2022 Toyota Tundra Hybrid

[redpoint5]

I do think one of the promises of hybrid technology is ditching the turbos. Too bad this hybrid isn't powerful enough to not only downgrade engine size, but dump the turbos.

[JSH]

Originally Posted by redpoint5

Regarding the Bolt fires, many people used to be critical of Tesla's use of cylindrical cells because it wastes more materials in packaging and wastes volume due to void space between cells. They argued prismatic and pouch were more efficient and pointed to the fact that most EV manufacturers have adopted these formats. In hindsight, it may have been a wise engineering decision in that it reduces the chance of a single cell defect causing a fire.

I've argued that perhaps a design that requires cells to be defect free might not be safe enough. A single cell having an internal short shouldn't cause ones house to burn down. Perhaps I'm wrong though and cells can be made reliably enough that the risk is low, or it would simply be too many compromises to make an inherently safe battery.

Round cells don't fix the problem and the fact that you need many more round cells for a battery pack increases the risk of a defective cell. Tesla has it's own share of battery fires as recently as 2020.

The Bolt fires are caused by two different manufacturing defects in the same cell. A torn anode tab and a folded separator.

Originally Posted by Hersbird

The hybrid in the Tundra seems pretty mild. More than the Etorque in the Ram but less than what the F150 Hybrid has. I hope they use some kind of reverse power like the F150 has, that built in generator ability is a pretty useful feature on a truck. Otherwise the big news here is Toyota going turbo v6 like Ford and losing the great 5.7 v8 which is a powerful reliable motor.

The Toyota and Ford hybrids are very similar. Both have a single motor between the engine and transmission. The Toyota's is 48 hp* while the Ford's is 47 hp. The Tundra does not have a generator option which I think is a huge miss.

The twin turbo V6 is expected to be Toyota's replacement for their V8 across all global vehicles. Tundra, Sequoia, Land Cruiser, Lexus - everything on the TNGA-F platform.

*Based on hybrid HP - Standard V6 hp - I haven't seen specs on just the motor yet

[redpoint5]

Originally Posted by JSH

Round cells don't fix the problem and the fact that you need many more round cells for a battery pack increases the risk of a defective cell. Tesla has it's own share of battery fires as recently as 2020.

Yes, but the void space is filled with cooling fluid which may prevent a single cell failure from causing its neighbor to ignite. Just a theory anyhow.

How many tesla fires have been spontaneous rather than a result of crash? Of course we need to keep in mind there are many more Teslas in the wild than Chevy EVs, so the fires per 10,000 units are much higher for GMs EVs.

I was very critical of Tesla's decision to go cylindrical as well, but now I'm not so sure. Their larger format ones may end up being a good "all things considered" approach.

[Isaac Zachary]

Originally Posted by Autobahnschleicher

If you go as far as including a hybrid system, you might want it to work effciently so it actualy decreases fuel consumption properly.

Is there a fuel consumption difference between the NiMH Prii and the Li Ion Prii? Last time I checked it was the same between the two classes.

NiMH may be more "leaky." but Li Ion needs more heating and cooling. Ideally with Li ion you want a refrigeration unit to cool them in the heat, even when the car is not in use.

Then again, NiMH batteries seem to last only 12 to 15 years and then suddenly die. Maybe better cooling would help, but Li ion, with proper cooling even when the car is off, should outlast NiMH.

A new OEM NiMH hybrid battery is in the range of $1,600 to $2,000 dollars. I'm not sure what a new Li ion traction battery costs, but a quick search shows $2,900 to $3,300 for the RAV4 Li ion battery.

[redpoint5]

I've not been impressed with the longevity of any NiMh things I've owned. In theory they need less management... the Roomba and Neato vacuum robots that had NiMh batteries would kill the battery in about a year regardless of how often you ran it. The lithium ion replacements people made have gone years and still haven't died yet.

That said, it seems replacing NiMH batteries might be more straightforward for a DIYer like me.

I think I read somewhere that someone was replacing weak NiMH batteries in Prii with LiFePO4, but I could be mistaken. Lithium ion batteries don't like to be charged below freezing as you pointed out.

I expect to either have access to junkyard batteries when it comes time to replace, or be able to affordably DIY a replacement.

[Isaac Zachary]

Originally Posted by redpoint5

I've not been impressed with the longevity of any NiMh things I've owned. In theory they need less management... the Roomba and Neato vacuum robots that had NiMh batteries would kill the battery in about a year regardless of how often you ran it. The lithium ion replacements people made have gone years and still haven't died yet.

