green and I have removed the batteries. No signs of any heat or burning smells. I've started another set. Appears to be fine.

 

[airtight_python]

It's confirmed that the UltraFire WF-139 will charge the Wama 600mAh "3V" Li-ons efficiently and effectively.

 

[DM51]

Please stop doing this.

Beastmaster is right. What you are doing is potentially dangerous, as this charger is not for 3.0V Li-Ion cells.

You are relying on the protection circuit in the cell to prevent a venting incident, and you are overloading it to a considerable extent with an input voltage which is way above what it is designed to deal with. If the protection circuit fails, the cells will be over-charged and you will then have cells reading >4.2V which will wreck any application designed for 3.0V.

Please get a DMM and check the voltage of these cells before you do anything else. If they are reading more than ~3.2V they have been damaged, and you should not use them.

kavvika, please do not give advice unless you know what you are talking about.

This thread belongs in the 'Batteries Included' section, so I am going to move it there now.

 

[LuxLuthor]

LOL! Technically to answer your question: Yes you can charge those batteries with your WF-139. You can also sleep on a bed of rattlesnakes, or brush your teeth with battery acid. I don't know why you asked the question if you already decided to do it. :devil:

 

[Markcm]

airtight_python-

Based on your comment that the original charger is 4.4v, I have confidence in the following:

No you can not fully charge these with the wf-139. This is not an over-charge issue, it's actually and undercharge issue.

Cells that came in the kit with 4.4v charger are standard Li-ion 3.6v behind a voltage reducing circuit utilizing diodes and usually but not always a voltage min/max protection circuit as well. These cells require the extra .2v when charging (hence the 4.4v charger) because of the voltage drop across the diodes. Remember, they did come with a 4.4v charger, right?

You need to use the OEM 4.4v charger to get a full charge, the wf-139 will terminate early for these cells at 4.2v; while the batteries own circuit is dropping .2v so the battery only sees 4.0v.

Have a look at the negative end of the cell, you should see a ring about 5mm up from the end beneath the PVC wrap, the negative end of the cell is a false end with IC components inside. If you don't see this, all bets are off.

It should be easy enough to check for protection, put them in a light and leave it on; when it discharges it will shut off abruptly if it is protected. I have seen these 3.0v reduced cells with and without the voltage protection; either way, they both require ~4.4v to charge.

Again, my comments are based on the fact that your OEM charger is 4.4v as you stated which clearly implies these are not LiFePo4 and do not require a 3.6v charge termination.

Remember that safety is of the utmost importance which is what everyone else is leading to, but given that your cells came with a 4.4v charger....I've explained how and why it works... and ultimately, why your cells wont charge correctly in the wf-139.

Cheers,
Markcm

 

[mdocod]

I have to agree with Markcm on this one.

Everyone in this thread is freaking out way too much, if these are 3.7V cells with 3.0V regulating diodes in them, then there is no increased risk of charging them in the WF-139 other than the fact that the charge rate may be slightly higher than ideal. If anything, charging the cells on the WF-139 could be safer as the actual cell voltage will probably never exceed ~4.05V. I would want to verify this with a DMM and just feel the cells for heat and stuff to make sure nothing weird is happening, but it would probably be fine.

[edit in] but the cells will probably never be "fully" charged in the WF-139.

Even if he did have the LiFeP04 cells that are sold as "3.0V" cells requiring 3.6-3.8V charging, you could charge those in the WF-139 as well. Would they be overcharged and have a reduced cycle life? YES, would it be dangerous? Not really. LiFeP04 can tolerate a lot of abuse. It would probably wear out the cells prematurely but nobody would loose any limbs.