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Fulli avatar image

MPPT 75/15 und LiFePO4-Einstellungen

Hallo,

my English is very bad, so I try in German:

Wenn ich meine halb volle 90Ah-Batterie laden will, fängt der Regler auch mit 8-10A an (Bulk), geht dann aber nach einigen Minuten in Absorption, und nach einer Stunde in Float, wo er nur noch mit 2-3A lädt. Erst ein Neustart bringt ihn wieder in die Bulk-Phase. Ist das normal?

Fulli

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2 Answers
JohnC avatar image

Hallo Fulli. My German is bad too. Just type into 'google translate', then copy/paste to here. Your post comes out as:

If I want to charge my half full 90Ah battery, the regulator also starts with 8-10A (bulk), but then goes into absorption after a few minutes, and after an hour in float, where it only charges with 2-3A. Only a restart brings him back into the bulk phase. Is that normal?

For an answer, yes it's normal if your target Voltages are normal. If your Absorb and Float V's are being maintained then your mppt can do no more. By all means check with a multimeter, but your battery may not be as discharged as you think.


haben Sie einen guten Tag (Have a good day) :)
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Fulli avatar image

Hello JohnC

Thank you for the fast answer!

I took 60Ah from the battery the day before and wanted to recharge it as quickly as possible today. But with Float it takes a long time ....

Here my settings:Volker


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Maybe take another look at your battery specifications and find a better charge profile. Even a manually entered one.

OK! I'll raise the constant voltage to 14.4V and see what happens ...

Maybe try raising your 'Float' to 13.8V. Safer, and should show some Amps. Don't overdo it..

Hi!

Today I have started a new attempt: The absorption voltage of 14.4V is reached much too fast, although the battery is only about half full; how can that be?

Volker

Woher haben sie die Info, dass die Batterie nur halb voll sei?

Wenn die 14,4V sehr schnell erreicht werden, spricht das eher dafür, das die Batterien doch schon voll sind.

Hallo M.Lange,

I have written that I have previously taken 60Ah (from the 90Ah battery). Then I returned about 240Wh, and then started the test.

I connected a Guard II and it showed me 13.1V.

Yesterday I loaded the whole day (+ 300Wh), and had 13,2V in the evening.

I do not quite understand Victron's algorithm:

When the controller starts in the morning, it measures the voltage and determines the duration of the absorption. In my case; Battery >12,6V, so absorption time 6 hours x 1/6 = 1 hour, that's too little, because then he goes into float and charges only with 1-2A. I'll try 9 hours today and will see...

Volker



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