Bargain I finally got my MG4 home from the salvage auction

[T1 Terry]

I bought an MG4 repairable write off from a salvage auction in a Melbourne (Victoria Australia) for $10,000 at the fall of the hammer ...... back in August, I finally drove it home today with a few and thrown in ....

The price eventually amounted to $13,400 seems everyone wanted a piece of the action, including the rego mob for a permit to drive it home.

The first exciting bit was having to list the exact route I'd be using to get from the car carriers drop off point to the gates of the workshop yard. It didn't seem to matter to them that it was an electric car, been off the road since April and no idea how much charge was in the battery or where there was a charging station close to the pick up point
First fun part, for some reason, the granny charger is always missing from the car at an auction it seems. Next fun bit, you need your own cable for the AC chargers, that left the only choice available, a DC charger. The first one we found (wife driving as guide and pilot vehicle in the Prius) the DC chargers were never apparently wired up .....
After Google maps took us through streets only the postie knew existed, we found another one, downloaded the required app ... it started charging ... @ 20kW, not the 50kW I was expecting ..... but still charged the 50c/kWh rate the proper fast chargers demand .... too far off the designated route to go searching further, charge for an hr to get enough to get home.

The wife had abandoned me by this stage, so I was back in the hands of Google maps to get me home .... after an hr of road works site seeing and the best traffic congestion Google could find, I arrived at the freeway, a max of 15 mins via the correct route from where I started.

Finally get to drive faster than 15km/h, shitte this thing goes well .... bang, bang, bang from the rear .... the mirrors show the rear bumper flexing out to its breaking point each side, then spring back, and repeat.

After a rather risky assessment, while avoiding B triple trucks and cars all doing better than 100km/h, I find the panel repair place that had performed the damage assessment, had left every supporting piece off and the whole affair was held on by the 4 screws under the hatch .... that was also missing its latch so it wouldn't stay shut ......

But, all that fun aside, and a rather subdued trip the rest of the way home, my bargain poverty pack LFP MG4 drove great, love it .... now to repairing it and getting it cleared for rego

T1 Terry

 

[T1 Terry]

After removing the rear bumper on my salvage MG4, the brace piece behind was also bent .... no big deal, then I saw the corner broken off on the alloy gizmo behind that ..... then I removed the inside cover bits from the boot, the floor is buckled so it will ned too to a body repair shop that can fix that sort of thing and provide specs to show how it was and how it is after repair and how that lines up with the manufacturers specs ....... from looking at the rear of the vehicle in the photos, you'd never guess just how much damage was really done .... it did look like a coat of paint on the bumper, a few bits refitted, and all would be good again .... no idea why they put that alloy box gizmo in the crumple zone that it doesn't look cheap ......

T1 Terry

 

[OriginalBigAl]

That's some energy transfer, it looks like that the main crumple zone is the boot floor, the bumper support has two meaty looking square sections that directly crash energy to that section , which could mean even a minor bump could involve major repairs whilst the outside remains visually sound. Good interesting pics. Looks like the charging unit is liquid cooled? and as you say vulnerable to rear impacts. Back to the massive rubber bumpers of 1980s Volvos ! Good luck and regular updates please.

Edit... could someone move this to T1 Terry other post, on the same subject. [ Moderator: already done. ]

 

[Lovemyev]

As you say, it will need to go on a jig and it will require a decent “pull” first.
It’s tucked under the boot floor and creased it pretty badly.
After the pull, they may opt for unpicking the rear slam panel and then be repaired / replaced.
I notice there is a crease in the rear quarter panel on the drivers side also, hopefully this crease will be come out when the rear is pulled on the jig.
As replacing the quarter(s) involves a fair bit of time and paint work, in order to blend the colour into the rear doors
The body line gaps between the rear door and the rear quarter on the drivers side look to be fairly even though ?.
Do the rear doors open okay without dragging on the catch ?.

 

[Coulomb]

Looks like the charging unit is liquid cooled?

That's usually the case, even with 3.6 kW on-board chargers, and of course these are 6.6 kW or 11 kW.

Presumably the motor and motor controller are in there too. There must be a fair bit of space up front, although possibly a chunk of that may be reserved for the front motor and controller (in the AWD Xpower model). It's a shame that they cover that area with the "no user serviceable parts" black cover. It seems very common these days. "Kein fingerpoken".

