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Over the years, I've seen lots of negative comments towards BEV's without active battery thermal management, mentioning battery degradation, Rapidgate, and other issues.
It's all over Youtube, car reviewers and self-proclaimed experts are actively feeding this argument.

Yet now that the cars with active TMS are aging, they are showcasing LOTS OF ISSUES.
One of the biggest risk is liquid coolant leaking inside the HV battery pack, potentially damaging the batteries but also posing a risk for shorts and fires.

Another issue is that thermal management consumes energy, sometimes lots of it.
In some cases where the battery is purposely heated to decrease internal resistance it may contribute to battery degradation rather than prevent it.

Active thermal management increases production costs (significantly), maintenance costs, operation costs and also battery replacement costs. These systems also add weight.
Yet, cars with such systems are seeing their HV batteries degrade at similar or sometimes higher rates compared to systems with passive cooling.

So in my opinion, while thermal management may be a necessity in the luxury segment where owners can stomach the costs of such a system, I think that it does not belong in the more economical segments, below say £30k.


Thread on Ampera coolant issue Minor coolant issue :D

Video of Bjorn with his early Model S having issues:

Video of a Model X leaking coolant :

A video about the Chevy Bolt HV battery disassembly will help you realise how complex and massive these systems are:
 

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So in my opinion, while thermal management may be a necessity in the luxury segment where owners can stomach the costs of such a system, I think that it does not belong in the more economical segments, below say £30k.
Yep.

Fine if you don’t want rapid charging over 40 kW and your battery size is under 40 kWh. :)
 

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Leaf e+ 62kwh https://share.octopus.energy/quiet-puma-274
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Over the years, I've seen lots of negative comments towards BEV's without active battery thermal management, mentioning battery degradation, Rapidgate, and other issues.
It's all over Youtube, car reviewers and self-proclaimed experts are actively feeding this argument.

Yet now that the cars with active TMS are aging, they are showcasing LOTS OF ISSUES.
One of the biggest risk is liquid coolant leaking inside the HV battery pack, potentially damaging the batteries but also posing a risk for shorts and fires.

Another issue is that thermal management consumes energy, sometimes lots of it.
In some cases where the battery is purposely heated to decrease internal resistance it may contribute to battery degradation rather than prevent it.

Active thermal management increases production costs (significantly), maintenance costs, operation costs and also battery replacement costs. These systems also add weight.
Yet, cars with such systems are seeing their HV batteries degrade at similar or sometimes higher rates compared to systems with passive cooling.

So in my opinion, while thermal management may be a necessity in the luxury segment where owners can stomach the costs of such a system, I think that it does not belong in the more economical segments, below say £30k.


Thread on Ampera coolant issue Minor coolant issue :D

Video of Bjorn with his early Model S having issues:

Video of a Model X leaking coolant :

A video about the Chevy Bolt HV battery disassembly will help you realise how complex and massive these systems are:
All depends on usage pattern.. For me the lack of full thermal management was a plus, with around 200 miles range I'm hardly ever going to need a rapid charge..
Looking at how much power the id3 was reported to be using to heat the battery in winter I'm happy my Leaf e+ hasn't got full thermal management, less to go wrong, less power hungry on short trips & easier to replace, repair or upgrade battery in future as Cleevley are now doing with older Leafs..
Of course this is subject to how the vehicle is used, if long trips & rapid charging is a high priority then thermal management is a must really.
Horses for courses as they say ...
 

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Ioniq 28kWh has simple air cooling, rapid charging of 60kWh, 2x capacity, and efficiency of 5m/kWh, so I am not currently changing. It will do 3x90 mile recharges for a 320 mile drive quite happily. No degradation in range after 3 years/ 32,000 miles.
 

