Chargery BMS to control charger on COM1 port.

[Heyjimmy911]

I bought a chargery BMS and need a little help integrating it to my golf cart. The bms has the ability to send a signal to the charger to reduce current as individual cells approach the high voltage discharge. The challenge (for me) is interpreting the technical information between the BMS people and the charger people.

According to chargery "on COM1 port, The BMS send high (3.3v) or Low (0v) level to control charge current, High means the charge current need go down."

Question 1: When a BMS send the "high" signal at 3.3v, what does this mean to the charger? Move from bulk absorb? Absrob to float? Some other type of current management?

According to chargery: "if connect other (non chargery) charger to com1 on BMS, it must be isolated with BMS, the bms send high voltage 3.3V to the diode of photocoupler, the current is under 5 mA, the photocoupler must be added to the charger. the diagram is attached."

Question 2: can anybody recommend a photocoupler that meets the requirements in the diagram
Question 3: how would you power the photocoupler? 12 v external power?
Question 4: what is the power/signal coming out of the photocoupler? Is it an open/closed circuit or is it 0 / 3.3v coming out of the optocoupler?

Thanks!



System (Golf Cart):
Charger - Elcon TCCH-48-25 Currently being re-programmed.
Charge profile: Victron default Lifepo4. Absorption voltage 56.8v, Float 54.0, Equalization Disabled,Re-bulk voltage offset .40v. Absorption duration Fixed. Absorption time 2h. Tail Current Disabled. Voltage Temp compensation Disabled.
Panels: 2 sunpower 327W
MPPT: Victron Smart Solar 150/35
Batteries: 16 272AH Lishen
BMS: BMS16T-300 300A DCC for discharge,and 100A DCC for charge
Why chargery: Less expensive than my REC BMS system. I can let you all know if all the bugs have been worked out. I really hope it all works.

 

[Bob B]

I think you are breaking new ground .... did they tell you it would work with the non-chargery stuff?

 

[Heyjimmy911]

I think you are breaking new ground .... did they tell you it would work with the non-chargery stuff?

I think so, the quotes above are from Jason, but only with the isolation of the photo-coupler. The person re-programming the Elcon charger indicated his charger can be triggered to change an action either by a voltage or by a circuit opening or closing. He can make that action whatever I want.

So, what would the best action be for a charger which is informed a few of the cells are approaching the charge limit? I imagine the best action for would be to reduce the total current to the point that the balancing action of the BMS can be effective at bleeding current off the high cells, until the rest of the cells catch up.

On my other system, the REC BMS throttles the charging watts my Victron Quattro puts out and perfectly balances all the cells. I just don't know what it's actually doing to make that happen. On the REC system, they already had an integration to the Victron GX but it really gets pricey by the time you buy all the needed pieces and parts.

If the Chargery can't control the charger, it's not the end of the world. I think if it could be figured out, the people on this forum would be the ones to do it. This forum is such an amazing resource.