Which charger will charge li-ion from 2V ?

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vidramon
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Which charger will charge li-ion from 2V ?

I need to know which charger can charge cells from 2V ?
Sony VTC5 can be discharged to 2V ..
My cells are slightly over 2V, 2.1, 2.2, 2.3V…

Which charger will start to charge them ?

SkyRC Mini B6 refuses to charge this so low kind of discharged cells..

zoulas
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If you don’t mind my asking, why do you want to do this?

thefreeman
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Many charger will, HKJ inform about this in his tests. Manufacturers will often call this ”0 volt activation” and will use a low current when the cell is too low, many integrated charger will also be able to do this (but not with current limiting).

For example : Xtar MC1/MC2 plus.

You can also use a voltage source (a power wall plug, another cell etc..) with an appropriate resistor to limit the current to 100mA for example, until the voltage is high enough to charge in your charger.

But while the datasheet specifies 2V as the minimum voltage, the rated cycle life is given for a 2.5V cut-off and this should be the minimum voltage for normal use. There is practically no energy between 2 and 2.5 V so there is no point in discharging to 2V anyway.

Henk4U2
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Vapcell S4 Plus is quite good, but does not perform a really zero volt activation (leaving light on Facepalm ).

But my “XTAR VC2 Plus MASTER” came through! From almost zero!!
However, the charging current is 0.5A or 1.0A and that’s a bit rich for small cell’s.

So when the cell responded with proof of life, I transferred it to the Vapcell to be charged at 0.2A

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flydiver
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Often a NiXX dumb charger will do just fine.
As has been stated already, you REALLY don’t want to go that low. I personally don’t like to go below 3.0v, 3.2v actually.

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Lightbringer
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Dumb chargers are great for just getting ‘em started. They pick up to 3.whatever almost in seconds. Then stick ‘em on a charger charger which coddles ‘em the rest of the way.

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vidramon
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Thank you all for commenting, I succeed with Xtar VC2 !
Lii 500 also failed in this.

Now I get every cell to 3V and SkyRc Mini B6 can do the rest of the job.
Xtar VC2 also succeed with cells 1.9V, no wonder since they have one of the best chargers in the market.

I do not drain this cells, I got them in this condition, my cells are not drained below 3V..
Now I need to charge them to the max, then discharge to read real capacity and measure internal resistance to see condition of the cells.

NeutralFan
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The Opus BT-C3100 will also charge at very low voltage. I haven’t done that with Li-ion, but with NiMH many times.

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Lightbringer
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NeutralFan wrote:
The Opus BT-C3100 will also charge at very low voltage. I haven’t done that with Li-ion, but with NiMH many times.

Forgot where the cell came from, mightta been one of the mag-ring Sofirns I thought was locked out, but my trusty Ope didn’t touch the cell ‘til I jump-started it with my LK101 for a few seconds.

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clientequator
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2V discharge is very dangerous for lithium cell and can begin to cause physical change in the battery electrode and electrolites. I recommend you be careful with using the battery in the future because it is at larger risk of damage.. the best is to make sure cell voltage do not go below 2.8V.

jon_slider
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vidramon wrote:
I do not drain this cells, I got them in this condition

that sounds extra risky

Prudence would dictate that you take those overdischarged cells to a recycling location, out of an abundance of caution.

usually when a cell gets drawn down below 2.5v it should be recharged immediately. Letting the cell rest for long periods at 2v increases the risk of overheating upon recharge.

otoh, your NMC chemistry is generally considered relatively safe from cell reversal upon overdischarge. Are you feeling lucky?

You ARE breaking safety rules by recharging a cell that was so low. Plus having been at low voltage for some? time increases the risk.

be careful, good luck..

xtarflashlight
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Thanks for your guys’ supports on XTAR chargers. More details about 0V activation function here: