Bob
Well-known member
I've been thinking about charging a lot recently. My 2013 has the option of long life charging to 80%. Is this a good idea? Here's my thoughts.
Charging to 80% is less chemical stress on the battery. That's why Nissan first made the mode.
Charging to 80% is more likely to give you range anxiety because you have...less range.
Charging to 80% looks worse in range statistics. We think that's why Nissan eliminated it.
Charging to 80% takes less time. That last 20% of charge takes much longer.
But charging to 100% includes cell balancing. This means stopping the charge process, measuring each cell, and then draining charge off of the cells that are too high so that they are all at the same state of charge, then finishing the charge. It could also be a smarter algorithm that shuffles charge from one cell to another.
Radio-controlled device fanatics claim that cell balancing is critical for long battery life but I've yet to see data.
Cell balancing gives you the most range, because you aren't limited by the weakest cells. All cells are roughly the same.
Cell balancing may give you longer battery life, because no cell is over-charged or proportionately harder worked. That could be another reason why Nissan might have eliminated 80% charging.
Cell balancing wastes energy because it involves discharging batteries to get them into balance. I have no idea if this is significant but it probably is not wasting very much energy.
Cell balancing also could reduce the life of certain cells because it discharges them during the balancing process.
If you occasionally charge to 100%, you may get the same balancing benefits as always charging to 100%.
Some reading on cell balancing:
http://www.ti.com/lit/an/slyt322/slyt322.pdf" onclick="window.open(this.href);return false;
http://www.mpoweruk.com/balancing.htm" onclick="window.open(this.href);return false;
http://mocha-java.uccs.edu/ECE5720/ECE5720-Notes05.pdf" onclick="window.open(this.href);return false;
What do you think? Is any of this wrong? Am I over-analyzing? Please share your thoughts.
Bob
Charging to 80% is less chemical stress on the battery. That's why Nissan first made the mode.
Charging to 80% is more likely to give you range anxiety because you have...less range.
Charging to 80% looks worse in range statistics. We think that's why Nissan eliminated it.
Charging to 80% takes less time. That last 20% of charge takes much longer.
But charging to 100% includes cell balancing. This means stopping the charge process, measuring each cell, and then draining charge off of the cells that are too high so that they are all at the same state of charge, then finishing the charge. It could also be a smarter algorithm that shuffles charge from one cell to another.
Radio-controlled device fanatics claim that cell balancing is critical for long battery life but I've yet to see data.
Cell balancing gives you the most range, because you aren't limited by the weakest cells. All cells are roughly the same.
Cell balancing may give you longer battery life, because no cell is over-charged or proportionately harder worked. That could be another reason why Nissan might have eliminated 80% charging.
Cell balancing wastes energy because it involves discharging batteries to get them into balance. I have no idea if this is significant but it probably is not wasting very much energy.
Cell balancing also could reduce the life of certain cells because it discharges them during the balancing process.
If you occasionally charge to 100%, you may get the same balancing benefits as always charging to 100%.
Some reading on cell balancing:
http://www.ti.com/lit/an/slyt322/slyt322.pdf" onclick="window.open(this.href);return false;
http://www.mpoweruk.com/balancing.htm" onclick="window.open(this.href);return false;
http://mocha-java.uccs.edu/ECE5720/ECE5720-Notes05.pdf" onclick="window.open(this.href);return false;
What do you think? Is any of this wrong? Am I over-analyzing? Please share your thoughts.
Bob