Battery Recalibration - When Does the Charger Turn Off?

[veimi]

This is my second charge on my new used 2012 ES.

I drove it down to 2 bars to recalibrate it it using my Level 1 8A 120V EVSE.

After 16 hours of charging, there are 16 bars, but both the red dash charging light and the orange EVSE light are lit indicating that charging is still occurring.

I was wondering whether this was characteristic of the charging procedure when the fuel gauge (bars) is out of sync with the energy in the battery.

My RR seems to be remaining the same (steady) at 109 km even though charging is occurring.

I was wondering what determines that charging has been completed.

UPDATE: Even though the fuel gauge (bars) was at 16 after 16 hours of charging with an RR of 109 km, the charging continued for 2 more hours (18 hours total) at which time it shut off with an RR of 110 km.

Hopefully, the range monitoring is now calibrated.

It appears that the length of time it takes to get to 16 bars compared to the total charging time might be an indication of how accurate the previous range calibration was.

 

[mdbuilder]

There is capacity in that 16th bar so of course it lights up and then charging continues as that bar "fills up". Also, once the pack is at 100% there is some balancing that happens at low charge rate. All normal.

 

[Don]

'Range monitoring' has little to do with the charging process - It's a computation of how far you can go based on how and where you drove the last 25 kms. If you want to prove this to yourself, drive it 110 kmh for 25 kms and recharge and see what you get on the RR gauge. Next time, make the last 25 kms you drive at 50 kmh, recharge and check the RR gauge - What a difference!!

The last 10% or so of the charging process involves balancing the battery pack and very little charge is put into the pack during this process. You can unplug when you see 15 or 16 bars and skip this balancing process if you like . . . . it won't hurt anything

Don

 

[veimi]

The last 10% or so of the charging process involves balancing the battery pack and very little charge is put into the pack during this process. You can unplug when you see 15 or 16 bars and skip this balancing process if you like . . . . it won't hurt anything

Don

Thanks for your replies.

As I had mentioned, the fuel gauge (bars) was at 16 after 16 hours of charging, yet it continued to charge with no increase in range for 2 more hours until the charger shut off.

I was also monitoring the kilowatt-hour meter on my house and it appeared that charge was still being applied to the battery during the final 2 hours when it was at 16 bars and no increase in range.

Does this imply that balancing took 2 hours?

 

[mdbuilder]

Part balancing and part capacity of the bar.

I think I read someplace that the bms balancer shunt is something like 80 or 120 mah? and there are four per cell or four per module which would be one per cell. In any case, that is miniscule compared to the cell capacity which is well over 40 amp hours.

 

[PV1]

The stock 8 amp cord takes a long time to charge compared to even 10-12 amps on 120 volts. Before I had mine upgraded, the car would pull the full output all the way to the end and ramp down over the course of 30 seconds, and then shut down charging. There's more capacity in the top bar than most others, as well as the balancing process and current taper (higher charge rate units mainly), all of which make finish charging seem to take forever.

You are also dealing with an unknown battery. It could be pretty well out of balance if the range estimates are off and the charge gauge is acting up.

I'd do a few more 2 bar to full charges and see if things improve. Then I'd look into a level 2 EVSE or upgrading your cord with EVSEUpgrade to improve energy efficiency and speed up charging. I know I was only successful in doing a calibration charge once in the 8 months I used the stock cord. It always took too long. With the upgraded cord, even at 10 amps, the car charges much faster.

 

[kiev]

Yes it could take 2 hours to balance if the car had not been recalibration-charged in quite some time.

The charging current will get pulled back to a lower value when the first cell reaches the upper target voltage, so it will take a while for the laggards to catch up at the lower charge rate. This allows the cell shunts to come on for the high cells while the low ones keep charging. Once they are all within the target voltage range then it will declare the charging complete.

Where are you located--maybe someone close by has CanIon with an OBD-link and can show you the individual cell voltages.

 

[veimi]

Where are you located--maybe someone close by has CanIon with an OBD-link and can show you the individual cell voltages.

Thanks for the offer, but I had already downloaded CanIon and it didn't work with my existing ELM327 bluetooth OBD2 adapter or an Innova 3030 USB scangauge.

I am going to have to bite the bullet and order the Scantools LX or MX.

I live in Toronto, Canada and will update my login profile.

 

[JoeS]

veimi, I see that your questions have been pretty-well answered - I'm curious, do you know the history of your car? For example, if it had been sitting on a dealer's lot for months or years (not unheard-of) it may well take a few recalibration cycles to bring it up to snuff. When you get your LX or MX you'll readily see how well your cells are balanced.

 

[zzcoopej]

I had already downloaded CanIon and it didn't work with my existing ELM327 bluetooth OBD2 adapter or an Innova 3030 USB scangauge.

Hi, our app EvBatMon uses different protocols to caniOn and may well work with your existing OBD (no promises however). If EvBatMon doesn't work with your existing OBD adapters you can get a refund via the Google Play Store. As a bonus via our app you can see the actual remaining battery capacity compared to when the iMiEV was new which is something caniOn can't do. This is a great advantage when choosing to purchase a 2nd hand iMiEV as you can compare the battery degradation of a few iMiEV and choose the best one.
https://play.google.com/store/apps/details?id=com.EvPositive.EvBatMon_iMiEV

I am going to have to bite the bullet and order the Scantools LX or MX.

We certainly also recommend ScanTools OBD adapters for guaranteed compatibility with EvBatMon.

 

[Phximiev]

zzcoopej: How's that 2015 PHEV working out?

 

[zzcoopej]

zzcoopej: How's that 2015 PHEV working out?

The PHEV is fantastic, an excellent compromise in our situation and a perfect partner for the iMiEV for our family. Most of our PHEV trips are <50km eg school runs, however we sometimes do up to 2500km on holidays and there are not many places to charge yet (even if you have a Tesla). Overall petrol use in the PHEV is about 2.3l/100km after about 16,000km.

I gather the USA is finally getting the PHEV in a couple of months?

 

[Phximiev]

Who knows? It's been 'who knows' for months/years.

It should be a great seller here as it was in Europe.