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Leaf e+ 62kwh https://share.octopus.energy/quiet-puma-274
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Ioniq 28kWh has simple air cooling, rapid charging of 60kWh, 2x capacity, and efficiency of 5m/kWh, so I am not currently changing. It will do 3x90 mile recharges for a 320 mile drive quite happily. No degradation in range after 3 years/ 32,000 miles.
I had the 1st ioniq & it was one of the best cars I've owned but soon found out that lack of reliable rapid chargers was a bit of a gamble on my occasional longer journey ( it was a few yrs ago & things have much improved now ) I realised that my longest journey of over 300 miles would require just 1 rapid charge in the e+ which would be at around the same time as I needed to take a break anyway & no problem for a passively cooled battery..
Apparently the e+ can do just over 70kW charge on the right machine but I'd probably just go for a 50 kW machine so I get longer to have some food 😊
 

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Over the years, I've seen lots of negative comments towards BEV's without active battery thermal management, mentioning battery degradation, Rapidgate, and other issues.
It's all over Youtube, car reviewers and self-proclaimed experts are actively feeding this argument.

Yet now that the cars with active TMS are aging, they are showcasing LOTS OF ISSUES.
One of the biggest risk is liquid coolant leaking inside the HV battery pack, potentially damaging the batteries but also posing a risk for shorts and fires.

Another issue is that thermal management consumes energy, sometimes lots of it.
In some cases where the battery is purposely heated to decrease internal resistance it may contribute to battery degradation rather than prevent it.

Active thermal management increases production costs (significantly), maintenance costs, operation costs and also battery replacement costs. These systems also add weight.
Yet, cars with such systems are seeing their HV batteries degrade at similar or sometimes higher rates compared to systems with passive cooling.

So in my opinion, while thermal management may be a necessity in the luxury segment where owners can stomach the costs of such a system, I think that it does not belong in the more economical segments, below say £30k.


Thread on Ampera coolant issue Minor coolant issue :D

Video of Bjorn with his early Model S having issues:

Video of a Model X leaking coolant :

A video about the Chevy Bolt HV battery disassembly will help you realise how complex and massive these systems are:
There are arguments for and against, yes, correct.

Bear in mind some cooling approaches don't use water cooling, and may be less prone to failures, eg; air drawn in from outside (eg Soul), air pushed outwards (leaf, I think), air conditioned air pushed outwards (MiEV/eNV200), Peltier coolers (Fluence).

We had a forum member some time back that was hell bent on arguing with everyone that active thermal management was the Devil's own work and was totally flawed. Fact is, it does have its flaws and one can engineer a car with or without it, to varying degrees of cost-down benefit, engineering simplicity, etc..

The problem arising as BEVs have taken on larger and larger battery packs is that they have to be increasingly more dense and heavy. A massive pack which is only passively cooled that gets 'too hot' will take 4 times as long to cool down as one that is half the size/capacity, all else being equal.

Also consider different markets; whereas one might get away with passive cooling for most of the year in the UK, in a Mediterranean country, Calif/Arizona, mid-East, etc., these are markets that probably require active cooling even with optimum conditions, and a manufacturer is hard pushed to argue a completely different car design for one country to another.
 

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It's down to the climate the car is used in and battery size. The bigger batteries take longer to cool down issues with rapid charging etc.

In a climate like the UK with small packs I don't think it's necessary. It significantly add to the complexity and cost of the vehicles.

There were taxi firms using the original leaf that did 100k miles with very little battery degradation. But In the states in a warm climate the batteries do not hold up well at all.

There is an etron owner on here which is on track to loose 6% of it's battery capacity in 2 years at 40k miles . It has an liquid cooled battery. In this case it does not seem to be reducing degradation .

I don't know what the degradation Is like on Tesla's they have a lot of cars in the wild now be interesting to know how well their batteries are holding up. What is the degradation like on a Model 3?
 

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In a climate like the UK with small packs I don't think it's necessary. It significantly add to the complexity and cost of the vehicles.
The counter argument to that is a small pack which can ultra rapid charge is more capable of longer journeys than a larger pack with thermal management issues.

Then there are the resource, weight, cost and integration benefits of a smaller capacity battery.

Take for example the Model 3 SR+, with a circa 50kWh battery and 170kW charging peak, and >100kW charging for much of the curve. Probably more useful than a 100kWh car with poor thermal management over a larger distance.

Take a Leaf e+. Even on a Chademo capable of 70kW, it's almost immediately decreasing the charge rates.
 
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