Andy Swarbrick
Member
Perhaps I had it wrong. I know there's a buffer and 71 came into my head.
Degradation at 37k miles...
- Thread starter FloridaSun
- Start date
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KiwiME
Well-Known Member
The battery is rated by Hyundai at 356V x 180Ah which is 64.08 kWh. The evidence based on SoC(BMS) v.s. SoC(displayed) that LG Chem/Mobis have apparently started with a slightly larger size to meet Hyundai's life specifications is really only of academic interest to us since we can't directly use it.
While the BMS numbers are interesting too look at on every EV, they are just a guess/estimate by the BMS. The only accurate way to measure degradation in usable capacity is to run battery down from 100% to as close to 0% as possible and measure the kWh you are able to pull from the battery. If you're going to compare degradation over time, you also need to have a consistent battery temperature and discharge rate for each test.
It's probably a waste of time for most people. The rest of the car will likely fall apart long before the battery becomes unusable.
It's probably a waste of time for most people. The rest of the car will likely fall apart long before the battery becomes unusable.
FloridaSun
Well-Known Member
This appears to be the case. Unless the battery goes bad, it should be possible to drive close to 500k miles before available capacity drops below 70%
FloridaSun
Well-Known Member
It depends how much highway driving you do.. If I'd drive 80+% highway, I would not get anywhere close to that.. However, since COVID19, I drive about 70% or so around town... Around town, I get between 5 and 6 mi/kwh.. On the highway, I get between 3.5 and 4.7 mi/kwh..
I have gotten as high as 4.7 mi/kwh at 70mph but only when driving behind Semis..
FloridaSun
Well-Known Member
Better get driving
FISHEV
Member
Hahn
New Member
I got 261 one of the few time I've charged to 100%. It's only used locally so I've gone to the charge at 20% to 80% which is suppose to be better for the battery. I would charge to 100% if going on a long trip which I probably won't do, I've got a PHEV for that. I did charge to 100% the first couple of time before I found out about the 20/80 routine.
FloridaSun
Well-Known Member
Kona range is 258 but the car is underrated. The estimated range depends on your driving style and average consumption. If you drive fast and aggressive, your estimated range will be lower.. If you drive around town for a few 100 miles, I have seen as high as 358 miles range
FISHEV
Member
But 356 miles noted above is quite a bit of "underrated". Was that a typo?
Tesla derates quickly as speed goes up (above 60 mph) and temp goes down (60F) and the Kona EV seems to hold up much better in real world driving.
FloridaSun
Well-Known Member
Not a typo. I have actually gotten 358.8 miles on one charge with 29 mile range remaining. I drove to work for 1 week at 55 mph and the AC off in hot temperatures and some 35 - 45 mph driving around town and ended up with 6 mi/kwh. 64 kwh battery * 6 = 384 mile range
I average about 5.5 mi/kwh around town with the AC off.. 5.5 * 64 = 352 mile range..
apu
Well-Known Member
I recently got 340 miles actual(not a GOM guestimate) with 5% SOC left. The key seems to be warm ambient temps around 25C that does not require any HVAC involvement and an urban driving cycle with appreciable regen activity. I can't say I was otherwise hypermiling or anything. Unfortunately in my climate I only get about 4 months of great energy economy. The cold temps are creeping back in. In another month or so my mileage figures will drop by at least 20-40%. I suppose the cold temps are relatively good for battery longevity 
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FloridaSun
Well-Known Member
We have only 2 - 3 weeks every year when it's not too hot but I have never had to use the heater. Even without heater use, the range drops in colder temperatures as it seems that the battery does not run as efficient if battery temperature is below 77 degrees..I recently got 340 miles actual(not a GOM guestimate) with 5% SOC left. The key seems to be warm ambient temps around 25C that does not require any HVAC involvement and an urban driving cycle with appreciable regen activity. I can't say I was otherwise hypermiling or anything. Unfortunately in my climate I only get about 4 months of great energy economy. The cold temps are creeping back in. In another month or so my mileage figures will drop by at least 20-40%. I suppose the cold temps are relatively good for battery longevity
doggyworld
Active Member
Wow.. we consistently get only on average 3.7-3.8 mi/kwh. Mostly hw speeds around 70mph. I think we generally get about 230-240 miles if we charge to 100%.
FloridaSun
Well-Known Member
Of course, on the highway, you won't get that kind of efficiency.. At 70 mph with no AC, I get about 3.8 to 3.9 mi/kwh.. If I drive 70mph behind semi trucks, I get about 4.7 mi/kwh
apu
Well-Known Member
As I typically do more frequent and shallower recharges i.e. from 50-80% SOC I had an opportunity to recently do a couple of deeper rebalancing charges from 15-100% and my BMS now reports 95.5% at 100% recharge which is suggesting just 0.5% degradation in the first calendar year of driving. That's pretty awesome if degradation actually stays linear and the battery doesn't blow up, lol.