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Discussion Starter #1
All the many 500e drivers I've asked say they get MUCH more range than the EPA spec, but a fairly recent discussion among the "battery heads" at PushEVs.com indicates the 500e battery will still have an EPA range of 82 miles after driving 110,000 miles (& 73 after 210k).

This is especially true if you try to avoid letting it sit at 100% (set timer to finish charging shortly before you drive) & keep the battery cool by leaving the A/C on as much as possible while driving & L2 charging. If you turn the fan all the way down & close the vents it's pretty much cooling ONLY the batt, so it only barely reduces actual range & charging speed.

If you have two keys it is possible to leave A/C on unattended: With 1 key IN YOUR POCKET, pull up to the charger with doors locked & A/C on*, open door, hold outside doorhandle open while pushing in fairly hard on inside doorhandle, close door from outside & the key in "ignition" will be locked inside.

*You can leave "ignition" on (plugging in switches it to "accessory" mode) or turn it off & then 1 click onto ACC,
 

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The car will start the AC compressor any time it needs to "boost" the battery cooling circuit. That includes while the car is plugged in, charging, with the ignition off. If there's no call for cabin cooling, the car will block off the dashboard evaporator and only send R134a to the battery coolant evaporator.

The battery can be cooled passively too - that's what the small radiator visible through the opening in the bumper is for.

Really, the only thing I wouldn't do with a 500e is drive it to an airport, plug it in, and let it sit at 100% charge to bake in the summer sun while you're away for a long time. Unlike the Volt and Tesla, once the 500e is done charging it goes to sleep and stops conditioning the battery.

-J
 

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Are you sure that after car is done with charging it will no longer condition the battery? I would expect that the car "keeps an eye" on the battery temperature all the time, or not?
 

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Discussion Starter #5 (Edited)
The car will start the AC compressor any time it needs to "boost" the battery cooling circuit. -J
As noted below, I'm pretty sure that would only happen when DESPERATELY needed (to prevent thermal runaway).

I usually sit in my 2013 while charging (like right now!) & it has NEVER started the A/C compressor while charging.

I was recently charging my friend's dark grey 2015 in the sun when the dashboard readout said 103 degrees & the A/C didn't come on.

The charge rate was significantly slower, so there are probably conditions where turning A/C on makes it charge just as fast or even faster. I've timed it a few times & its usually just barely slower with A/C on for battery longevity.
 

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Discussion Starter #6 (Edited)
Here's a copy of my post on a different thread:

I'm saying A/C on while L2 charging (6.6kW) OR driving, which is often MORE than 6.6kW! (set end button of wiper-stalk to "motor power").

L2 is not really all that fast ("C" rating only 0.25), but depending on ambient temp & how fast you were just driving, It seems to still generate a lot of heat: While L2 charging I turned my A/C off for a bit & when I turned it back on the coolant pipe was so hot I could barely keep my hand on it! That is well over the 113F required to go 210k mi retaining 73EPA.

I've read that the A/C is supposed to turn itself on, but in my test above it did not, so it may only come on automatically to prevent a fire, WELL past the ideal temp.
 

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OK, this deserves some testing. Hard to believe that you would need to turn on A/C manually to have a EVCU to turn it on for battery cooling. I hope you are not right ;)
 

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Today I did a calculation which worries me a little.


I drove 69.8 miles and I had 15% battery left. So for the full charge I would get 82 miles. So far so good.


However, I did 4.75 miles/kW. So I would actually be able to do 114 miles on a 24 kWh charge. Where did the rest of the energy go? I had no airco on, no radio, fans on low, lights off.
 

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Today I did a calculation which worries me a little.


I drove 69.8 miles and I had 15% battery left. So for the full charge I would get 82 miles. So far so good.


However, I did 4.75 miles/kW. So I would actually be able to do 114 miles on a 24 kWh charge. Where did the rest of the energy go? I had no airco on, no radio, fans on low, lights off.
It's normal. you never get to use the full capacity of the battery on electric cars (doing so would drastically shorten its lifespan).
 

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Discussion Starter #10 (Edited)
CORRECTION!!! Subject line results are based on SEVENTY SEVEN degrees!!! (not 113 like I wrote above in post #6)

Please note this does NOT affect the subject line, since the latter is based on range specs & 500e battery cell life expectancy test specs, NOT on total battery capacity specs.

Thanks guys, for bringing this to my attention! Valentijn's numbers imply that 500e USABLE capacity is about 17kWh, which is 72% of the 24kWh spec. That implies an average of 14% buffer at each end.

For example if 100% on the gauge is really only 86%, & 0% gauge is really 14%. Since its even more damaging to go really high than really low, it might be a safer bet that its 80 & 8% (or more likely theres some rounding error above & its 80 & 10).

Repeat: Please note this does NOT affect the subject line, since the latter is based on range specs & 500e battery cell life expectancy test specs, NOT on total battery capacity specs.
 

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Discussion Starter #12 (Edited)
Again: This has no effect on the 73EPA after 210,000mi (if we keep A/C on while driving/charging when possible, & avoid resting at full charge*).

We're now just discussing how much of the 24kWh battery the computer lets us use, which I find interesting ONLY because it means we can expect the subject line results even if we aren't very careful to avoid extreme "States Of Charge" (100% & 0%)

My latest "trip summary" readout inducates a total current usable battery capacity of 18 to 22kWh**

The RANGE GAUGE is based on the last 10 miles, & since my 1-way commute is 10.4, it could give me a more accurate number:
It indicates a current total usable battery capacity of 20 to 21kWh** & an average buffer of 8% at each end.

