Quote:
Originally Posted by Morlac
One thing that occurs to me is that these lockups are happening when the battery has been completely drained.
If I understand correctly from what others have said about this kind of Lithium ion battery, the smart sensors in the system are supposed to prevent it from actually draining to 0% to avoid the risk of battery failure or explosion on a recharge. Thus, "0 bars" is never the same thing as no-energy, as "0 bars" is calibrated to some % charge remaining.
For that to work, the system would have to shut down completely to avoid any further charge being drained below the 0-bars level.
So what if that step is not working and the battery is being drained below 0-bars? At that point, you might still have the protective mechanism preventing you from initiating the charge cycle. You'd suddenly have a completely unresponsive battery where it had been working fine right up until the failure.
Quoting from Battery University.com
Extreme low voltage must also be prevented. The safety circuit is designed to cut off the current path if the battery is inadvertently discharged below 2.50V/cell. At this voltage, most circuits render the battery unserviceable and a recharge on a regular charger is not possible.
There are several safeguards to prevent excessive discharge. The equipment protects the battery by cutting off when the cell reaches 2.7 to 3.0V/cell. Battery manufacturers ship the batteries with a 40% charge to allow some self-discharge during storage. Advanced batteries contain a wake-up feature in which the protection circuit only starts to draw current after the battery has been activated with a brief charge. This allows prolonged storage.
In spite of these preventive measures, over-discharge does occur. Advanced battery analyzers (Cadex C7000 series) feature a 'boost' function that provides a gentle charge current to activate the safety circuit and re-energize the cells if discharged too deeply. A full charge and analysis follows.
If the cells have dwelled at 1.5V/cell and lower for a few days, however, a recharge should be avoided. Copper shunts may have formed inside the cells, leading a partial or total electrical short. The cell becomes unstable. Charging such a battery would cause excessive heat and safety could not be assured. |
Dear All:
Morlac has a very learned post here. It takes so little time to recharge and I have already said many, many, many times that low power can cause problems. All matter of possible maladies seem to pop up when the battery is low. I still recharge whenever my battery gets a little below 1/2 charge. I have been doing this for a year now on my 6 inch and not a single problem. The battery stays fine and I get no problems at all.
The factory does say in the user manual to try to deplete the battery the first few times. I recommend against that and have said so. I can only go by my own personal experience but recharging when the gauge gets just slightly below half has been great for me. Yes, I am still on the origional battery and yes, it is still working perfectly without a problem ever!