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simonnhardy avatar image
simonnhardy asked

Cerbo GX and Quattro

I asked this question previously .

We have Lifepo4 battery and the boat 12v load is via a smart battery protect. I set this to Li-ion mode but we don’t have a Victron BMS. The inverter is a Quattro 5000. All this is connected to a Cerbo GX and the remote for the SBP has its remote off connected to an REC-ABMS. The problem we have is that if the BMS shuts down the system it also shuts off the SBP. When we start the generator it comes on but the Quattro doesn’t go to charge mode, I am sure this is because the Cerbo GX isn’t powered up because it’s power comes from the boat 12v system which because the SBP has been turned off by the BMS doesn’t restart and thereafter tell the Quattro to resume charging ? Any ideas ?

Update

It was suggested that I power the Cerbo GX direct from the Battery at the Quattro input but this is at odds with the Victron advice found in various places that says.

Never power the GX device directly from the battery as it can keep consuming power after the the battery has reached its low voltage threshold. This will further discharge the battery and can cause damage to the battery.

So the question remains if the Quattro won’t come back to charge mode without the Cerbo GX being powered up, where would I connect the Cerbo GX power supply ?

For now we just turn off the Quattro and then restart, at which point it goes to charge mode and within a few seconds the SBP comes back on as the REC-ABMS tells the remote to switch on and the Cerbo GX powers up and keeps the Quattro running in charge mode.

Once we have solar this probably won’t happen so often but currently we regularly get the BMS shutting down the Quattro and SBP early in the morning so when we get up everything is off so we start the dinosaur squeezing converting machine to restore battery power.


cerbo gx
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3 Answers
Paul B avatar image
Paul B answered ·

You MUST not have a QUATTRO connected through a Battery protect unit as the quattron is a bi drectional unit meaning power is drawn from the batteries when inverting and sent to the batteries when charging, a Battery protect is a no way unit it power from battery to load it cant do both.

Your Rec BMS has a canbus so read up on this and connect it to the cerbo - I Think depending on the model - if so then the quattro should be connected directly to the battery and then the rec sends command through the cerbo to the quattro to stop loads or stop charging but never turns both off at the same time (usually there are exceptions) This is called CCL DCL and DVL control.

the cerbo is then connected directly to the battery as well - with a small voltage sensitive relay that turns it off if the voltage drops below say 10 volts . (8 volts is the total min for a 12v system or 2v on any one cell)




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simonnhardy avatar image simonnhardy commented ·
Hello. The SBP is between the Li and our boat 12v system. The Quattro is connected via a Tyco 500A contactor to our Li bank and this is controlled by the REC-ABMS which, yes, is connected via Can Bus to the Cerbo GX. Currently the Cerbo GX is powere from the boat 12v so if the SBP turns off we loose power to the Cerbo GX and then are in the lockout situation. I hope that helps.
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Trevor Bird avatar image
Trevor Bird answered ·

Hello @simonnhardy . These lithium batteries are pretty good but they come with some real drawbacks don't they? I am guessing the Lithium Batteries do not have their own internal BMS? If they do have their own BMS you could ditch the SBP altogether. Is that an option?

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simonnhardy avatar image simonnhardy commented ·
The Winston Batterys do not have internal BMS but they are significantly less cost than other 600ah Lifepo4 batteries. Victron uses winston cells in there Li batteries ! Our system has an REC-ABMS which is integrated with the Victron System via the Cerbo GX. It has a Csn Bus connection and controls the Quattro via this connection and also has the ability to remotely shut of the SBP.
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Juha Tuomala avatar image Juha Tuomala simonnhardy commented ·
Where do you buy your Winston cells? I'd like to just compare how much cheaper it would become. Using bigger cell-size would save in REC BMS units when the same capacity would be achived. But I guess kWh price varies a lot in different cell-sizes. @simonnhardy
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simonnhardy avatar image
simonnhardy answered ·

We paid circa $2800 for a 600ah pack of 8 cells.

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