**The spreads are due to potential rounding error in the readouts. There's a bit less spread with the range guage since there should be no rounding error at 0% if the computer stops you at exactly 0.0000%.

Numbers will be more accurate with multiple readings, or longer "trip summary"s, but any trip that's not VERY close to 10 miles will actually make RANGE gauge numbers LESS accurate, since they're based ONLY on your last 10 miles.

This has no effect on the 73EPA after 210,000mi (if we keep A/C on while driving/charging when possible, & avoid resting at full charge*).

*The reason for these conditions is that the cycle-life test:
A) Charged to 100% & immediately started discharging. (Resting at 100 is known to decrease life)
B) Specified 25C (77F), which my own 500e observations indicate requires A/C, with key on. (Higher temp is known to decrease life)
 

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Discussion Starter #13 (Edited)
CORRECTION: My subject line above is based on cycle-life tests at SEVENTY-SEVEN degrees, (not 113 like I wrote in post #6). That requires A/C, even when it's well below 77F ambient, since the passive cooling system allows the temperature to go well above ambient.

SORRY!!! Here's what happened: I had read a two different tests, one for the cells used in my 500e & one for the upcoming Hyundai eKona that my friend is getting to replace her eGolf. The eKONA test was at 113F. The 500e test was at 77F.


Here are my notes from that test for the 500e:
Bosch-Samsung SDI cells
3200 cycles before 20% capacity loss under the following conditions:
- 20% depth of discharge (charged to 100%, discharged to 20%, & I'm assuming most of us rarely go below that)
- 1C drain (drained in one hour, yes, I know we'd have to drive nearly full-speed to be that harsh, but...)
- 0.5C charge (charged in 2 hours, yes, I know our cars are a more gentle 0.25C, HOWEVER...)
- 25 Celcius! That's only 77F!



& the eKona:
LG Chem NCM 811 cells
1250 cycles before 20% loss at:
- 1C drain
- 1C charge
- 45 Celcius (113F)
 

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Discussion Starter #14 (Edited)
No. My understanding is that once the car is done charging it goes to sleep. It could even run the 12v battery dead while plugged in.
Page 314 of the 500e manual pdf says:

"The preferred way of storing your vehicle for a long
period of time is to leave it attached to a Level 1 or Level
2 charger. The vehicle has a wake-up feature that will
wake the system every 3 weeks and do a maintenance
charge on the 12 Volt battery and also top off the high
voltage battery if necessary."

Since it's wise to avoid resting at full charge, the REAL preferred way of storing is human monitoring (possibly via the APP) to keep it around HALF-charged!
 

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Last summer, in the Virginia heat, it was common to hear the AC Compressor running on our 500e while it was charging.

If battery heat were a problem I really think we'd have seen it by now. But unlike the Nissan Leaf, we have first model year cars running around with the same range they had when new.

-J
 

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The higher the charge rate (6.6Kwh) the more heat generated. The car will turn on the A/C if the battery reaches the temp range where damage would occur. The coolant line being hot is not an indication of the battery temp. A/C refrigerant return lines get hot because of the refrigerant cycle. Feel the line on your home unit on a mild day. What will kill your battery is demanding too much current (Kw) instantaneously when the battery is near it's upper or lower temp threshold. As in stomping on the accelerator when it is cold or hot out. If the dash reads below 50 or above 90 degrees F then drive like it's a gas car. Slow steady acceleration. The demand during hard acceleration can reach 80 Kw. Charging at most is 6.6Kw. You can do more damage while driving then charging.
 

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Discussion Starter #17 (Edited)
Pretty much agreed on most points. 6.6kW level-2 charging generates more heat than a stock charger. Driving 45mph generates even more heat, & I've seen 64kW charge rate under relatively heavy braking. That's why I recommend A/C while driving to keep the battery at its ideal temp.

The car may turn on the A/C before severe damage occurs, but apparently not before moderate damage which can be easily prevented if you wish, by manually selecting A/C.

If the coolant line was always hot it would not indicate battery temp. It became much hotter than usual, which almost certainly indicates that the battery was hotter too: While charging for about 30 minutes with the A/C on, the coolant line was cool. I turned the A/C off for a few minutes & back on, and the coolant line became SO hot I could just barely keep my hand on it! This indicates that the battery had become warmer. Probably warmer than the ideal 77F.

Battery life is maximized by reducing exposure to extremes, including high current, high temperature, high state of charge & high depth of discharge. That's why cycle life tests need to specify how moderate those factors are. For example, in the 500e test I saw, it specified discharged to 20%, 1C discharge rate, 0.5C charge and 77 degrees F!

It's also best to avoid sitting for hours at a high state of charge. Cycle life tests don't account for this. They charge to full & then discharge nearly immediately. We can usually do the same, by setting the onboard timer to finish charging shortly before driving.
 

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the statement about using the battery right after full charge is also in error, and is counter to one of the mainstays of all rechargable battery rules, you want to keep the battery cool, heat is the enemy.... charging creates heat and so does discharging... heating the battery by charging and then immediately discharging it creating more heat is not good... it is definitely not better than letting the battery rest and come back to ambient/normal temps.

i'm waiting for some corroboration by an authoritative source on some of these statements...

some of the stuff here is right but these things i have mentioned are way off base
 
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