JoeS
Site Moderator
Posts: 3512
Joined: Thu Dec 15, 2011 5:47 am
Location: Los Altos Hills, California

Charging Interruption

Sat Feb 25, 2012 8:46 pm

Has anyone else noticed an interruption in the power drawn by the iMiEV charger? I've seen it occur using either the Mitsubishi 120v EVSE or my SPX, at both 120vac and 240vac. The interrupt lasts anywhere from a couple of minutes to about 20 minutes. At least once it simply stopped charging completely (over two hours) and I had to shut off power to the EVSE and then turn it on again, after which it did just fine. The following image was taken this evening off my TED 5000 display on my Mac. The blue line is the iMiEV Level 2 SPX EVSE power, the red line is voltage, and the green line is a separate power experiment I'm running on a different branch. This particular interruption lasted about ten minutes.

Image
EVs: 2 Wht/Blu SE Prem., '13 Tesla MS85, 3 156v CorbinSparrows (2 Li-ion), 24v EcoScoot(LiFePO4)
EV Conv: 156v '86 Ram PU, 144v '65 Saab 96
Hybrids: 48v1kW bike
ICE: '88 Isuzu Trooper. Mothballed: '67 Saab (orig.owner), '76 MBZ L206D RHD RV

jennrod12
Posts: 223
Joined: Sat Feb 11, 2012 8:51 pm
Location: Santa Clara, CA

Re: Charging Interruption

Sat Feb 25, 2012 11:36 pm

I have a hard time even telling that the car is charging when I'm using the stock 120v EVSE, I rely on the little charging light on the dash being lit and assume that it is. It's so quiet. What do the lights do on the car and the EVSE during this interruption, anything different?

Jenn
2012 Diamond White i-MiEV ES
with green racing stripes and hubcaps (thanks to WeeJohn)
Santa Clara, CA

jennrod12
Posts: 223
Joined: Sat Feb 11, 2012 8:51 pm
Location: Santa Clara, CA

Re: Charging Interruption

Sun Feb 26, 2012 12:05 am

Right after I wrote that, I went out to the garage and the charging car was dead quiet, as usual. Suddenly it seemed to "turn on" and I could hear it charging, though still pretty quietly.

Jenn
2012 Diamond White i-MiEV ES
with green racing stripes and hubcaps (thanks to WeeJohn)
Santa Clara, CA

jjlink
Site Moderator
Posts: 393
Joined: Sun Sep 11, 2011 8:26 am
Location: San Francisco Bay Area, CA

Re: Charging Interruption

Sun Feb 26, 2012 8:06 am

Sure, I see it about 1:30am when starting to charge at midnight.

Image
i-MiEV Charge Intterupt by JJLINK, on Flickr
John - 2012 Silver i-MiEV SE model, Jan 19th, 2012 w/OpenEvse, caniOn,& OVMS.

JoeS
Site Moderator
Posts: 3512
Joined: Thu Dec 15, 2011 5:47 am
Location: Los Altos Hills, California

Re: Charging Interruption

Sun Feb 26, 2012 8:14 am

Hi Jenn, what you're hearing I think is a pump of some sort running intermittently back there, and I swear I can hear gurgling sounds as well. The actual charging is silent. On my SPX, suspended charging produces a solid green light instead of a blinking green light. On the Mitsubishi charger I forgot to note what it was doing when it suspended charging.
EVs: 2 Wht/Blu SE Prem., '13 Tesla MS85, 3 156v CorbinSparrows (2 Li-ion), 24v EcoScoot(LiFePO4)
EV Conv: 156v '86 Ram PU, 144v '65 Saab 96
Hybrids: 48v1kW bike
ICE: '88 Isuzu Trooper. Mothballed: '67 Saab (orig.owner), '76 MBZ L206D RHD RV

JoeS
Site Moderator
Posts: 3512
Joined: Thu Dec 15, 2011 5:47 am
Location: Los Altos Hills, California

Re: Charging Interruption

Sun Feb 26, 2012 8:21 am

jjlink, thanks for posting your graph, as it confirms that it's the iMiEV's charger which is causing the interrupt. I'll speculate that it could be part of its internal BMS calibration routine. Not a problem, IMO, unless it stops charging completely - especially if one is on the road and needs the charge to get home.
EVs: 2 Wht/Blu SE Prem., '13 Tesla MS85, 3 156v CorbinSparrows (2 Li-ion), 24v EcoScoot(LiFePO4)
EV Conv: 156v '86 Ram PU, 144v '65 Saab 96
Hybrids: 48v1kW bike
ICE: '88 Isuzu Trooper. Mothballed: '67 Saab (orig.owner), '76 MBZ L206D RHD RV

Wee John
Posts: 134
Joined: Thu Jan 12, 2012 6:15 am
Location: SF East Bay

Re: Charging Interruption

Sun Feb 26, 2012 10:53 pm

I did notice it, the charging light was still on and the cooling pump also continued to cycle so I put down to the charger having to cool down, but I guess from what you guys have is that it only does it once in a charging session.

