Lying off-grid with our ship, we use a small generator to charge the batteries during the day in the seasonstart and ending.
In another post it became clear that using a small generator with our MultiPlus II isn’t a combination that works nicely. When having to support a sudden load, the MultiPlus II switches off it’s charger very abruptly, supports the load, and then slowly takes power from the generator again.
The small generator (1.7kWh) doesn’t like such sudden load changes at all, and I allready probably “demolished” a larger generator (4kWh) because of this behaviour.
To circumvent this, I’d like to charge “around” the MultiPlus II built in charger, directly on the batteries. Some of you suggested a charger like a R4875G5 to charge the (LiFePO4) batteries. This way, the generator will be used with less stress of sudden changing loads.
Are there any clever “rules” or “conditions” charging the batteries this way? Or is it just setting the charger to a voltage a bit below the voltage that is in the documentation to be used as the bulk-charge voltage and then just “go”? I guess the generator will then gradually slow down when the batteries are almost full, because the charger will not be able to charge anymore equalling the voltage of the batteries?
Set the ‘charger’ up for correct charging behaviour and matching the inverter bulk/abs voltages to best take care of the batteries.
Do they have comms with the system or are you using a shunt? If the battery havms a range where it balances then that is great.
We have 4 Pylontech US5000 modules, so I guess the voltage can be set between 52.5V and 53V? There’s no real need to balance in this “bulk-charging-proces”? Charging up to somewhere over 80% is quite ok.
No.
The victrons should be set to 52v absorption. Then the pylons raise and lower as they need through dvcc.
Max you should charge with a charger unregulated by dvcc is 52.4V.
80% is closer to 51v. Sort of. It becomes interesting when they are not balanced.
Edited. Depends on battery health. I have a bank at 95% that sits at 50v.