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Hi There,
I have a 100AH Lifepo4 battery with the SmartSolar 100/20 MMPT charger.
The Lifepo4 battery has a charge voltage of 14.6 v and a nominal voltage of 12.8. All the equipment is brand new.
I note the Victron default Lifepo4 setting only charges at 14.2 and 13.5 float.
I'm assuming I can use the expert mode to set this to 14.6v for absorption but not sure what I should use for the float voltage?
Hi @corbijn,
yes you can and should alter the settings in accordance with the specs of your battery manufacturer. For float voltage ask your manufacturer or refer to the data sheet of the battery.
But you most probably wouldn't go wrong if you leave it at 13.5V.
Thanks Stephanie :) I have emailed the manufacturer. Is there any wisdom in using slightly lower than the full 14.6 voltage? Extend battery life etc?
There is a lot of rumours going on regarding lower absorption voltage (and float voltage). Victron for example recommends 14.2V/13.5V. Maybe because of tiny differences in the chemistry or just to be on the safe side. Who knows.
But in my opinion you should go with what the manufacturer suggests.
For LiFePO4 you should keep the cell voltage under 3.6V (and that is if you have a BMS which can turn off the charging if a cell reaches that level (based on monitoring individual cell voltages, not based on battery voltage; without such a BMS, you should use a much lower limit for battery voltage, like 13.8V for a 4 cell battery).
So for a 4 cell battery, this means absolute maximum battery voltage 3,6Vx4=14.4V.
Safer to use a lower value, such as 14.2V.
My thought i use 3.5v x4 = 14v max that is 96% full . If you charge 100% you get less life and it gives you room for safety on bms. You do not need float lithium battery are not like agm or lead . You are miss out on total solar input. Tighten spec 13.5 v float and 13.5v absorption. keep battery at pike voltage