 

[T1 Terry]

As you say, it will need to go on a jig and it will require a decent “pull” first.
It’s tucked under the boot floor and creased it pretty badly.
After the pull, they may opt for unpicking the rear slam panel and then be repaired / replaced.
I notice there is a crease in the rear quarter panel on the drivers side also, hopefully this crease will be come out when the rear is pulled on the jig.
As replacing the quarter(s) involves a fair bit of time and paint work, in order to blend the colour into the rear doors
The body line gaps between the rear door and the rear quarter on the drivers side look to be fairly even though ?.
Do the rear doors open okay without dragging on the catch ?.

I think they are just scuff marks where the plastic bumper was trying its hardest to come off the car. All the doors open fine, but there was some water in the rear where a spare tyre well would normally be, probably the rear hatch not having its latch fitted has caused it to flap open while travelling on the car carrier and draw water in when it was raining.

I'm not sure if I should get the folded under bit of the rear hatch panel repaired, or just fit the white one from the other MG4 and get it painted silver to match.

'm hoping the battery charger is the same on the white MG4, otherwise I'll have to strip it out and weld the casing ....... but fit the good one from the other MG4 for the photos that I show the motor transport inspectors

T1 Terry

 

[T1 Terry]

My two charging cables arrived from Amazon today https://www.amazon.com.au/gp/product/B0DBZ1QD1R?ref=ppx_pt2_dt_b_prod_image&th=1
and

https://www.amazon.com.au/gp/product/B0CY4QQD6H?ref=ppx_pt2_dt_b_prod_image&th=1

Nicely packaged, complete with a durable looking bag and the 15 amp unit comes with a genuine "cheater" lead, 10 amp male plug and a 15 amp socket, good heavy cable nd does look truely professional, even if it does break the golden Aust standards

Now, to get this thing straightened out before Christmas, then registered, then I'll look into getting a V2L cable for it and look at the mind bending posts on the open inverter forum regarding making a two way V2L, so when charging stops because the solar has ceased, or a trigger to change from charging to V2L and back can be sorted ......

T1 Terry

 

[MarekD]

After removing the rear bumper on my salvage MG4, the brace piece behind was also bent .... no big deal, then I saw the corner broken off on the alloy gizmo behind that ..... then I removed the inside cover bits from the boot, the floor is buckled so it will ned too to a body repair shop that can fix that sort of thing and provide specs to show how it was and how it is after repair and how that lines up with the manufacturers specs ....... from looking at the rear of the vehicle in the photos, you'd never guess just how much damage was really done .... it did look like a coat of paint on the bumper, a few bits refitted, and all would be good again .... no idea why they put that alloy box gizmo in the crumple zone that it doesn't look cheap ......

T1 Terry

I have an inverter for your car for sale.

 

[T1 Terry]

I have an inverter for your car for sale.

I think that is the charger and DC to DC converter. Contact me via PM with a price please, freight from Poland might make it too expensive

Thank you
T1 Terry

 

[Coulomb]

I think that is the charger and DC to DC converter.

Yes. CCU = Combined Charging Unit. For example, DC output 9-16 V @ 220 A; that's the DC-DC converter spec. 220A @ 13.5V means it can output almost 3 kW!

It can also output AC for V2L, so technically it's an inverter as well. But its primary purpose is charging the traction battery, i.e. it contains the On Board Charger.

 

[T1 Terry]

That part had me confused, the line above clearly say AC/DC and 85vac - 265vac 40 to 65hz, 32 amps
The next line also starts with AC/DC 220 - 490v 22 amps, I'm assuming this is the AC battery charger output, are you saying this unit will work in reverse and that is how they get the V2L output?

If this is the case, what controls the AC voltage output, if it can range between 220v to 490v ..... or is this rms - peak? ...... that doesn't calculate out correctly 220vac =311v peak and peak to peak is a lot high voltage @ 622v ..... if I've got that correct .... no saying I have, all the maths was a long time ago

T1 Terry

 

[haloweenhamster]

That part had me confused, the line above clearly say AC/DC and 85vac - 265vac 40 to 65hz, 32 amps
The next line also starts with AC/DC 220 - 490v 22 amps, I'm assuming this is the AC battery charger output, are you saying this unit will work in reverse and that is how they get the V2L output?

