[brian_]

Not easy because enter a Chevy Bolt in a Vanagon with a shorter wheelbase isn't easy.
But I think it could be quite ''easy'' to enter a complete drivetrain of a regular EV (Bolt, Kona, Leaf, etc) in a FWD van, a pickup or a SUV with decent wheelbase.

Like essentially all current production EVs, these donors have drive units which place the motor (transversely) on are adjacent to the driven axle, so they can possibly go into other vehicles with the engine adjacent to the driven axle. That makes rear-engine vehicles and front-wheel-drive vehicles potentially reasonable targets, but not most pickup trucks. Anything with a driven beam axle at the rear would require a complete suspension replacement.

I think a compact pickup would be an interesting target for a whole-system swap, but it would really be a complete custom vehicle using an EV powertrain, pickup cab, and some other suspension... all on a custom frame.

 

[Yabert]

... but not most pickup trucks. Anything with a driven beam axle at the rear would require a complete suspension replacement.

Personally, I think it's way easier to design and build a rear pickup truck suspension than a complete 360V battery pack with BMS and heating/cooling
Also, there is Honda Rigeline with independent rear suspension and maybe some other pickups.

Anyway, the point is IMHO reuse an intact OEM battery pack help a lot to do an easy conversion.
Chop/weld steel sheet (car frame) is simpler than rebuild a reliable battery pack.

 

[brian_]

Personally, I think it's way easier to design and build a rear pickup truck suspension than a complete 360V battery pack with BMS and heating/cooling

Agreed, but it's not an either/or thing... it's just easier to use a vehicle that is compatible with the drive system.

Also, there is Honda Rigeline with independent rear suspension and maybe some other pickups.

Yes, the Ridgeline has IRS, as do some coupe utilities (but not what North Americans call "pickup trucks")... which is why I said "but not most pickup trucks".

Anyway, the point is IMHO reuse an intact OEM battery pack help a lot to do an easy conversion.
Chop/weld steel sheet (car frame) is simpler than rebuild a reliable battery pack.

Again, a valid point (to some extent, as major structural bodywork is also no joke). And again, a pickup truck would generally need a custom frame, because nearly any modern EV pack (such as the Bolt) is too wide to fit between a pickup truck's frame rails, underneath is too low, and on top would require a really awkward body or box lift... which is why I said that I see a pickup as a "complete custom vehicle using an EV powertrain, pickup cab, and some other suspension... all on a custom frame".

 

[Yabert]

So, a Chevy Bolt need a running A/C system to allow the CCS fast charge. The A/C system could be use to cool the battery temperature.
The DTC condition are:
-A/C Compressor motor voltage sensor circuit low voltage (need to plug the compressor to the 360V batt)
-A/C refrigerant charge low (need to connect the pressure sensors and fill the system with R-1234YF refrigerant)
-Cooling fan relay 1 control circuit (connect the 12V fan)

Well, I don't have the place and the desire to integrate evaporator and condensor for this system and my question is:
Is there any reason that a system with condensor and evaporator bypass/replace by a simple aluminum blocks with holes (represent in blue on pic) couldn't work?
The expension valves for the battery shiller and the cab (not on pic) will be in the system.

 

[jonescg]

I can't quite tell from that picture, but if I recall the Weber Auto YouTube videos correctly, the heat exchanger for the battery is supplied refrigerant from the A/C system after the cabin blower. If you plan on adding A/C to your vehicle you might as well use the cooling power to keep the battery happy.

Otherwise, just running coolant to a radiator out the front will no doubt help, but as you've noted - it won't take a fast charge without more powerful cooling.

I'm actually adding a heat exchanger for chilling the coolant in the battery of the Prelude I'm converting at the moment. I think the A/C system will be the last thing which gets installed, but it should make for a long lived battery.

 

[Yabert]

I can't quite tell from that picture, but if I recall the Weber Auto YouTube videos correctly, the heat exchanger for the battery is supplied refrigerant from the A/C system after the cabin blower. If you plan on adding A/C to your vehicle you might as well use the cooling power to keep the battery happy.

It's exactly how the Bolt system work, but the battery heat exchanger (in center of the pic) is before the cabin. The battery coolant is cool down by the A/C.

My question is more related to an A/C system without condenser and evaporator.

I drive the Van since 6 weeks now without battery coolant and the cells stay closely match (3-4°C difference) at temperature between 20°C-33°C despite it summer here.
If I had the choice, I would not install the A/C system, but the Bolt system claim it in the fast charge initialization.
An heating system is way more important here with around 3/4 of year with temperature below 20°C (20°C to -30°C in fact).

 

[brian_]

Does the Bolt operate the air conditioner as a heat pump, to provide heat with less power consumption than resistance heating? Adding A/C would be a lot of work and a packaging challenge, but it might have the benefit of better heating, as well as properly supporting fast charging.

 

[Yabert]

No heat pump on this Bolt. Simply a separate heater in the battery cooling loop.

 

[Yabert]

Any input about my A/C challenge (post 144)?

 

[MattsAwesomeStuff]

So your goal is to hook up the AC compressor and the electronics, but not either of the radiators (evaporator and condensor), for the sole purpose of fooling the battery charger to turn on?

Presumably, the AC motor/compressor will actually be turning on and off still, and compressing refridgerant, and all that, it just won't go to any rads?

