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Discussion Starter #1
The search engine is a little frustrating here, because I certainly know that some or all of this has been discussed a lot. But when I attempted a search to make sure I wasn't repeating what others have already said, the website froze.
At any rate:
There seem to be some pretty technical discussions on this forum about charging and/or best practices. Until I catch up, I'm looking around on my own and found this article. It seems to confirm what I've already seen here: don't push your battery too hard if you want it to last.
I regret to say that I didn't follow best practices with my two previous leases (which is another little point of data in the argument against leasing) But, like I say, this article mentions some things I was doing incorrectly and would have continued, had I not started reading up. It's approachable for people like me, who aren't real technologically savvy: The Secret Life Of An EV Battery | CleanTechnica
Recently, with my most recent leased car, it spent its entire leased life with me on my home charger. But before I turned it in, I was rattled by the seemingly wild swings it was showing in range.
From what I've seen to date, I have real doubts about any but the most gentle charging plan. Most of the time, I can get away with the low-power charger Fiat supplies with the cars. Maybe 240K is OK. I really don't see why I should exchange immediate convenience (a half-hour charge) for the life of my car.
 

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Lithium chemistry can actually cool by exothermic reaction to the electron flow during charge. These SDI cells have been designed to input/output enormous Amperes.

Will we disable regen braking in the interest of battery pack longevity? I assure you the charge current generated from regen is on a scale that no plug-in charger will ever approach.

Bosch/SDI designed a commercial battery pack that is in good BMS hands. There’s very little we can do to it which will result in radical degradation or increased longevity. That is/was pretty much set when the cells were manufactured and placed into the service system.

IMO most damaging thing is to leave Lithium chemistry sit 100% SOC charge for more than a day or two. In the case of 500e, if you’re not gonna drive for more than 2 days burn off some charge to around 80-90% indicated and sleep well.
 

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Even level two charging is pretty easy on the battery if that is what you are worried about. That is a charge rate of less than 1/2C. The peak voltage the BMS allows is 4.1 volts per cell. So even fully charged the battery is only at 85-90% of it's capacity. The other thing to keep in mind is the BMS only balances when you fully charge the car. If I'm just driving around town, I'll typically charge to 80%. But I will charge to 100% once a week or once every other week to make sure the pack is balanced.
 

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All great points. Basically just plug it into L1 or 2 whenever you can, & forget about it!

Anyone reading that "Secret Life" article should keep in mind that FIat has advantages on nearly all their factors. Here's a breakdown if you want the details:


- "More is Less": As Kiesling noted above, "100%" on a Fiat gauge is really only about 85%, which the article's chart shows MORE THAN DOUBLE THE LIFESPAN as long as you usually charge before it gets below about 25%, which probably shows about "20%" on the Fiat gauge.

- "The Whole Truth": Fiat almost certainly has a low-end buffer protecting the batt, but does NOT have "10 miles in reserve", or even "3 miles". The gauge will hit "0%" when the usable capacity drops to 0.49999%, at which time you can drive about HALF a mile (or a bit more if you go real slow).

- "Virtual Battery": I recently read another article containing that theory. We could actually figure out if Fiat has this issue, by checking if older higher-mile cars charge to a higher voltage reading on OBD.

- "Controlled Voltage": My 2013 with over 24k miles read only 4.1V the last time I charged til it stopped. The chart shows that too DOUBLES LIFESPAN.
HOWEVER, my 4.1V reading was before I realized the voltage drops if you turn on the ignition to check it, & drops even more if DRLs are on, & more still if you start the car. NOW instead of the supposedly required "key on" to check resting voltage, I just open & close the driver's door which gives a short but sufficient window to check the true level, but I haven't done a full charge since then to recheck.

- "Controlled Discharge" is your right pedal. 1C is about 24kW in a Fiat, which is about 70mph. You can set the speedo to show kW. 30mph is about 3kW or 0.125C

- "Don't Leave in Locked Car": Again, we are never at 100%. I wish they had 85% on their chart!

- "Fast Charging": Again, 1C in a Fiat would be about 24kW. Level 2 is only 6.6kW, or about 0.28C. Even the DC kit coming out looks to be only 40kW, which is about 1.7C. Charts I've seen show 2C doesn't age batteries much faster than 1C. At 3C there's more difference, & at 4C it really drops off.
 

