[Pandarojo]

One of the things I miss about our beloved Volt, is a faster onboard charger (Lear 3.3kw).
As we know, the Volt shares the charger with some other vehicle, not many, but one of the most interesting is the Coda. This vehicle has two units of our charger (6.6kw) with a configuration master slave at the communications level and in parallel the power output that feeds the battery.
Is it possible to get the electrical diagrams of the Coda to see at the hardware level how the two chargers are connected ?.
Then there would be the problem of intercommunicating the two chargers, but neither do I see it as impossible.

What do you think? Is possible get information about this?

Regards.

----Excuse my poor English---

 

[Barry]

Considering the software changes that would need to be made, and how difficult it is to access that, I don't think it is a practical idea.

 

[Pandarojo]

I was considering building a device that sends the order to start the charge to the second onboard charger, only while the first one was charging to the current indicated by the EVSE, once detected that it no longer loads the power that the evse tells, it to stop the second charger, since the bms will have started the equalization of the cells and we no longer need to load at full power.

No sofware changes are needed in the car for this.

Greetings.

 

[rmay635703]

Remove the 2019 volt charger and install it into an older one

 

[canehdian]

Remove the 2019 volt charger and install it into an older one

This would probably work.
GM likely uses standard signalling/messaging, so as far as your car is concerned it's just sending a message saying "charge please!"
and waits for a message back "done!".
It likely doesn't specify a charge rate every time, that's pre-programmed into the charger unit itself based on max operating parameters (only 120V is limited by computer; 240V always runs at max, charger speaks with EVSE to negotiate rate AFAIK - the vehicle doesn't limit it, EVSE does).
And given electronics typically get smaller as time goes on, it would likely fit in the space the (now ancient) 3.3kW unit occupies.

If anyone is adventurous, order a 2019 part when available, and see what happens

 

[Raymondjram]

I agree with "canehdian". The onboard AC-DC charger is the limiting factor, not the battery. Many past posts identified the higher charging input that the battery receives during brake regeneration. So using a higher rated charger such as replacing the 3.3 kW unit with a 7.2 kW unit will work.

 

[Pandarojo]

Not only that, but when we select the mountain mode, if there is not enough battery for this mode, the load is made at much higher power than with the onboard charger, and when the car regen while braking or in a descent it charges the battery to more than 40kw., so it isn´t a problem for the battery.
As for the issue of the charger, the ideal would be to replace it with another more powerful, but at the level of communication with the car, the easiest is to add another one that works at the same power that is demanded from the original, until the phase starts of equalization of the cells, at that time it would disconnect.

 

[hellsop]

Not only that, but when we select the mountain mode, if there is not enough battery for this mode, the load is made at much higher power than with the onboard charger, and when the car regen while braking or in a descent it charges the battery to more than 40kw., so it isn´t a problem for the battery.

It's not a problem, for 15 minutes, once in a while, or for a few seconds during braking. That's not quite the same as for a couple of hours, potentially a couple of times per day.

 

[Monzsta]

The Coda actually used two Lear 3.3Kw chargers in a parallel configuration. Not a lot of information on the set up.

 

[edk-austin]

Twice the power to the battery means twice the current in the cables and connectors. Not known what the tested limits are in 2010-2018. And since we know that the OBCM is already about 95% efficient in gen 2, going to twice the power could result in twice the thermal dissipation in the OBCM area. Is thermal management up to the task? AFAIK (search the old FB posts), thermal control was stated as the reason 2016 did Not have 32A charging.

 

[Pandarojo]

Twice the power to the battery means twice the current in the cables and connectors. Not known what the tested limits are in 2010-2018. And since we know that the OBCM is already about 95% efficient in gen 2, going to twice the power could result in twice the thermal dissipation in the OBCM area. Is thermal management up to the task? AFAIK (search the old FB posts), thermal control was stated as the reason 2016 did Not have 32A charging.

The limits of the OBCM would not be modified, since each of them would supply the power for which they are designed, being connected in parallel, the supplied current is doubled, may be a diode were required in each one of them to avoid problems with reverse current. The battery would not be affected either because even at 32A it is very far from the maximum current limits.
On the other hand, the connectors are also designed for 32A, and in its case, it would already be the EVSE that will limit the current to the limits for which it is designed.

 

[canehdian]

Is thermal management up to the task? AFAIK (search the old FB posts), thermal control was stated as the reason 2016 did Not have 32A charging.

The unit is liquid cooled, is it not? If so, there's definitely room for enhancements (if required) and they don't need to be in the OBCM area, just anywhere along the coolant line (higher speed pump, larger chiller unit, etc)
But I suspect that reason was just BS, and like everything else on the volt, the cooling unit is well over-sized for the task.
If this is potentially an issue, it's likely only a problem for those in the most extreme of climes, the rest of the continent would never have a problem. Much like overheating engines - the rad is spec'd for the worst possible scenario - most people never drive in ambient that high, ever, and even a severely malfunctioning rad (e.g. huge amount of damaged fins) is capable of supplying enough cooling potential that they'd never know there's a problem.