If this is the case, what controls the AC voltage output, if it can range between 220v to 490v ..... or is this rms - peak? ...... that doesn't calculate out correctly 220vac =311v peak and peak to peak is a lot high voltage @ 622v ..... if I've got that correct .... no saying I have, all the maths was a long time ago

T1 Terry

(AC/DC AC in DC out)

AC/DC input connects to the charging port so this is a single phase version by the looks of it

AC/DC output connects to the 400v battery

(DC/DC DC in DC at a different voltage out)

DC/DC input connects to the 400v battery

DC/DC output connects to the 12v battery

When you do V2L there's a resistor that sets the output voltage be it 100v for Japan, 120v for the Americas, 220v for China, 230v for Europe etc
If you buy the wrong one you'll get the wrong voltage, if you make a DIY one make sure you read up on where the resistor goes & what value you need

 

[Coulomb]

That part had me confused, the line above clearly say AC/DC and 85vac - 265vac 40 to 65hz, 32 amps
The next line also starts with AC/DC 220 - 490v 22 amps, I'm assuming this is the AC battery charger output, are you saying this unit will work in reverse and that is how they get the V2L output?

If this is the case, what controls the AC voltage output, if it can range between 220v to 490v ..... or is this rms - peak? ...... that doesn't calculate out correctly 220vac =311v peak and peak to peak is a lot high voltage @ 622v ..... if I've got that correct .... no saying I have, all the maths was a long time ago

T1 Terry

If this is the case, what controls the AC voltage output, if it can range between 220v to 490v

I'm pretty sure that the voltage is set by a suitable CAN command. There is probably another command for the current limit. The voltage and current would almost certainly be RMS values, as is standard for AC.

When you do V2L there's a resistor that sets the output voltage be it 100v for Japan, 120v for the Americas, 220v for China, 230v for Europe etc

My understanding is that the proximity pilot resistance is measured by the EVCC. It interacts with infotainment and when all is well, commands the on board charger into V2L mode.

I didn't think that the resistor affected the output voltage. I thought that you got a fixed voltage, often 220V but it might be 120V in some markets, set by firmware code or a firmware parameter. I suspect that 220V is the usual output for 220-240V countries, because if the battery voltage is at the low end, there might not be enough headroom to generate a 230V waveform without clipping. Even 220V requires some 220 × sqrt(2) + ~12V = 323V. With a 96S traction battery, that's around 3.36 VPC, which is not empty. 230V would need another 14V from the battery, and 240V another 14V again.

But I'm happy to be proven wrong by those that decompile or disassemble the firmware, or by other means.

 

[T1 Terry]

Thank you for the clear explanation, how the V2L worked had me stumped as far as voltage regulation, there are a lot of posts with different voltages and kw outputs, but the limiting factor is the 22 amps, 265VAC @ 22 amps = 5.8kW, but the same 22 amps @ 120VAC = 2600W .... have I understood that part correctly?

T1 Terry

 

[Coulomb]

the limiting factor is the 22 amps, 265VAC @ 22 amps = 5.8kW, but the same 22 amps @ 120VAC = 2600W .... have I understood that part correctly?

I believe that's right, although it's slightly possible that V2L has a different current limit than charging.

 

[T1 Terry]

Missed the post before Coulomb, That means it's not resistor controlled, so maybe restricted to the 220VAC, so around 16.5 amps to get the 3,600W 15 amp power point output. I'm guessing it operates the heat exchanger and pumps as required when in V2L mode .....

T1 Terry

 

[Coulomb]

That means it's not resistor controlled, so maybe restricted to the 220VAC,

I would think that at the CAN bus level, you could ask for any AC voltage within limits, but that's just a guess.

I'm guessing it operates the heat exchanger and pumps as required when in V2L mode .....

At the CAN bus level, I would think that other ECUs control pumps etc. Maybe you can ask a high level ECU to initiate V2L, and it will organise all that. I assume that the infotainment software would do something similar.

 

[haloweenhamster]

Sorry by bad in regards to resistor & voltage
Just googled it and can only find references to current limiting not voltage selecting
I can't find the thread I read before about the voltage output
On MG found reference to 2KΩ limiting to 2.2kW, 470Ω limiting to 7kW

 

[leonkernan]

After removing the rear bumper on my salvage MG4, the brace piece behind was also bent ....

If you want a new crash bar, I just pulled the one off mine today to fit the EV stealth towbar.

 

[T1 Terry]

Sorry by bad in regards to resistor & voltage
Just googled it and can only find references to current limiting not voltage selecting
I can't find the thread I read before about the voltage output
On MG found reference to 2KΩ limiting to 2.2kW, 470Ω limiting to 7kW

The confusion returns If the limit on the AC is 22 amps, then 7kW would require roughly 320VAC. If this is peak voltage, them RMS comes out to around 230VAC which would make sense. The 2.2kW if the peak voltage was 320VAC, would mean only around 7 amps being drawn, well within the current limit .... or have I run off the rails here and I'm on the wrong track?

T1 Terry