Charging without CV or CC on a type 2 EV station?

[Darren2018]

Does anyone know anything about this? I will be making a 72V battery and would like to charge at around 45A, I don't need CV as this will be a range boost setup only and I will be using a programable BMS and coulomb meter with a relay as a safety cut off. I was wondering if you could use the current limiting that's part of the J1772 signal protocol and say a regular 82V+ 45A+ DC converter? I do not mind buying a CC/CV charger but I would like to understand what is actually possible and safe.

I was also wondering if you could you could take the AC waveform and just make it DC with some diodes and capacitors. That along with the current limiting provided by the station would allow you to charge the battery right?

 

[eee291]

I think you misunderstand, there is no current limiting on those stations.
If you give the 16A signal for instance it will activate the solenoid but if you pull more it will disengage and throw an error.
You need a charger connected to those that are within the current they are rated for like <16A, 32A etc.

It's like plugging a diode and caps into the wall and connecting it to a battery.... your circuit braker will pop and/or

Or maybe you were talking about the DC combi? Even then you would need a PWM IIRC to get those to even activate.

 

[john61ct]

At a more basic level

it sounds like you want to just charge in Bulk mode, aka CC-only,

stopping **at** a spec'd termination voltage, which will be higher than where the bank would settle if you were to let it "rest" a few hours isolated.

CV charging aka Absorb is after that setpoint is reached, when you **hold** the charging there, monitoring the falling current amps accepted by the bank, usually until it drops to an "endAmps" setpoint, say 0.01C

which is what is required for a precisely standardized 100% SoC for testing / maintenance protocols, completely unnecessary for routine usage charge cycles.

 

[Darren2018]

I think you misunderstand, there is no current limiting on those stations.
If you give the 16A signal for instance it will activate the solenoid but if you pull more it will disengage and throw an error.
You need a charger connected to those that are within the current they are rated for like <16A, 32A etc.

It's like plugging a diode and caps into the wall and connecting it to a battery.... your circuit braker will pop and/or

Or maybe you were talking about the DC combi? Even then you would need a PWM IIRC to get those to even activate.

Thanks for the info eee291. I was going to get a charger anyway but I was interested to know how they actually work. Could you explain how to get the DC combination station to "activate"?

 

[Darren2018]

At a more basic level

it sounds like you want to just charge in Bulk mode, aka CC-only,

stopping **at** a spec'd termination voltage, which will be higher than where the bank would settle if you were to let it "rest" a few hours isolated.

CV charging aka Absorb is after that setpoint is reached, when you **hold** the charging there, monitoring the falling current amps accepted by the bank, usually until it drops to an "endAmps" setpoint, say 0.01C

which is what is required for a precisely standardized 100% SoC for testing / maintenance protocols, completely unnecessary for routine usage charge cycles.

Yes you are right.

 

[eee291]

Thanks for the info eee291. I was going to get a charger anyway but I was interested to know how they actually work. Could you explain how to get the DC combination station to "activate"?

I'm afraid that is beyond my use case, I only have a motorcycle that uses the on-board charger.
I'm planning on playing a bit with the AC type 2, it's extremely simple compared to the DC combo.
Even then, my on-board charger can only charge at 20A AC and charging on those stations is expensive anyways.
I got them set to 10A right now so I can charge at any household socket which is good enough for a 2.5kwh battery.

This looks like a good start.
http://tesla.o.auroraobjects.eu/Design_Guide_Combined_Charging_System_V3_1_1.pdf