Chassis welding on an EV

[M4cruiser]

This question suddenly popped into my head, maybe because my old (petrol) car is being MoT'd.

Last year it needed some welding and they had to remove the carpets to avoid the whole thing catching fire.

So that set me thinking ..... in many EVs the main battery is sandwiched into the floor. So to weld it you'd need to remove the main propulsion battery?

That surely makes the job uneconomic? A £300 welding job is now huge.
A 2011 Nissan Leaf / Renault Zoe will surely be reaching this situation soon.

Any thoughts?

[OutInTheShed]

If it needs significant welding it will just go for recycling.

MoT and 'how much welding?' were pretty much the same thing when I was 20 or so.
I'm trying to think when I last had a car welded, I think it was last century, and I've had some crap old cars since then.
Having thought for a moment, I had the exhaust welded on a car about 12 years ago because spares were not available except at 4 figure prices.

[charltjr]

It’s not that big a job to remove the battery on a lot of EVs, drain the coolant, disconnect the cables, a few chunky bolts.

So yes it will add some labour time if it needs to be removed but it shouldn’t be a huge amount.

[ATG]

M4cruiser said:

This question suddenly popped into my head, maybe because my old (petrol) car is being MoT'd.

Last year it needed some welding and they had to remove the carpets to avoid the whole thing catching fire.

So that set me thinking ..... in many EVs the main battery is sandwiched into the floor. So to weld it you'd need to remove the main propulsion battery?

That surely makes the job uneconomic? A £300 welding job is now huge.
A 2011 Nissan Leaf / Renault Zoe will surely be reaching this situation soon.

Any thoughts?

Thought #1: acquaint yourself with how easy it is to drop the battery on a Leaf.

[sjg]

Here’s an old imiev getting some welding: https://youtu.be/kmg0ucfCCyo?si=aVIM3KplG5KgCJLq

As with many EVs, not a big job at all to drop the traction battery out of the way if you have a suitable lift.

[kambites]

As others have said, it's not difficult to drop the battery in most "skateboard" EVs. I think it's pretty rare for modern ICE vehicles to need under-side welding these days anyway, unless they've suffered from significant accident damage. Certainly our 17 year-old Skoda hasn't got any noticeable signs of even surface rust underneath.

[OutInTheShed]

I suspect, if the welding was done to the same standard as in the good old days, you'd be quite lucky if the battery went back in.

[Yodafone]

That is a very good point, image the dodgy garages who quote cheap and not take care and to save time not remove the batteries.

[M4cruiser]

sjg said:

As with many EVs, not a big job at all to drop the traction battery out of the way if you have a suitable lift.

I wonder how many grease-monkey MoT fixing stations (like the one I use) can actually take the battery out of a Nissan Leaf and put the same one back in correctly?

[PetrolHeadInRecovery]

I happened to note a video showing how to drop the E-GMP platform battery a few weeks ago. The link should start the video from the actual removal, in the start you have checks of error codes, removal of covers and ensuring there's no tension in the system.

TL;DW: doesn't look like a showstopper.

[Discombobulate]

No metal chassis to weld on mine (i3).

[tr3a]

Discombobulate said:

No metal chassis to weld on mine (i3).

There certainly is a metal, albeit aluminium chassis underneath the carbon fibre body tub of an i3.

[HTP99]

Is welding a car even a thing now for anything of an age of an early ZOE or Leaf?

[The Wookie]

I would imagine that the battery itself provides a fair amount of protection from the elements and that on most cars it’s pretty well sealed to limit the amount of crud that ends up topside of the battery

Granted welding exposed areas close to the battery might have the possibility for an upsetting outcome!!

Does make one wonder whether the MOT remains fit for purpose, the battery mounts themselves could be considered not far off suspension mounts in terms of safety, I have no idea whether it’s a check item yet.

[Discombobulate]

tr3a said:

There certainly is a metal, albeit aluminium chassis underneath the carbon fibre body tub of an i3.

It does have aluminium bits but none that will need welding. In my lifetime, or the car's anyway.

[98elise]

HTP99 said:

Is welding a car even a thing now for anything of an age of an early ZOE or Leaf?

Agreed. Like others I can't remember the last time I needed a car welding. In my youth it was routine maintenance, as was using plastic padding

[M4cruiser]

HTP99 said:

Is welding a car even a thing now for anything of an age of an early ZOE or Leaf?

In my current experience, Japanese cars need welding after about 15 years.

[tr3a]

M4cruiser said:

In my current experience, Japanese cars need welding after about 15 years.

Rubbish. Japanese cars sold on the European market from the mid-eighties do not rust any worse than European cars.

The Japanese cars that do still rust are used Japanese imports, which aren't as well protected. The reason for this is probably that the Japanese MOT is so much stricter than ours, that few cars are kept beyond their first test, so they don't get into the rusting age on Japanese soil.

[NDNDNDND]

Weird level of magical thinking from the EV-brigade on this thread.

EV batteries take five minutes to replace, and electric cars will never need welding so it's a non-issue.

Apparently.

[Basil Brush]

98elise said:

HTP99 said:

Is welding a car even a thing now for anything of an age of an early ZOE or Leaf?

Agreed. Like others I can't remember the last time I needed a car welding. In my youth it was routine maintenance, as was using plastic padding

The good old days of racks of bacofoil level exhaust systems in Troys and Quickfits etc.