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axolotl98 avatar image
axolotl98 asked

Smart solar 75/15 disconnected from Cerbo

Hello community, first time I post here, as I am faced with the following issue. Any ideas are more than welcome.

1. Setup: System with two (2) Smart solar chargers 75/15 charging each an 80 Ah 12V battery, through 12V in-series 2x20 W and 2x20+1x30 W respectively solar panels . Both chargers are connected through VE direct cable with a Cerbo S-GX

2. Since when: System Setup in Aug 2023 and running remotely and unattended through Victron VRM since then

3. History: I have connected (erroneously) the Cerbo directly to one of the two batteries, the one getting charged by the 70W panels. During December and January the battery was actually depleting it self and the Cerbo was shutting down after 19:00-20:00 every day and waking up the next morning at about 09:00 am. During this time and in the day the relevant charger was remaining in Bulk charging mode, bringing the battery voltage up to about 11.50V and then the battery would die. And this cycle would start again next morning.

4. Issue: Today, I was watching the VRM with the system producing about 40W and about 3.1 Amps and feeling happy that the battery that is feeding the Cerbo would get a good days charge. Suddenly, I see in VRM a production of 50W, the charger moved to Absorption, the battery voltage to 13.5, then 14.5V with the charger to float, then a battery voltage of 2Vs and then the battery voltage kept on fluctuating from 2V to 14.5V with 0W solar production and 0W feeding in the battery. Asked my parents who live nearby to turn over the solar panels for 30 mins in the hope to reset the issue with 0 solar voltage. During this time the solar charger was showing in VRM as Not connected. Actuall first time after last August that this happens. Then, when they turned over the solar panels again, the same data showed on the VRM. 0W solar charge (even though it was early afternoon), 0W battery charge and a fluctuating battery voltage from 10-14.5 Volts. Now its night and the specific solar charger is showing again as Not Connected. Asked my parents to try to connect through Bluetooth to the charger, but this one and only this one is not present in the Victron Connect menu.

5. Question: Is the charger fried? And if yes why? What can I do remotely to try and fix the issue? My parents have access to the solar panels but not to the Cerbo and the solar chargers, as they are located within my covered boat

Thanks a lot for any ideas you may have

cerbo gxchargerconnection issue
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2 Answers
axolotl98 avatar image
axolotl98 answered ·

Seems like the charging side of the Smartsolar does not activate. In between the battery is now completely discharged so even the Cerbo is offline. Would this be able to be addressed with just a hard reset or should the device be send for repair?

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nickdb avatar image
nickdb answered ·

What is the PV voltage at the time? Use victron connect to see the stats.

The MPPT needs battery voltage +6V to start, so maybe you just don't have enough panel voltage to charge the battery.

What are the settings on the chargers?

Start with some data from VC posted as screenshots, then you have a better chance of finding answers.


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