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fimig asked

Can a buck boost DC/DC converter be connected to and managed by a Cerbo GX via CAN-Bus?

cerbo gxOrion DC-DC Converters not smart
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basm answered ·

Did you ever find out how to connect these?

I have a DC-DC TS-800 (50A) convertor and looking for the right way to prevent the buck-booster from overcharging the LifePO4 Battery Pack. The BMS communicates through VE.Can to the Cerbo. No idea how to connect the DC-DC convertor to the Cerbo. Any tips are appreciated.

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nebulight avatar image nebulight commented ·

From what I see in the TSConfig software, the CAN bus only looks to be configured for a temp sensor.

As for turning off the buck boost, does your BMS have any relays or optocouplers? You could configure on/off with the purple wire with option 50 in the software. Then take an ignition signal from your vehicle and run it through your allow to charge relay on your BMS then to the purple wire. This way it would only ever be on when the vehicle is running, but the BMS relay could open the circuit turning off the buck/boost.

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basm avatar image basm nebulight commented ·
Thanks for the quick response. I'm running a REC Active BMS with optocouplers and relays so voltage wise I think that might be the solution to prevent overcharging.


Doesn't account for preventing low temperature charging though (other than buying the imho ridiculous expensive CAN bus enabled temperature sensor for the booster).


I just wrote REC a mail to ask if the Charging Optocouplers also use the low temperature thresholds set in the BMS or only the max voltage settings. Let's see.


Otherwise since two weeks (15 december) Cerbo firmware (beta/release candidates) supports switching relay 1 based upon a temperature sensor. I thought of daisy chaining the BMS voltage based charge optocoupler with the temperature based relay1 of the cerbo to combine these in series to set a high signal on pin2. If either the charge opto coupler or the temperature threshold relais disconnect, pin2 ends up floating or low and the convertor should not charge.


Kind regards,


Bas



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