I am using a Victron 150/35 charge controller to charge a 48v Chevy Volt battery. I was told I should turn float and equalization off and let BMS on the Volt battery handle the rest. I am unfortunately not able to find an option to turn float off. My current settings are attached.
But with those settings it's as if float still turns back on.
FYI - I have a Chevy Volt setup also (32 KW) and use the 250/100 controller, same config. as yours. Been running the past year with similar settings as was suggested, Absorption and Float being the same value, in my case 48.6 (cell 4.05) I noticed early on that the pack needs a "push" to reach 48.6 when the values are the same so I ended up setting my Absorption to 48.7 (cell 4.06) and kept the Float at 48.6. Overall very happy and wish I could find more but it seems like the price for these batteries have skyrocketed since I purchased mine. I assume others have discovered them as an alternative.
Note - The one main difference is that I noticed is your screen has the Absorption time of 6 hrs. I believe that is not needed, I have mine set to 1 hr. per a Victron setup: https://www.victronenergy.com/live/victronconnect:mppt-solarchargers
That's great information, thank you! I've also noticed Chevy Volt batteries getting more expensive.
There isn't an option to disable the Float stage.
However, you can simply set the Float Voltage as low as it will go which will have the same effect.
Thanks WKirby. I have float set as low as it will go (36v), but it still periodically says the battery state is float. Just to confirm, are you saying it's not doing anything when it says state: float?
Hi @Jonathan Bishop,
To be sure: do you want the charger to stop charging totally when float state is reached, or do you want the voltage to remain constant? if the latter: set float voltage the same as absorbtion and it will try to keep the voltage at the same level.
You mention a BMS, what BMS are you using?
Hey Daniel, my understanding (which may be wrong) is that it is better for lithium to stop charging and on another site I was told to make sure float was turned off. I have a Xioaxiang BMS which does ha e the ability to turn off charging port when it reaches a full charge.
A li-ion that can be charged to 4.2 volt, can be held at 4 volts for a long time without damage.
It depends on the use of the system what is best, but with solar charging, I'd set float voltage to the same level as absorbtion.
If you would use LiFe(Y)PO4, then settings would be different, depending on BMS characteristics.
