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From the following Youtube video (at 3:15min) I got that it is dangerous to recharge a Lipo/Li-Ion-Battery after it was completely discharged (0V), because it will catch fire.

https://youtu.be/1rg3ZWxBNUE?t=194

I'm using the following circuit. It cuts off the load at 2,5V, but then there is still the self discharge, which leads the voltage down to 0V volts by the time:

enter image description here

Is there a common or established way to prevent recharging a completely discharged battery, which is fitting to the circuit from above?

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  • \$\begingroup\$ What do you mean by "completely discharged"? 0V or ~2.5V? \$\endgroup\$
    – Adi
    Commented Jan 5, 2021 at 16:42
  • \$\begingroup\$ 0V, like it was meant in the link I've posted. 2.5V is not dangerous, but 0V is, if I got it correct. \$\endgroup\$
    – playmobox
    Commented Jan 5, 2021 at 17:12

2 Answers 2

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When a lithium-ion battery is overcharged, copper from the anode current collecter can become dissolved and move through the cell shorting or providing a low impedance path from anode to cathode.

If you were try to charge a battery in that condition with the normal charge current, the battery would likely overheat and enter thermal runaway.

The condition is somewhat reversible, but the charger has to be able to sense and recognize it, and enter a low-current precharge phase until the copper is re-deposited on the anode's current collector, and the cell voltage rises to a point where it's safe to increase the charge current.

Of course there will be some permanent degradation of the cell at that point.

Some systems support that type of feature, but if they do not, as in the case of yours due to your protector, they will just refuse to charge the cell. (Which is probably the safest way to go.)

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  • \$\begingroup\$ So with 0V in the battery the charge-current would not pass a certain threshold which would trigger the charging process, in this circuit at least. Repeating it just for safety reasons. Please correct me if I'm wrong. \$\endgroup\$
    – playmobox
    Commented Jan 5, 2021 at 18:07
  • \$\begingroup\$ Your DW01A pack protector has a min overdischarge protection voltage of 2.3V. If the battery is below 2.3V, it should not allow the charger to charge the cell. \$\endgroup\$
    – John D
    Commented Jan 5, 2021 at 19:06
  • \$\begingroup\$ Ok, so far so good. I've found the battery protection IC XB8089D link featuring a "0V Battery Charging"- Function. Does this mean, that this IC is able to recharge a 0V-Battery without it to catch fire? \$\endgroup\$
    – playmobox
    Commented Jan 5, 2021 at 19:33
  • \$\begingroup\$ "Note (1) Some battery providers do not recommend charging of completely discharged batteries. Please refer to battery providers before the selection of 0 V battery charging function." \$\endgroup\$
    – Bruce Abbott
    Commented Jan 5, 2021 at 19:44
  • \$\begingroup\$ @BruceAbbott is correct, Li-Ion batteries can be dangerous and it's important to follow all of the manufacturer's recommendations for the cell, regardless of what the charger and protector are capable of. \$\endgroup\$
    – John D
    Commented Jan 5, 2021 at 21:07
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The DW01A IC used in that circuit has overdischarge protection, so unless the battery is drained without the circuitry, you should be fine.

It should disconnect the battery cell when it detects voltage falling below threshold.

Soruce: HGSEMI datasheet

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  • \$\begingroup\$ Doesn't OP have a un-rechargeable battery then? If the current battery voltage is 0, the under-voltage protection kicks in and the charger never charges the battery? \$\endgroup\$
    – Adi
    Commented Jan 5, 2021 at 17:25
  • \$\begingroup\$ right, but afterwards there remains the normal self discharge process of a battery, or not? And I would like to know if there is a way to prevent a fully discharged battery (0V) from recharging again, because it will get hot, start to smoke and then catch fire. How to stop the possibility to recharge, after it felt - let's say - below 2,3V by the self discharge process? \$\endgroup\$
    – playmobox
    Commented Jan 5, 2021 at 17:27
  • \$\begingroup\$ @AdityaChavan I thought the undervoltage protection is just cutting of the load from the battery, so no further discharge is possible by the load? \$\endgroup\$
    – playmobox
    Commented Jan 5, 2021 at 17:29
  • \$\begingroup\$ Yes, the undervoltage protection disconnects the battery ground from the rest of the circuits ground. This includes the charger, thus you end up with a un-chargeable battery. I thought the question meant how you bring back a completely discharged battery, which is still possible but difficult without making a new circuit. \$\endgroup\$
    – Adi
    Commented Jan 5, 2021 at 17:38
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    \$\begingroup\$ There are procedures for bringing back deeply discharged batteries, like low current over the course of days or using pulses. DW01A will automatically reconnect the battery if it detects charging. \$\endgroup\$
    – crossroad
    Commented Jan 5, 2021 at 18:17

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