Battery longevity

Sharing my experience:

• 2003 Prius - the NiMH batteries had a weak terminal "O" right that in high heat, +100F, and heavy usage could leak some of the normally generated hydrogen and oxygen to leak out. Over the years, Toyota made significant improvements to reduced battery heating BUT never went to liquid cooling. In 2009, I replaced the original battery with later battery modules and achieved much lower operational temperatures.
• 2010 and 2017 Prius - both were not owned long enough to detect any noticeable loss. The 2010 used the improved NiMH battery modules and the 2017 went with LiON which does not generate gas. Still no liquid temperature management.
• 2016 BMW i3-REx - liquid thermal management of the LiON battery. I last measured 18.5 kWh vs 18.6 kWh.
• 2019 Std Rng Plus Model 3 - indicated maximum range is 236 miles versus the original 240 miles after 20,000 miles and 11 months. There are charts showing typical Tesla battery has an early decrease of about ~2% and then a long plateau before the capacity slowly curves down.

Our best understanding is keeping the battery in the 60-80% range. This preserves capacity by leaving 'head room' for regeneration braking energy. It appears to keep some of the inert layers that form in normal operation away from the 'edge cases' of the battery.

Another important technique is the 30 minute, climate pre-condition of the car. This uses utility power to warm or cool the interior and also bring the battery to an optimum temperature. I set the daily preconditioning for 7:45 AM which means the utility power ends about 8:05 AM.

Bob Wilson

 

Here's a one data point for you from a Chevy Bolt owner.

https://www.chevybolt.org/threads/battery-longevity.35023/

I wouldn't be surprised that 9 to 10 percent of battery degradation is the median value for a liquid cooled EV battery at 100,000 miles.

 

Many ICE engines carry a 3 yr 36,000 mile warranty. That doesn't mean they stop working when they reach that limit.

We had a local member that had 180K+ on his Nissan LEAF. He was an Uber/Lyft driver and used DCFC consistently nearly every day. While he had degradation of the battery (typical of the passively cooled Leaf), it never reached the point that would have triggered a warranty replacement even if the miles/time had not exceeded the warranty limits.

The vehicle you choose, the climate where it is operated, ad well as the usage/charging pattern will all have an effect on battery longevity

 

My 2004 Prius still has its original NiMH battery. I restrapped it in
2016, and do keep an eye on its particulars. It seems to still be
generally fine; maybe a little capacity loss but it can still absorb
400 vertical feet of elevation coming down a mountain road before
hitting the "full" mark at 80% SOC. Now that I've got the Kona and
am driving the Prius less, I've noticed a little imbalance and weirdness
after it [ the Prius] has been sitting for a while, but that has so far
seemed to straighten itself back out after a bit of driving. Without
any obvious "recalibration" cycles, too. I have a couple of spare "good"
modules on deck of roughly the same vintage if it comes down to
playing the whack-a-mole game sometime, but in New England the
car might become a hopeless pile of rust before then. It's had a *very*
good life, and ain't dead yet!

We have to remember that hybrid packs get socked with pretty obscene
charging currents during regen, too, like 100A == *15C* rate into the Prius
pack. That NiMH chemistry just sucks it right up happily, at least for
those short bursts. Big EV packs generally don't have to deal with that
level of abuse, and most of them probably couldn't even in optimal temps.

_H*

 

I got the 2019 Kona with the Lifetime battery warranty. You would have to decide soon on a 2019 Kona.. Not too many remaining..
I got the Kona because of the battery warranty.. If it wasn't for the battery warranty, I would be driving a Model 3..

 

Correcting the autocorrect and added technical details:

• 2003 Prius - the first NiMH batteries had a weak terminal "O" ring that in high heat, +100F, and heavy usage, climbing and descending hills at speeds over 70 mph, could leak some of the normally generated hydrogen and oxygen from the water based, lithium-hydroxide electrolyte. Over the years, Toyota made significant improvements to reduced battery heating by lowering internal resistance BUT never went to liquid cooling. In 2009, I replaced the original battery with more recent battery modules and achieved much lower operational temperatures.

Bob Wilson

 

If that is your concern then go with the 19. The 2020 doesn't have that many or significant changes that will be worth it for you to take it. Your concern is battery? Take the 19 and you'll sleep better at night. It's that easy.

 

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Unfortunately, there is the financial side of the issue.

Secondly, how much degradation of the battery capacity triggers a battery replacement under the Hyundai warranty? That's something you need to know going in.

 

Let me suggest a 2016-2017 BMW i3-REx, end of lease. They are listed just under $20k and provide both 72 mi EV range and 78 mi engine range, a total of ~150 mi. However, common practice is to code the car for more gas in the tank, more efficient driving profile, and the ability to start the gas engine early. The advantage is you can learn a lot of EV lessons with the BMW yet still have a gas engine than can sustain 70 mph on the highway.

A good forum for more details: https://www.mybmwi3.com/forum/index.php?sid=34b54e8908e8baab71987adfbe8cd1b0

Bob Wilson

 

If he wants an electric car and the Kona fits his needs and he is torn between 19 and 20 model years and his concern is the battery, then his peace of mind with the battery will be the better choice for him.

With the amount of miles he's putting on the car I would be surprised if an i3rex will do the job for him. He'd be sitting at chargers or stop at gas stations way to much.

 

Again, there is the financial issue. The peace of mind goes out the window if the buying the car puts him over the edge financially.

If it turns out the battery capacity drops 10% over 100,000 miles, then the battery warranty becomes less an issue unless he keeps his cars for 200,000 miles or more. Unfortunately, he didn't say and we don't know how the battery is going to hold up yet.

Plus, do we know how much capacity loss triggers a battery replacement under warranty? Since we are putting so much emphasis on the battery warranty, it would be good to know.

 

There were some posts about lack of inventory so I wanted to propose an alternative that is our backup for the Model 3. The 1.9-2.3 gal tank fills fast and it has a CCS-1, fast DC charger. Best of all, low depreciation. But his requirements top either of us.

Bob Wilson

 

I think that battery capacity won't drop more than 5 percent on a Kona in 100k miles, probably less. The reason is that the Kona has a 4.7% buffer that will be used up first. Total capacity loss in 100k miles is likely 5 to 7 percent. So, the car will likely lose about 1 to 2 percent of range in 100k miles. Expect another 2 to 3 percent in the next 100k miles as the initial drop is usually more. Unless someone runs the car down below 10 percent frequently and charges to 100% all the time as also uses frequent DC fast charging, I don't see degradation as an issue on a Kona. Most drivers should still see about 85 to 90% of it's original range after 300k miles..That's just my guess based on Bolt drivers who have a very similar LG battery. Let's not forget that LG has very high Cobalt in their batteries and usually high cobalt batteries degrade slower..
While Tesla is trying to get away from Cobalt, their 1 Million mile battery is high in Cobalt..