Victron Quattro and 100-50 smart solar disagree

oldbargee

Hi, I have a 5kw Victron Quattro that on it's own works fine in charging our 600Ah wet cell traction battery set when connected to the mains electric. ie it starts at bulk, then runs through absorbtion and onto float. However when I installed some new PV panels and a 100-50 smart solar controller, the smart solar stays on bulk and I can hear the batteries bubbling. This was starting with charged batteries and the settings for the batteries on the two units are the same. As the batteries do not get overcharged just using the quattro I am assuming they are in OK condition.

I wired it up as per the victron wiring diagram although last year I had the panels wired into the solar socket on the quattro after the MPPT. That worked fine although I don't know if the quattro was regulating a regulated supply (if you see what I mean) I also don't know how much current the quattro can take through that socket.

Anyone any ideas?

Dave Angelini

Pictures?  Also is this system networked mppt to inv/charger? Since you have mains AC charging what is the purpose here? Confusing!

oldbargee

Sorry  not to be clear. I have a Victron quattro that is a 5kw charger invertor. It runs our domestic system on our canal  barge. The solar panels keep the batteries charged when we are not connected to the mains and presumably help cut demand to the mains when we are.

To keep the story simple all was well when I fed the MPPT output into the solar socket on our quattro but now that it is fed onto the bus bars as per victron circuit diagram it continues to run at bulk charge even with fully charged batteries thus boiling the batteries.

Dave Angelini

OK, so why is the mppt stuck in bulk? Is it a victron also? Are the charge settings configured correctly?

There is a condition when using 2 chargers that are not networked, your mains and the mppt, the one with the lower set-point V will go to full output and the other will fight it. Sometimes this can be very desireable to minimize grid or gen fuel.  Sometimes it is not desirable.

Not sure if that is your problem, and they both would have to be on to do what I described.

Marc Kurth

I can only think of two reasons that a charge controller is stuck in Bulk: The setpoints are high or it is defective.

The transition from Bulk to Absorb is not a "changeover" like a relay or switch. Bulk is simply the portion of the charge cycle before it is able to reach its Absorb setpoint - because the battery load exceeds its capacity.

Once the battery reaches a certain charge level, the charge controller is able to reach its voltage setpoint - it is then in the Absorb phase.

Dave Angelini

Hey Marc, Played alot of ZZ top this last weekend. Hopelessly stuck now on Bon Scott and the 1973 to 76 era when guitars first hooked me. My young relatives keep trying to find me "new" music,  there is so little new good rock and roll these days. Just smiling how lucky I was to 18 ish back then.

There is one more way that a controller besides the usual can be stuck in bulk. It is when there are multiple chargers and they are not networked or set close enough. The lower set point charger does the normal 3 step, the higher set B V controller never gets to the  B set-point and stays there. If it is high enough, it is a way to overcharge a battery and alot worse. Had a system do this after a hurricane. Damaged from lightning, and the owner could not get there for a week. I know this is the defective case like you sited but it could also happen if not configured correctly.

On the other hand, it is a great way to set up a genset with solar. The lower setpoint generator just idles when the clouds clear and the solar does the work. Saves fuel and charges no matter what the clouds do.

littleharbor2

Could there be a high resistance, bad connection between one of the cc's and the battery causing the cc to think voltage is lower than it is?

Dave Angelini

Anything is possible and the OP never came back...... Usually bad wiring, resistance causes a drop in voltage. If it was networked probably not an issue. In this case I doubt there is a network with the gen and solar. Without the network the other controller would not know anything except its own reading.

Are you south of the border? What is it like on the baja? Pretty normal I bet!