Hallo, I have an LiFePo4 Akku with 12V and 75Ah (4x 3.2V cells with BMS). Wich setting are the right ones. In the App is an option Li-Po. Is this the right one?
Thanks for replies an gest regards
Thomas
asked
Blue Smart 12/17 settings to charge LiFePo4
I changed my lead acid battery with a 12,8V lifePO4 battery.
Most manufacturers of these kind of "drop-in" replacement lithium batteries seem to advise charge settings as follows:
- CCCV load profile
- charge voltage: 14,6V
- cutoff charge voltage: 14,4V
- cutoff discharge voltage: 10V
Victron does not use a Constant Current/Constant Voltage profile:
The default absorption voltage setting is 14,2V.
And the default absorption time setting is 2 hours.
Default float setting: 13,2V (MPPT 75/15) or 13,5V (blue charger 12/15). Why is that difference?
Victron also advises not to discharge the battery under 12,5V! Which is a big difference to the 10V of the lifePO4 prescriptions... Wonder how to set 12,5V on the battery protect they advised...
Victron seems to use a more conservative charging profile? Why is that? To expand the life span? And what is the consequence of using this Victron load profile? Does it increase the charging time? Does it diminish short term useful battery capacity (using less of the capacity by charging under 100% and not discharging so low)?
What's also strange is that the manufacturer of the lifepo4 battery advises a charging current of 10A. Which seems quite conservative in his turn.., because it's a 40Ah battery and I read that a charging current of 0,5C is normal. But here, 20amps seems more like a maximum short term current. Even though the datasheet says that 20A is the max. CONTINUOUS charging current. Why do they use the word continuous then? I almost could not use my blue charger 12/15 because of that, but they allowed sporadic charging with 15A. This will not occur often, because the solar module charges with a lower current, and when I have a lot of time, I will set the blue charger to 4A charging anyway.
I don't seem to get answers on this seemingly confusing and contradictory information. Why is Victron using different charging profiles (not CCCV)? The person of Victron I wrote, almost could not believe that the lifepo4 manufacturer uses a CCCV load profile. So seems to me that there's no consensus or even knowledge of each others methods even though it's the same product? Or are there different types of LifePO4? I did not think so... Just 4 series of some lifepo4 cells of 3,2V?
When I read general information about lifePO4, then the charge profile that victron uses seems better for a long battery life, but the manufacturer of my battery disagrees with that...
I feel your pain about the use of the words 1C Continuous , right after the recommended 0.2-0.5C Constant Current charge profile in all documents.
And the Victron MPPT only allows for a Max charge current, which it pushes all of it (at Max) to the battery during Bulk.
Li-ion might be a good option. It's 14.2V Absorb and 13.5V Float.
Best thing to do is to consult your battery's datasheet and get the correct settings from there. You can then set a custom profile tailored to your specific battery.
