Hello there,
I recently installed in my caravan a brand new IP22 12/30 (1) Blue Smart Charger (replacing a failed 7 year old IP67 12/25 unit).
It charges a 280Ah lithium battery, with similar settings and identical wiring as before - 13.8V absorption, 2hr duration, 13.4V float. Also now with tail current at 2 amps, and bluetooth networked with BMV 700 (with dongle) and 2 x 100/20 Smartsolar chargers, plus charge current set at 25 amps.
The new charger works as expected, except in all contant voltage modes (absorption, float and as power supply) when the charging current has dropped below about 5 amps (at least that is when I noticed it). At this time, a large hysteresis appears. Every minute or so, the charger voltage shoots up above 14V, current surges up to 10 or 20 amps (depending on when you blink), then gradually drops back over about 10 seconds to the set voltage and previous low current. However, overall it does maintain the correct absorption voltage (BMV values), and does eventually switch to float on tail current, and then maintains set float voltage at battery. I see that same behaviour if removed from the bluesmart network. If one did not observe the enormous voltage fluctuations at the charger (on the victron connect app) or the wild jumps in current at the battery (measured on BMV - battery voltage varies only about 0.1 V during a current surge) one would assume all was normal.
This behaviour is just so different from all my other victron chargers (both in the caravan over 10 years and also a full house system over 5 years) that I suspect the new unit is faulty and I do not trust it to work unsupervised!
I would be interested in the experience of others with this very common and highly regarded charger before I contact the seller for a replacement unit.
Many thanks, Leslie
Hello Firegirl,
Welcome to the community.
What kind of load do you have connected to your system?
You say that the voltage on the IP22 side shoots up above 14V, but at the same time, the voltage does not rise at the BMV side, right?
Does the BMV see the current surges?
Hi Igorter,
Thanks for responding.
At the time, the load was a steady 0.3 amps, with intermittent load of 3 amps when fridge cycled on. Yes, the battery voltage is essentially stable (maybe goes up 0.1volts as seen on BMV), while the current surges above 10 amps (as seen both on BMV and concurrently in the Victron connect app of the charger).
I have since removed the charger from the van for testing, and connected it directly to another battery on the bench. No load at all. With the battery at 13.2 volts, and charger set as power supply at 13.3 volts, current limited to 25amp, I see similar behaviour. In the victronconnect app the voltage peaks around 13.8 V, as the current surges over 10 amps, then the voltage drops right down below the set voltage to the battery voltage, and with zero current. It continues cycling like this every few seconds. When the current surges and voltage peaks you can hear the charger making a soft humming sound.
With nothing connected to the charger it holds a steady 13.3 volts, as indeed it should.
Look forward to your thoughts, cheers, Leslie
Leslie Anne Reddacliff
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