IMA Battery Charge Lost

jimzee · 11-23-2011, 11:46 AM

My 2000 5 speed Insight has 25,000 miles on its replacement IMA battery. Once or twice a month while driving with a full charge it will totally drop to 1 or 2 bars. Now you can have a full charge and park it come back to it and have 1 or 2 bars!
Please tell me what is going on.
PS: My Morgan+8, E type Jag, and Lotus Europa do not suffer from these issues. They do suffer from everything else!

Jim Z

retepsnikrep · 11-23-2011, 12:13 PM

Normal behaviour and it's called a "negative recal" on here. Do some searches on it.

If it's happening regulary on a newish battery then it's a bit out of balance so you might want to look at Mike's Grid charger www.99mpg.com

kennysmith · 11-23-2011, 01:29 PM

Quote:

Originally Posted by retepsnikrep

Normal behaviour and it's called a "negative recal" on here. Do some searches on it.

If it's happening regulary on a newish battery then it's a bit out of balance so you might want to look at Mike's Grid charger www.99mpg.com

Probably better to refer to it as "common", but I don't think it is "normal" behavior. I have never seen that behavior in either of my cars and I would be worried if I did. I think I'd be first in line for a grid charger (actually I was first in line for a grid charger, even though I have not seen that behavior--YAY!)

Eli · 11-23-2011, 01:36 PM

It's "normal" in the sense that a recal isn't necessarily indicative of a problem unless it happens frequently. Small errors in coulomb counting can add up over time, resulting in a "benign" recalibration.

What most people don't realize is that positive and negative recalibrations happen all the time. It's just that with a healthy pack, it's hard to detect them on the instrument cluster because they happen at 19 and 3 bars, respectively.

jimzee · 11-23-2011, 01:47 PM

Do I just need to pull the negative cable off of the 12v battery for 10 seconds to bring to system back.

Jim Z

aisbell · 11-23-2011, 02:13 PM

Quote:

Originally Posted by jimzee

Do I just need to pull the negative cable off of the 12v battery for 10 seconds to bring to system back.

You don't need to do anything. The system brought itself back by doing the negative recalibration. After doing so, the charge level gauge more closely reflects the actual battery pack charge level.

If you disconnect the 12 v. battery, the charge level gauge will indicate 0 which clearly does not reflect the actual charge level. The system will force charge at around 4 bars for a while and then will continue with a behind-the-scenes background charge gradually increasing the charge level. At some point, the battery voltage will reach the maximum that the system will allow which corresponds to a charge level of 19 or maybe 20 bars. At this point, a positive recalibration will occur to bring the charge level gauge up to the actual charge level.

**AClewell** · 11-23-2011, 04:41 PM

I am with Peter on this one. If this keeps happening it sounds like your battery needs a good grid charge to balance the cells.

When that started happening to me with my first battery at 124,850 it wasn't long before the IMA light came on. Lukily Honda fixed me up with a "new" battery because at that time warranty was only 125k miles.