Stating the obvious: If you hooked the entire system up, it would presumably work fine. All you're changing is removing the E and C rads and replacing them with a loop.

And your question is, will that "swap a radiator for a loop" trick work?

...

I only have partial knowledge about this, but, my immediate concern would be that parts of the AC system are going to just about immediately break if they get a liquid when they were expecting a gas. You compress the gas into a liquid which makes it hot, then you cool that hot down to ambient, then you pump the ambient liquid to a second radiator and then let it expand back into a gas that is now cold. That cold gas is what the motor/compressor is expecting, not a liquid.

So, sometimes there's valves and stuff like that to make sure that won't happen, but, I have a hunch they're suitable for normalish circumstances, maybe they won't handle or operate correctly being given a hot liquid rather than a cold gas. Maybe not, maybe it's fine.

When you add your refridgerant, same as on any other AC system, you'll have to pull a vacuum for an hour to get rid of any moisture in the system, because moisture + refridgerant = hydrochloric acid I think. But that's a solveable problem.

I'd be more tempted to electronically fool the system than mechanically fool the system. If it's expecting a voltage, fake the voltage. If it's expecting a sensor, fake the result of the sensor. Should be doable with just some resistors.

 

[Yabert]

Matt, you fully understand my problem and my questions about A/C system.

I'd be more tempted to electronically fool the system than mechanically fool the system. If it's expecting a voltage, fake the voltage. If it's expecting a sensor, fake the result of the sensor. Should be doable with just some resistors.

Really, I would like to do that, but I don't know how to do that.
For me, mechanically fool the system is something I can do, but to electronically fool the system I would need help.

 

[piotrsko]

Should be 3 or so limit switches that have to be on, a high pressure switch that needs to be off, maybe 1 thermistor whatever controls the VCX valve. They sytem might also want to know status of the control relays. Should be an online A/C manual for it showing sensor placement and wiring diagram.

Low pressure prior to compressor, high pressure after compressor, etc.

Im not a A/C guy. All the experts here should know better than me, but I guess not.

 

[Yabert]

I slowly start to think that is possible to electrically fool the system.
Below are the schematic of the system in pdf.

The pressure sensors have those values:
5V - AC low ref : 11.5k
5V -Low pressure: 4.7k
AC low ref - Low pressure: 6.8k
I plan to put 0-10k potentiometers at the place of the pressure sensors and try to change the values.

About the compressor, I don't know how to fake the 360V input so my first idea is to connect the compressor to do a first test at the fast charge station.
If the compressor start I will simply stop the fast charge as my goal is to know if the fast charge work.

 

[piotrsko]

YOUR pdf hints that the variable resistors should work, and you may want to see what the BIG orange gray /orange pair going into the A/C logic board actually do. Looks to me like there is some sort of control happening there that goes to the charger control module on the following page. You may also need to spoof the battery pack temp sensor in the coolant inlet unless the coolant temps go high or low from 20C



My knowledge is limited, BUT, I am fairly sure on the Volts, charging does not require ECM CANBUS monitoring. I know nothing about the Bolts, but knowing how Chevy operates as far as Tech training goes, both systems could be similar.

 

[Yabert]

I tried a fast charge this weekend without success.
I put 10k potentiometers at the A/C pressure sensors place and connect the compressor/coolant pump/radiator fan to the system.
This permitted to clear all the DTC of the hybride powertrain control module, but despite that the car don't allow the fast charge to start.

Any tough?

 

[MattsAwesomeStuff]

Did the compressor start? Was it hooked up?

Hard to say.

Don't suppose you have functioning hardware that you could swap into place and see whether it works or not when connected properly. That would isolate whether the problem is the way that you faked it or whether the charger brains don't work.

 

[Yabert]

Yes, the compressor was conneted. It don't started during the few first attemps of fast charge with the car turn off, but it started once with the car turn on (not sure if it start for car interior or for battery).
The result was the same in each situation: after 30 seconds of precharge (charger side) the car quit/refuse the session and everything stop.

Functioning hardware imply a fully functional A/C system with high pressure in the circuit.
The next step for me is maybe to try the idea of a partial, but pressurized A/C system (describe at post 144).
I don't have other idea...

 

[MattsAwesomeStuff]

Just brainstorming...

Maybe the resistors you used are wrong, or reporting values outside the proper range.

Is the behavior different now (after electronic faking) than it was before? Or did this get you past where you were before, just not as far as you wanted to (i.e. the 30 seconds)? I'm trying to determine if you had zero success or partial success. Zero success to me means check for mistakes or additional things missing. Partial success means tweak what you're able to tweak and try again.

 

[Yabert]

It's probably partial success.
Before the hybrid powertrain module 2 shown DTC linked to the pressure sensor and now report no DTC.
Still, I don't know what to do as I don't know why this Chevy Bolt is not happy at the fastcharge station.

 

[Yabert]

I've tested the van on a small road trip

Everything work well and this powertrain is awesome in the curvy mountain road.
150 kw and 58 kw of regen is
Still no fast charge, so it's a long and ''slow'' roadtrip with bigger days of just over 400 km. But there is a lot (still not enough) of J1772 station at any place and many are free.
More than 10 000 km of done here reaching arizona and we will add 4500 km to go home.
Details here: https://www.thesamba.com/vw/forum/viewtopic.php?t=723737