LOW TEMP charging. . .
playing with the Renogy dc-dc charger here -->
Low temperature lithium battery
i added the temp sensor check the charge blocking feature of the charger .
-2.0c outside.
the renogy charger app showed -1.0c and charging blocked.
the Victron app agreed showing -1.0c at the battery terminal,
but the FS Drift showed slightly different. . . 0.3c ( the battery has 3x temp sensors)
so a slight difference in temp readings. . . . .
i warmed up the Renogy charger temp sensor to allow charging,
and the FS happily started drawing 30A. . .
i wasnt so happy about this as it seemed that the internal heater had not kicked in yet - assuming it hadnt seen below 0c yet.
and the battery was taking full charge current so close to the 0c mark (0.3c)
there not mention od the heater in the BMS settings that i can see,
but there is the low temp cut off point (UTP) in the BMS settings . . . so i changed that from 0c to +2.0c (this will allow for the 2degc discrepancy i am seeing across the various temp sensors) - now im happy that the battery wont take full charge current below or near 0c.
that done the trick . . . .
the battery shut off the incoming charge and raised the UTC alarm (Under Temp Charge)
checking this at the Vic` shunt we 49W, around 4A still going into the battery.
even though the charge is OFF, . . . so im assuming this is the power for the Heater id its running?
50W / 4A seems about right?
the Renogy Smart heated needs 4A for the heater.
the Poweroad Heated needs 8A for its heater.
above 0.5c the UTC battery flag cleared. . . and the charger toggle flipped to ON again.
i thought the reset value was 5c? . . . but ill have to recheck that?
looking back the previous screenshots , , ,
we see:
UTP - 0.0c
UTP release - 5.0c
delay - 5sec.
that implys to me that the flag is triggered below 0, and will keep the charge OFF until the temp rises above 5.0c for 5seconds?
so not so sure, will need more testing.?
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looks like i need colder temps to really see the Heater in action.
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