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2016 so may not apply much to our 500e but still encouraging to see they "get it" with regard to motive longevity.


“Samsung SDI’s high-speed charging cell is the industry’s top level product, high-powered and long-lasting cell that no performance degradation occurs even after repetitive charging as fast as 80% within 30 min. This is particularly for the commercial car makers who wish to make it possible to quickly charge the car in a short lunch time and drive in the afternoon. This product can maximize the utilization of electric cars for it enables two successive operations in the morning and in the afternoon.”

As I mentioned indicated 80-90% SOC if I were leaving the car sit for more than a few days. Yes, I realize and understand 500e 100% gauge is less than cell spec 100%. So when I shoot for 80-90% indicated via the dash gauge I’m confident this is in a favorable voltage range suitable for even long term storage.

Considering the company lineage of SDI/Bosch developing EV's I’m confident suitable service/replacement battery pack options will become available as needed. The really great part is that it hasn’t been needed much yet.
 

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Discussion Starter #6
I am going to be poring over this. I'd think so should anybody who's decided to make the commitment to buying -- as opposed to leasing -- EV. When you buy, you're naturally more concerned about making the battery last.
But -- speaking for the tech dummies like me in the group -- it would be very helpful to have this explained in kindergarten terms, or at least third grade. One practical application of what I'm requesting: I think I got a car with a really good battery. I'm trying to baby it. But Fiat's charging timer is pretty ham handed. I'd love it if I could program something in the system to tell it rarely/never to charge above 80% and to alert me if the battery were approaching 20%.
It seems like Volkswagen expected EV drivers to be able to cope with stuff like that, assigning a lot of control over how the cars drive to them. The result seems to have been a lot of broken cars.
I bet there's a middle ground between chaos and the middling control I'm after.
Are there any aftermarket/hack solutions out there?
 

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To avoid going under 20% you could watch the % gauge, but I rarely go that low so I can't remember when the car's built-in alert activates. I think it's around 15% on the gauge, which is really about 20% of the battery's true capacity.

Your car already never charges above 85%, but if you really want to try to make your battery last over 500,000 miles, check out the MY500E app. Also, many after-market chargers (including portable plug-ins) are controllable. Check out "OpenEVSE" & "Juicebox".
 

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"For tech dummies in kindergarten terms, or at least third grade", who still want their battery to last over 100,000 miles, just plug it into L1 or 2 whenever you can, & forget about it!


I hadn't heard about "broken" VW EVs, but like a Leaf they have no cooling system AND many have 40kW DC fast charge which is over the base "1C" charge rate, even for the later model eGolf's larger battery.
 

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Discussion Starter #9
To avoid going under 20% you could watch the % gauge, but I rarely go that low so I can't remember when the car's built-in alert activates. I think it's around 15% on the gauge, which is really about 20% of the battery's true capacity.

Your car already never charges above 85%, but if you really want to try to make your battery last over 500,000 miles, check out the MY500E app. Also, many after-market chargers (including portable plug-ins) are controllable. Check out "OpenEVSE" & "Juicebox".
I found a my50eWiFi-Setup app on the Android app store that seemed to be looking for another app before it could function. Is that what you were referring to, or something else?
 

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To avoid going under 20% you could watch the % gauge, but I rarely go that low so I can't remember when the car's built-in alert activates. I think it's around 15% on the gauge, which is really about 20% of the battery's true capacity.
Warnings at 25%, 20%, 17%, 15%, 10%, and 5% (turtle).
Your car already never charges above 85%, but if you really want to try to make your battery last over 500,000 miles, check out the MY500E app. Also, many after-market chargers (including portable plug-ins) are controllable. Check out "OpenEVSE" & "Juicebox".
Absolutely. The real question though is what to look for if an actual range dropoff is experienced. I'm pretty sure I have a compromised battery from some very noticable behaviors (range under 50 miles, 120V recharges from less than 5% to full in about 12 hours). I ran AlfaOBD once with terrible SOH,SOR, SOC numbers (60% range IIRC). But my 2014 drives fine and there are no indicators from the car.

