New 2 stage PD lithium Converter charger yet?
When I installed lithium batteries 18 months ago I also changed out my converter charger. I didn't want it constantly charging 14.4 volts. so I returned it and have been using my original PD convert...
Forum Discussion
As I understand it LFP will have a reduced life when held above resting voltage (about 13.4v) for extended periods. The higher the voltage the greater the issue. There is very little additional energy above 13.4 volts to be gained anyway from holding above resting. Maybe 1%
The higher voltages are just for charging. Need zero absorption if going to 14.4-14.6 volts. Charging to 13.8 is common and may need a couple hours absorption. But again no harm to get to only 97%. If that last 3% matters so much the purchased battery should have been larger.
This is all nominal. The real issues actually happen at the cell level. Charging to 14.6 volts will inevitably charge one or more cells over the maximum. The battery makers tolerate this as part of the warranty but it still shortens the life. At the top of charge the cells gain voltage exponentially so it may not seem much at the battery level but individual cells can spike up very fast if not perfectly balanced. Very few battery will hold perfect balance and most are good but not perfect even when assembled.
The higher voltages are just for charging. Need zero absorption if going to 14.4-14.6 volts. Charging to 13.8 is common and may need a couple hours absorption. But again no harm to get to only 97%. If that last 3% matters so much the purchased battery should have been larger.
This is all nominal. The real issues actually happen at the cell level. Charging to 14.6 volts will inevitably charge one or more cells over the maximum. The battery makers tolerate this as part of the warranty but it still shortens the life. At the top of charge the cells gain voltage exponentially so it may not seem much at the battery level but individual cells can spike up very fast if not perfectly balanced. Very few battery will hold perfect balance and most are good but not perfect even when assembled.
