Car stopped charging temporarily

I've had my 2011 ion for 3 months now - still enjoying the experience but had a problem today.

Anyone else ever experienced the following?

The car had 9 bars of charge. I was going on a 40+ mile journey with most of that in 60+mph/100km/h traffic so I wanted to charge up.
I plugged the car in at home on the 10amp 240v charger - usually runs at 2-2.2kw.
The car was plugged in for an hour and then I went to check. I noticed that the charger was only putting in 7 WATTS but had been charging at a higher rate because the battery had 11 bars. I checked the EVSE and it still had the charge light on and was not showing error.
The car still had the red charge light on and was not flashing.

I unplugged the EVSE and replugged it back in again. Again the same happened, getting around 7 Watts into the battery and then after a while it went up to 2kw. Still charging now so I will wait and see.

Luddite said:

...the same happened, getting around 7 Watts into the battery and then after a while it went up to 2kw. Still charging now so I will wait and see.

Click to expand...

Hello Luddite, Everything is OK, perfectly normal.

What you experienced is the "timeout" that the car's internal c h a r g e r takes after it has been charging for a bit - your one hour is typical. This "timeout" lasts anywhere from a few minutes up to about 20 minutes (I'd need to look up some early posts where we discussed this, together with a graph of the ac power).

Speculating, what the car is doing is stopping the charge to determine how much sag there is in the pack and perhaps in individual cells as well, prior to continuing on with the charging. This design feature is incorporated in some c h a r g e r s that I'm familiar with, most notably a West Marine manually-programmable 12v 30A unit. For example, if trying to charge a 12v battery with a shorted cell, the c h a r g e r might happily pump in the programmed 10A into the battery and show, for example, 13V as it is doing this (on the way to, say, 14.4v), but the instant the charging stops the voltage will plummet, telling the c h a r g e r that something is wrong which results in the c h a r g e r stopping the charging cycle. In the i-MiEV, it seems that they allowed some time for the battery to settle a bit while watching it before continuing with the charging.

Edit: Here's a graph: http://myimiev.com/forum/viewtopic.php?f=23&t=270&p=11328

Note, I put in spaces in the word c h a r g e r to keep from showing the automatic charger link that this website generates

Thanks for this, JoeS.

Put my mind at rest. Seems the BMS is smarter than average!