 

[Paulacton84]

O.. the Coda. This vehicle has two units of our charger (6.6kw) ..
Is it possible to get the electrical diagrams of the Coda to see at the hardware level how the two chargers are connected ?.
Then there would be the problem of intercommunicating the two chargers, but neither do I see it as impossible.
....---

thats the hard way to go from 4 hours of charging to 2 1/2 or so, instead, just get 4 heavy duty chemical drums, and mount them in your garage floor on bearings, and run 2 of them with 10 horsepower compressor motors, Drive the car into your garage, turn it on, set it in low, chock the rear wheels and run your dynomometer... that way you can use the built in regenerative braking to fully charge in 20 minutes or so, just like driving down pikes peak....

or, you can just drive it and not worry, the built in generator is more efficient than most power power plant/ power grid/distribution grid systems, so you not giving up anything enviromental, just drive the car the way it was designed to be driven:
Plug it in when you can, drive it when and wherever you wish, with no worries about charging...

 

[Kuikka]

Has anyone attempted to charge the battery directly? Either through the original BMS or bypassing it. Adding additional chargers would be super easy if the car adjusted to the additional energy. Anyone brave enough to test it?

 

[PCRover]

It wouldn't surprise me if GM makes the 2019 charger "different" so you can't just pop it into the current model. If they don't do that there might be a run on 2019 chargers when they become available.

 

[Steverino]

It wouldn't surprise me if GM makes the 2019 charger "different" so you can't just pop it into the current model. If they don't do that there might be a run on 2019 chargers when they become available.

You are thinking GM would take the time and engineering effort to make it different just to stop a few people from ordering these $1000 units?

Is that the reason you can't order the 2016, 2017, or 2018 unit? Because there is a huge rush of people buying it to retrofit into a Gen 1 Volt?


If GM makes the part different, it's because the change is needed, not to stop people from buying it.

 

[Pandarojo]

After looking for information on the web about how to increase the charging capacity of our Volt, I have found that this has already been done in the Nissan Leaf. It is exactly the same as what I was looking for.

Anyway, I think the best way to do it would be as follows:

1.- Change the charge port for one of type 2, also called Mennekes, which handles 3 phases and neutral.
2.- Add two chargers of type BRUSA NLG513 or similar, and make a star configuration, each one of the 3 phases and the neutral to each charger.
3.- The output of each charger should be connected in parallel to the battery, for which it would be necessary to see if the cable section and connectors of the charging circuit is sufficient, about 9kw on the DC side at 360V is about 25 amps. I think so, but we should be sure.
4.- Make the control circuit for the two auxiliary chargers, so that they supply the same power as the original one, when the original one is supplying the power that is required. When you supply less power than the EVSE indicates, it means that the car has started the equalization stage and we will disconnect the auxiliary chargers.

In this way the wiring on the AC side will supply power in a suitable way without overloading the cable or the connectors.

Changing the charging port can be a headache, but I'm just making the statement of how the improvement of the car's charging capacity could be made. You could also leave the current charge port and add a new one in another site, such as under the license plate. In this way, one charging port or another could be used interchangeably, depending on our interest.

Surely many things escape me, all suggestions are welcome.

Regards.

 

[nedfunnell]

Hey all,
I am interested in doing this as well. I am getting my Volt next week (a 2012) and I think I would benefit from having better charging speed. I often need to make 200+ mile trips, but with a number of stops along the way. Being able to add twice the energy would be neat, and I'm interested in trying it out, even if it never pays for itself.

Check out this old thread where I brought up the idea of a second charger: https://gm-volt.com/forum/showthrea...OEM-charger-for-6-6kW-charging-CANBUS-hacking
I lay out a possible strategy for adding a second charger there, building on the work of an engineer that made a Lear charger (from a Spark, but identical to a Volt charger) work for his custom pack. I still think it could be done. No real useful discussion there, unfortunately, just the same old "It can't be done", "You might hurt the battery" and "Just drive the car".

Interesting to know the the CODA has the same arrangement I'm interested in. Too bad none of that hardware is available to check out.

Pandarojo- I think the Brusa route is possible for you, just more expensive than I am willing to take. Also, 3-phase supply is not readily available in the US, at least not to EV drivers. Good luck, though, if you go that route!

 

[dznf0g]

It's not a problem, for 15 minutes, once in a while, or for a few seconds during braking. That's not quite the same as for a couple of hours, potentially a couple of times per day.

Exactly!!!!

 

[srmarti]

You are thinking GM would take the time and engineering effort to make it different just to stop a few people from ordering these $1000 units?

Is that the reason you can't order the 2016, 2017, or 2018 unit? Because there is a huge rush of people buying it to retrofit into a Gen 1 Volt?


If GM makes the part different, it's because the change is needed, not to stop people from buying it.

The Gen 2 charger is located in a different place and likely not bolt-in compatible. Most would probably think going from 3.3 kw to 3.8 kw isn't worth the effort. Maybe if you could double the charge rate...