That said, it seems replacing NiMH batteries might be more straightforward for a DIYer like me.

I think I read somewhere that someone was replacing weak NiMH batteries in Prii with LiFePO4, but I could be mistaken. Lithium ion batteries don't like to be charged below freezing as you pointed out.

I expect to either have access to junkyard batteries when it comes time to replace, or be able to affordably DIY a replacement.

It seems that there are a few trying the LiFePO4's as a direct replacement in their NiMH hybrids and are having successes, so far at least.

The freezing aspect makes me a bit weary too.

The good news is that the charging characteristics that keep the NiMH batteries within 25 to 75% make the LiFePO4's go closer to 10 to 90% giving you more capacity that way too.

[JSH]

Originally Posted by redpoint5

Yes, but the void space is filled with cooling fluid which may prevent a single cell failure from causing its neighbor to ignite. Just a theory anyhow.

How many tesla fires have been spontaneous rather than a result of crash? Of course we need to keep in mind there are many more Teslas in the wild than Chevy EVs, so the fires per 10,000 units are much higher for GMs EVs.

I was very critical of Tesla's decision to go cylindrical as well, but now I'm not so sure. Their larger format ones may end up being a good "all things considered" approach.

Yes, Teslas have had battery fires while sitting or charging. Here is one from the USA

https://www.washingtonpost.com/techn...04/tesla-fire/

And one from China
https://www.cnbc.com/2019/04/22/tesl...-shanghai.html

I don't know the total number and I really doubt Tesla is making that data public nor do I want to get into a discussion fires per 100,000 vehicles. My point was simply using cylindrical cells and wrapping them with a cooling ribbon doesn't safeguard Tesla from battery fires.


It is possible to build a battery with prizm cells and seperate each one with a cooling plate. The Volt battery (and Spark) were built that way.

From GM:
"The Dana Corp-manufactured cooling fin consists of two lightweight aluminum plates joined by a proprietary clean nickel-brazing process. The carefully designed grooves stamped into the plates form channels that allow battery coolant that is pumped through the pack to flow over the entire cell surface."



https://media.gm.com/media/us/en/gm/...4_battery.html

The Bolt replaced that cooling plate with an aluminum plate that acts as a heat sink connected to a liquid cooled heat exchanger below the battery cells. Here is an excellent tear-down video of the Bolt battery (he has one for the Volt as well)

https://www.youtube.com/watch?v=ssU2...nnel=WeberAuto

To date GM has seen 12 battery fires in stationary vehicles out of 141,000 built. That is not an acceptable number but it puts the risk to current owners is perspective.

There is another huge difference between a Chevy battery and a Tesla Battery. Because the Chevy battery is bolted together instead of glued, GM is able to repair the batteries instead of replacing the entire pack.

"GM said Monday that it would start shipping new battery cells to dealerships as early as mid-October to begin replacing potentially faulty battery modules."

Image the cost if Tesla has to replace every battery in a Model 3 because of some tiny internal manufacturing defect.

[JSH]

Originally Posted by redpoint5

I've not been impressed with the longevity of any NiMh things I've owned. In theory they need less management... the Roomba and Neato vacuum robots that had NiMh batteries would kill the battery in about a year regardless of how often you ran it. The lithium ion replacements people made have gone years and still haven't died yet.

You can't compare battery life in a disposable appliance or something like a computer or laptop to a car. You can design for max performance or max life or a blend of the two. Toyota is very conservative with their hybrid Ni-MH battery packs

[cRiPpLe_rOoStEr]

Originally Posted by Hersbird

I just don't think any turbo gas motor is going to go down in history as a pillar of long term reliability.

I remember Volkswagen claimed in 2003 that it would switch its entire range to turbocharged engines within a timeframe that AFAIK is already gone. Yet there are still some countries where the Volkswagen T-Cross supplied from Brazil is fitted with a 1.6L naturally-aspirated engine, even though in the local market it gets either a 3-cyl 1.0L or a 4-cyl 1.4L turbocharged engines. Even though a lot of failures of 1.0 TSI engines is related to remapping, and in some countries such as Bolivia and Mexico the naturally-aspirated 1.6 MSI prevailed in part due to claims that a 1.0L turbocharged engine would struggle with turbo-lag, I'm sure reliability and some degree of dumbproofing were the reasons why the 1.6 MSI is fitted to most export-bound Brazilian versions of the T-Cross.

[ME_Andy]

The hood on this beast is ridiculously long.

Engine bay length > bed length is not a good look.