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drumond avatar image
drumond asked

cyrix li ct and charge modes, bulk, absorption, and float

Hello,


I wonder if Cyrix Li Ct reduces the charge current when the Lifepo4 voltage is 13.8V and above. Can it charge in absorption mode and float mode?

I don't have a Quattro nor anything like that (and I can't, don't have enough room anymore).

If the Cyrix Li Ct is not as smart as it should be, what can I do to reduce the amps from the alternator when the Lifepo4 is nearly fully charged?


I have a ve bus BMS but I assume the cyrix li ct opens only when the charge disconnect signal is off (what about the absorption during charging??)

Thank you.

Cyrix Battery Combiner
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2 Answers
Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

The cyrix is just a relay, not a charger.

If you want to limit the charge current you have to use a DCDC charger.

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drumond avatar image
drumond answered ·

Arglll.

I needed a dcdc charger, not a cyrix li ct and a ve.bus bms. Grrrr.

Is there a way to stop the charge from the vehicle alternator automatically with the Cyrix li ct or the ve bus bms when let's say the Lifepo4 is above 13.8V or 13.9V.


If my understanding is right, the picture below will ruin the Lifepo4 in the long run as there is no absorption charging nor float mode..... Why such a diagram in that case???? Isn't there a really important device missing here?


Thank you.




img-20200102-231003.jpg (124.6 KiB)
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Matthias Lange - DE avatar image Matthias Lange - DE ♦ commented ·

A lithium battery don't really need absorption or float.
If the battery is full and the cells are getting to high the BMS will disconnect the cyrix and stop the charging.

If you disconnect the cyrix at 13.8V you won't charge you battery to 100%

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drumond avatar image drumond Matthias Lange - DE ♦ commented ·

Ok thank you.

I have 900W solar panels so I think it is better than the alternator stops charging at around 90% whilst the MPPT takes care of the extra charging.

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