Barbagris
Posts: 230
Joined: Wed Feb 20, 2013 8:34 am
Location: Bilbao, Spain

Re: Charging Interruption

Sat Jul 13, 2013 12:23 am

Hello.

I recently purchased a electricity consumption monitor and I found this strange behavior. I thought to open a new post, but I thought maybe I had been discussing, and I see that it is.

Three days I've looked, three days I see that interruption in loading, and continues thereafter. I have no idea why.

Image
(the picture is all the electricity usage in 24 hr at home, but the marked zone is almost the car carger)
...learning...

peterdambier
Posts: 284
Joined: Thu Oct 04, 2012 3:26 am
Location: Bergstrasse, Germany

Re: Charging Interruption

Sat Jul 13, 2013 1:43 am

From what I have learned, guessing what is in the battery is tricky at least.

When voltage suddenly drops and does come up only slowly after removing the load, that is empty but still leaves room for bottom balancing.

When voltage and temperature suddenly rise it must be full. Quick chargers do stop at that point and battery gurus say it might be a good idea for slow chargers to stop as well.

The BMU keeps track of our state of charge by counting ampere hours in and out but it needs the endpoints every now and then to recalibrate.

If you stop somewhere in the middle and watch how fast voltage drops and compare with temperature you get and indication of state of charge and of battery health. That point is chosen randomly to build a more complete picture by adding the results from different charges.

When integrating (time and amps) you see it is not much that gets into the battery after the constant current phase. That is why the gurus say it is not worth to risk battery life for that little and after several charges that final charge might steal more from your battery capacity than you gain from "overcharging" in the first place.

Going long distance with several power sockets visited I try to stay above 3 bars and rarely go above 14. So I can charge the full 16A most of the time saving time.
Peter and Karin Dambier, DL2FBA, www.piraten-fraktion-bergstrasse.de

Don
Site Moderator
Posts: 2704
Joined: Thu May 10, 2012 3:55 pm
Location: Biloxi MS

Re: Charging Interruption

Sat Jul 13, 2013 5:46 am

First, I know absolutely nothing about the BMU in our cars other than what little Mitsu has shared with us . . . . I've read everything I can find, but they're not revealing too much
peterdambier wrote:If you stop somewhere in the middle and watch how fast voltage drops and compare with temperature you get and indication of state of charge and of battery health. That point is chosen randomly to build a more complete picture by adding the results from different charges.
It makes perfect sense to me that this interruption in the charging cycle is evidence of the BMU at work and Peter's answer above seems logical and makes sense to me. I'm guessing he's pretty accurately described what's happeneing

Many here have converted cars to EV's and others have built EV's from scratch. I haven't, but I considered doing so for a long time and read everything I could find on the subject. You can buy pretty state of the art components - Good motors, motor controllers, LiPo batteries, chargers and even BMU's which control the charge process and help equalize the cells as they charge, but . . . . if you buy the best components available and put them in an old ICE with 100K on it, you're going to spend $20K (not counting your labor) and you're still going to have a 100K car (which probably needs a paint job) and you still won't have anything remotely like what you get when you buy an iMiEV. You may not have air conditioning or power steering and you definitely won't have a battery system likely to last you 3,000 charge cycles and 100,000 miles. I'm not aware of any standalone BMU system on the market which cares for a battery pack like the one which came in our car . . . . period

When I test drove the iMiEV, I was DELIGHTED - I told my wife I could easily spend nearly as much money and the better part of a year of my time and still not be able to build an EV half as good as this one. Buying this car seemed like a 'no-brainer' to me . . . . and that was before Mitsu kicked in a $10K rebate

Don
2012 iMiEV SE Premium, White
2012 iMiEV SE, White
2017 Chevy Volt Premier
2014 Ford Transit Connect XLT SWB wagon, 14,000 miles
1979 Honda CBX six into six

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