Classic MPPT Tracking Question

[Vic]

Am running the venerable 1849 Firmware on a standard Classic.

Have been trying to EQ several times recently,  and noticed that a single Classic has been toggling Vin between a normal-ish 102 V or so,  down to Vbat + about 5 volts  --  about 67 - 68 V,  and then back to the more reasonable Vin.

Am leaning on this one Classic a bit hard,  asking it to produce 60,  or so Amps out.

FET,  and PCB temps are in the low 50s C range.

Is this situation caused by the Classic managing Thermal inputs?  Is this a vestige of the earlier Tracking patterns?   ...   or   ...

Have there been any improvements in Vin Tracking with later versions of FW?

EQing a battery that needs an EQ can be a bit of a long slog,  so,  the  Classic doing Thermal management does come to mind,  but have seen similar behavior on another system that uses a pair of standard Classics (with 1849 FW),  so,  on those,  so thermal input to the Classics is shared quite well between the two  (this system uses a bit lower Vin of about 93 V @ STC).  Have been running Solar Mode.

The reduced power output when the Vin approaches Vbat is not a great situation,  as it extends the time required to do an EQ from Solar,  and have been running out of sufficient sun to even reach the target Veq ...

Curious,   Thanks,   Vic

[boB]

Vic, I gotta ask...  What MPPT MODE are you using ?

[Vic]

Hi boB,   Solar Mode,  only.  Guess that I should try Legacy P & O?

EDIT:  And,  guess,  by implication,  that you are saying that you feel that this Tracking behavior is NOT related to the Classic trying to moderate its operating temperature.

Are you implying that there have been no significant changes to Solar Mode Tracking in FW versions after 1849?

Have never tried EQing,  using the Honda EU6500is Inverter genset,  as the Honda behaves quite poorly when the SW+ Inverters are in a voltage-regulating mode  --  Absorb and assume the same would apply when Veq target had been attained.  Something about the way that the SW+es regulate voltage,  seems to dump some power back into the output of the genset (which is connected to AC1 in  -- Grid input).   This causes the genset AC voltage to be dragged up in voltage,  to the point that it is above the upper AC input set  Limit.   This disqualifies the genset,  and the SW+es drop the AC in,  and the qualification begins anew,  with re-syncing,  etc.  'Tis an ugly process to watch!

May need to use a large 240 VAC powered DC Charger for EQing ...<<  end edit ...

Thanks,   Vic