Plug-In Hybrid Battery Wear

[IveBeenRued]

First hand experience here: I had a 2013 Ford C-Max Energi. I purchased it used at 10K miles at which point I was able to get 23-25 miles on pure electric range in the real world (EPA estimated range was 21). Fast forward to 88K miles, I was down to 11-13 miles with the same commute, similar environmental conditions, same driver.

I personally believe 50%+ loss in range was caused by Ford’s lack of battery management software that should have limited the charge and discharge to an 10-80% SoC. The battery control module would allow for 0-100% SoC. That said, it didn’t do too bad if you think about it. I beat on that poor battery. 9-10 100% charge and discharge cycles per week for 4.5 years; about 2,200 total cycles during the time that I owned it.

Once prices come back down, I’ll be in the market for another PHEV.

 

[dcd]

I need to research more on automotive batteries for PHEV and BEVs. I am more familiar with MW-scale batteries for utilities which use the same basic NMC and LFP cell building blocks. Most utilities will use 4-hour batteries for one full charge-discharge cycle per day. Degradation is expected and is designed for by oversizing upfront and/or augmentation (adding or swapping modules).

Even though the batteries are liquid and/or air cooled, there are warranty limitation to how fast and how frequently the cells can be charged. Faster charging requires a longer cool-off period (as long as a day) before another charge cycle can begin. I’ve read stories like this one about premature failures of Tesla batteries used for ridesharing with frequent supercharging and have to think this could be why.

Back to the original Volt example, maybe one or two cycles a day is not a major issue in a modern PHEV. I have to imagine, though, that it is tougher on the battery than shallow cycling a larger BEV battery.

 

[nobb]

There's many factors, but yes the battery in a PHEV will most certainly wear out sooner than an EV for most applications.

Assuming they are Li-Ion batteries and mostly city driving, a PHEV will be using up the full range of that battery more often. For EV users, they can more easily keep the battery out of the extreme zones (eg. below 20% and above 80%) which helps it last longer. Li-Ion also degrades naturally with time regardless of use so after 10-15 years the battery is most likely a paperweight.

IMO for hybrid and PHEV applications, Ni-Mh may be superior from a robustness and long term reliabilty standpoint as they handle full charge/discharge cycles better than Li-Ion. But of course, the consumer only cares about the immediate specs and not how long lasting their products last. Pretty much all modern electronics using Li-Ion are junk after 10 years simply due to how the batteries degrade. I have some 10+ year old Ni-Mh cells that haven't been used much and they still have the same capacity as when new.

 

[Snagglefoot]

At what % of battery charge will the engine start?

 

[Cujet]

Let's be honest here, we can't count on the manufacturer to choose the right type of cell for PHEV's.

There are significant differences in Lithium cell design and construction for PHEV's as the cycle count for an EHW5, is in the 50,000 cycle range. Generally less energy dense and much more robust construction. Think "thicker" components for an idea of how it's done.

As the OP correctly notes, the smaller than an EV battery pack is called upon to provide all the power and all the regen of a full sized EV pack. Just for not as long. This stresses each individual cell much more. The good news is that there are cells designed for this. The bad news is that some of the "lesser" manufacturers don't use them....

This may be another case of "You get what you pay for".

By the way, the high cycle count batteries have about 80Wh per Kg, as installed. Which is about half of a "as installed" modern pack. Remember, each individual cell in a modern EV will probably be about 250Wh per Kg when software limited. About 290 unlimited.

 

[SEBZX79]

Over and over I hear people, including reputable automotive podcasts, tout plug-in hybrids as as being a substitute for a full BEV (for shorter commutes) with added benefit of not causing range anxiety.

While this is possible, I am concerned they are missing one important point - battery wear. It stands to reason that a 15 kWh battery pack for a PHEV operating as EV-only would see 5 times as much usage as a 75 kWh BEV for the same distance.

Case in point, a coworker has boasted for the past 10+ years about not having to use gas for his 30-40 mile round trip commute with his Chevy Volt. He charges at home and at work.

Just this past year while on a road trip his Volt broke down and had to be towed to a dealership. The dealer said it needed a new battery pack at a cost of $25000. The car had about 70,000 miles on it (maybe less). He ended up towing it to a major city 2 hours away to have a refurbished pack installed for about $8000 at a specialty shop. Even at this lower cost, his car was essentially totaled.

I have to wonder if he would have had a much better outcome with a pure BEV, as he used the gas motor very little and put (I believe) a strain on the much smaller PHEV battery pack. Essentially he put 70000 x 5 = 350,000 BEV equivalent miles on that little 16kWh pack.

I have 3 pheva
2017 bmw x5 40e
118k miles
No issues with battery


2018 bmw 530e
82k miles
NO issues

2022 Jeep Wrangler 4xe
25k miles no battery issues
Only issues is with fuel filler keeps kicking check engine on and off.
My bmws have been rock solid looking to upgrade the x5 to new version around 150k miles.

 

[zyxelenator]

I owned 2014 Volt. Got it with about 40k miles after the lease, and sold it to Carvana 1.5 years ago with 102k miles on the clock. My lifetime mpg was 115. (the first owner used it as a hybrid it seems without charging much). It was still getting 34-36 miles per charge even though my driving was 80%+ in EV mode while I owned it. Reason for sale = It developed an AC refrigerant leak at the heat exchanger factory crimps behind the dashboard. AC helps to cool the battery there(in addition to water cooling), it is a no-no situation in TX heat. I did not want to fork out $3k+ for repairs. On the other hand, my 2018 Outlander PHEV has AC-only cooling for the battery and they all have software problems with artificial degradation. I now get 12-14 miles vs 22 when I got it (after lease the car again)...

 

[dubber09]

IMHO, it's not how phev is meant to run in ev mode only, so 10 years use in ev mode only is pretty good.

 

[michaelluscher]

Given the Volt was one of the first plug in hybrids, I think it’s a bit harsh to criticize its longevity. So it only lasted 10 years and 4,000 charges. Oh well.

I agree
Do we see many Gen 1 Prius (Priui?) on the roads?
I don't, no one bothered to fix them

 

[2strokeNorthstar]

The hybrid battery in my 2021 Sahara 4xe has a 10 year/100,000 mile warranty. I’m not losing any sleep over it.

I would lose a little bit of sleep over a Stellantis warranty

 

[MCompact]

I would lose a little bit of sleep over a Stellantis warranty

Based on the alternatives I'm still not all that concerned.

 

[JHZR2]

If the use case was exactly the same, sure, the smaller battery will be cycled more.

It’s kind of silly to run a PHEV as an EV though. That’s not really the point.

Having some useful EV only range to get some limited capability, is sound.

Now, the $20k for a battery is an issue. Of course, since batteries age with cycles and calendar life, the BEV will also face a certain fate that is far more expensive. Hopefully with stackable standardized packs, they can be replaced as a module, and a PHEV would have one or two standard modules while a bev would use many more.

 

[meep]

I agree
Do we see many Gen 1 Prius (Priui?) on the roads?
I don't, no one bothered to fix them

That’s a good metric. They were known as extremely long-lasting … and basically just aged out. I rode in a gen 1 with over 200k on it a few years back and iirc the owner said it still had something like 70% of its original capacity. They bought it well-used and loved it. By the time I was sitting in it, it seemed small and past its prime for desirability.