How would you set the charging parameters for LiFePO4 DC-DC charger?

[NBs]

How would you set the charging parameters for LiFePO4 DC-DC charger?

I use on the go being at sea at about 15-20A per hour, and I'm wondering what to set for boost, float and start charging values.

My goal would be max SOC 85% when I drop anchor.

SRNE 50A dc-dc/mppt standard values for Li batteries is boost 14,4V, float -, and 12,2V to start charging.

I have found values here for charging batteries with no load on, or does that affect the values?

The charger has an option to make a user's own charging profile.

Thanks All to you who can help me.

 

[pollenface]

Off the top of my head my choice would be 14.2v, 30mins, float @ 13.4v, 0 temp compensation

Why the goal of 85% when you drop anchor?

 

[NBs]

Off the top of my head my choice would be 14.2v, 30mins, float @ 13.4v, 0 temp compensation

Why the goal of 85% when you drop anchor?

Thank you,

Hi, it may be more than that, because my consumption is about 70-100A per day and the capacity is max 560A, but I don't want to charge to full.

Except sometimes, if I know I need all A. I am sometimes at anchor for several days, I can also charge the batteries with a diesel generator using AC-DC chargers but that's a bit of noise and money, plus a couple of folding solar panels 100W and 135w but that doesn't work often enough (wind/clouds)

 

[mikefitz]

How would you set the charging parameters

The charge voltage with battery loading is no different from charging off load, the current into the battery is just less than with no load.
With a 50 amp charger and load of 15 amps, that's 35 amps into 560 Ah battery. With this very low charge rate by the time the charger hits 'target' boost volts set at anything over 13.65 the battery will be well over 95% SOC. Since you need a charge volts greater than 3.40 per cell for the BMS balance to function , a boost volts of 13.8 or 14.0 is a low stress charge voltage. Set no absorbtion (boost) period and boost recover to 13.35 volts. Set equilisation the same as boost volts but equilisztion period to 10 minutes, ( Set to zero may Introduce faults in the softwere).
Attempting to charge to 85% is not practical, having a charge voltage that allows balancing is needed.

 

[NBs]

Ö

 

[NBs]

Thanks again Mikefitz,

I'll be getting the boat on the water tomorrow and will get to try the system for the first time in a real situation where I can run the diesel.

I think I understood your idea by the way, but did you mean the "no absorbtion (boost)" floating voltage?

My first language is not English, so I'm a bit of a novice here too

 

[mikefitz]

you mean the "no absorbtion (boost)" floating voltag

No, I was discussing the boost duration, this is the absorbtion period where charge voltage is constant at boost 'target' volts. With a low charge current and a large battery this time duration can be zero or a short time, say 30 minutes.
Some SRNE solar chargers get confused if the boost and equalisation durations are set to zero time.

 

[NBs]

No, I was discussing the boost duration, this is the absorbtion period where charge voltage is constant at boost 'target' volts. With a low charge current and a large battery this time duration can be zero or a short time, say 30 minutes.
Some SRNE solar chargers get confused if the boost and equalisation durations are set to zero time.

Ok, thaks