question

syorigami avatar image
syorigami asked

Temperature Compensation Value Mistmatch

Hello,

I'm asking for the solar assembly of my friend on the neighboring boat in the marina.

The installation of the system is as in the attached image. TEMPERATURE COMPENSATION for FLOAT CHARGING VOLTAGE (13.6V - 13.8V) is specified as -3mV/℃/Cell in the datasheet of RITAR brand service batteries included in this setup. The same parameter is specified as -4mV/℃/Cell for CYCLE USE VOLTAGE (14.2V - 14.4V). The same document also gives a value of 6 for CELLS PER UNIT.

VICTRON CONNECT installed on the mobile phone shows TEMPERATURE COMPENSATION as -16.2mV/℃. And it's like this field is not modifiable.

Does this difference between the value shown on the VICTRON CONNECT and the value indicated on the battery datasheet adversely affect the performance of the system? What should be done to correct the negative effects?

Another question is; Which Victron product would you recommend to charge this service bank consisting of 2 RITAR batteries from shore power?

Thank you in advance for the replies and comments.

ing-electrical.png


battery chargingVictronConnectshorepower
ing-electrical.png (104.3 KiB)
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1 Answer
Mike Dorsett avatar image
Mike Dorsett answered ·

The Victron temperature compensation can only be adjusted using "custom Battery" type setting. Your friend's use is cycle - daily discharge, so the -4mV/c per cell applies, giving -24mV per degree for 6 cell. With the default of -16mv, this would be 8mV per degree over 25C. So the degradation is really temperature dependent. Given that the Float compensation is only 3mV/C/cell - or 18mV per C, I would not worry about this difference as long as temperatures are below 30C, and above 20C.

The charger question depends on the daily energy use, or if only occasionally used...

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