ga2500ev
 

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I found a my50eWiFi-Setup app on the Android app store that seemed to be looking for another app before it could function. Is that what you were referring to, or something else?
my500e isn't just an app. There's a hardware module that runs about $400 that needs to be purchased and plugged into the OBD2 connector for that app to work. You can find more information at my500e.com. Recent posts in the Q/A page indicates that they are soon to release a WIFI only version of the hardware. But that hardware isn't available yet.

ga2500ev
 

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Ran across this today and figured y'all might find it interesting:

 

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...range under 50 miles, 120V recharges from less than 5% to full in about 12 hours). I ran AlfaOBD once with terrible SOH,SOR, SOC numbers (60% range IIRC). But my 2014 drives fine and there are no indicators from the car.
It seems to me you'd get that exact same experience if your % gauge is in dire need of calibration.

Even though you still have a couple years of battery warranty remaining, if you already tried a short 12v disconnect & also non-stop full recharge from dead, the next thing I'd try is 48-hour 12v disconnect.

Someone here (with gauge issues, I think) reported short-term 12v disconnect failed so they were going to try an hour or 2 but then forgot to reconnect for I think a day or 2 (sorry I can't remember if it was only overnight) & then it was fine.
 

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I haven't tried anything yet. The last full recharge from 0% was about 18 months ago. Even then it fully recharged at 120V in about 12 or 13 hours which is woefully short of full battery capacity.

Does the full recharge need to be on 240V? I can pull it off with a bit of setup if necessary.

I may try the 48 hour reset the next time I'm out of town.

But what I really want to know is whether or not there is any truly effective monitoring system for the battery so that we can figure out what's going on. I'm with Sudaval on the fact that if the battery is really going bad that I'd like to have a definitive way of detecting it. Considering I'm going on 3 years with this vehicle and literally the only three problems I've had is tires, wipers, and the passenger side armrest, I'm willing to put some funding into battery monitoring if there's an effective way to do it.

ga2500ev
 

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Me too, & I'm sure many others here. I had high hopes for OBD. There are a LOT of numbers there I haven't explored yet though, so I still have some hope.

Fortunately(?) your SOH readings of around 60% are meaningless, based on one of mine dipping to 59.22% & then rebounding(!) to an obviously impossible 100%.

Yours recharged about 50 miles of normal driving in about 12 hours. That's normal except that the gauge SHOWED "5%" & then SHOWED "100%". Consider that your gauge may be showing incorrectly high, or low (like others here have experienced). I'd check OBD voltage & SOC at full charge (maybe stopping early, reading 100% on the gauge when it's really only half charged) & when the gauge says "5%" after only 50 miles.

My OBD indicates that to recalibrate SOH & SOC it only needs to go to zero. That's probably TRUE zero, so if your gauge is reading 5% when it's really 15% or something, you'd need to run accessories by the charger until it dies. Someone here added the "full nonstop recharge", & I believe someone mentioned 240V, so that's something worth trying if the "weekend 12v disconnect" doesn't work.
 

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Testing and recording DC IR (internal resistance) of any battery pack and ideally individual cells used in series strings is enough IMO to reveal any significant trend of degradation.

DC IR test consists taking note of resting voltage then apply a measured or known Amp power load measuring voltage drop after about 10 seconds duration.

For example starting with 399V pack drive in a manner to pull steady 20kW for about 10 seconds. Let’s say for this example the voltage drops to around 378V. 20kW calculates to around 53A load. I'm just pulling these numbers from air as I have no idea how much voltage drop 20kW actually occurs with our 500e.

Subtract 378 from 399 = 21V drop and divide that by load 53A = 0.396 Ohm multiplied by 1000 = total pack DC IR of 396 miliOhm.

In a perfect world and pack all cells being equal the individual IR of individual cell would then be about 4mOhm. However, cells are never exactly equal and IR can and will distribute unevenly across the series string of cells used in a pack. This is why packs must equalize or balance from time to time.

However, performing pack DC IR test and watching for any significant changes over time can provide a baseline to reveal if the pack and thus any cell IR may be changing significantly.

btw, this method works with any chemistry battery pack. SLA, Nickel, Lithium

Once degradation is noticed then it’s time to apply the same testing but simply measure voltage drop across individual cells in order to identify which cells seem to exhibit higher DC IR than the others.

The needed voltage info for this crude test seems to be available via AlphaODB app and I think the dash kW meter is sufficient to extrapolate Amp load. But I’ve simply been too busy to take the time to learn the OBD interface and pull this data from the system.

If I were to believe my 500e pack were suffering in some manner I would definitely make time to check DC IR but as it stands I just haven’t felt the need or desire to bother yet.

For more details about DC IR testing check this:

 

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Thanks Enyapeoj. Someone previously mentioned that OBD's "SOH-R" reading is likely based on internal Resistance, & therefore pretty accurate, however 30 users report exactly "99.61%", 4 of them with over 40,000 miles, & Ironhydroxide measured a brand new one with only 33 miles at only "73.33%". Maybe the actual IR is buried elsewhere in OBD readings.
 

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Followup on my previous post. Got a chance to run down to 0% last night. Couldn't get the HV battery to cut off, but did get to "Limited Power" where the heater nor AC wouldn't activate.

I plugged in after 9 PM. Just checked this morning at 10:15 AM and the charging was complete and showing 100% charging with an L1. I can do the math. 1.44 kW for 12 hours is 17.3 kWh. So something has to be off, right?

ga2500ev
 

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Testing and recording DC IR (internal resistance) of any battery pack and ideally individual cells used in series strings is enough IMO to reveal any significant trend of degradation.

DC IR test consists taking note of resting voltage then apply a measured or known Amp power load measuring voltage drop after about 10 seconds duration.

For example starting with 399V pack drive in a manner to pull steady 20kW for about 10 seconds. Let’s say for this example the voltage drops to around 378V. 20kW calculates to around 53A load. I'm just pulling these numbers from air as I have no idea how much voltage drop 20kW actually occurs with our 500e.

Subtract 378 from 399 = 21V drop and divide that by load 53A = 0.396 Ohm multiplied by 1000 = total pack DC IR of 396 miliOhm.

In a perfect world and pack all cells being equal the individual IR of individual cell would then be about 4mOhm. However, cells are never exactly equal and IR can and will distribute unevenly across the series string of cells used in a pack. This is why packs must equalize or balance from time to time.

However, performing pack DC IR test and watching for any significant changes over time can provide a baseline to reveal if the pack and thus any cell IR may be changing significantly.

btw, this method works with any chemistry battery pack. SLA, Nickel, Lithium

Once degradation is noticed then it’s time to apply the same testing but simply measure voltage drop across individual cells in order to identify which cells seem to exhibit higher DC IR than the others.

The needed voltage info for this crude test seems to be available via AlphaODB app and I think the dash kW meter is sufficient to extrapolate Amp load. But I’ve simply been too busy to take the time to learn the OBD interface and pull this data from the system.

If I were to believe my 500e pack were suffering in some manner I would definitely make time to check DC IR but as it stands I just haven’t felt the need or desire to bother yet.

For more details about DC IR testing check this:

Awesome post, we need more of this!

Followup on my previous post. Got a chance to run down to 0% last night. Couldn't get the HV battery to cut off, but did get to "Limited Power" where the heater nor AC wouldn't activate.

I plugged in after 9 PM. Just checked this morning at 10:15 AM and the charging was complete and showing 100% charging with an L1. I can do the math. 1.44 kW for 12 hours is 17.3 kWh. So something has to be off, right?

ga2500ev
I'm not sure how you arrived exactly at 12hrs (how do you know it didn't finish at 10:14am?)
The other consideration is not all 17.3 even made it to the battery, y always thought it would be about 85% of that. On the positive side your 120 is likely more like 125v maybe. To me it's clear there's degradation not only on yours but on others too and posts like this are good to have.
 

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Without knowing the exact charging duration and your outlet's actual output you're purely speculating. But now that you're at 100% charged, you can run it down to 50% and go charge the car at an actual charging station. Then you can get a readout of the amount of kWh and multiply that by 2 to get a better proximation of your total capacity.
Followup on my previous post. Got a chance to run down to 0% last night. Couldn't get the HV battery to cut off, but did get to "Limited Power" where the heater nor AC wouldn't activate.

I plugged in after 9 PM. Just checked this morning at 10:15 AM and the charging was complete and showing 100% charging with an L1. I can do the math. 1.44 kW for 12 hours is 17.3 kWh. So something has to be off, right?

ga2500ev
 
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