Sudden HV overcharging

I've read reports of a rebalancing cycle but never experienced it. Your description is similar to what I've read before.

Do you have the maximum and minimum block voltage? Does the minimum voltage block float between 3-4 or appear to stay on just one?

Bob Wilson

 

Mine went through that cycle once in Chicagoland rush hour. Sitting there stopping and going on the highway with nothing better to do than watch the ScanGauge and wonder if I was cooking the battery. It went steadily up to 99+ %soc, held there for a little bit, then cut off the ICE and drove on electric only for the next mile or so until the soc was down to 60%.

That was a couple years ago, I think. It did another one just in the last few months.

-Chap

 

That sounds kind of like a Civic Hybrid recalibration.

With the Civic the computer gets it's perception of the battery's state of charge by keeping track of how much charge has been taken from and returned to the battery. If for any reason it suspects that it's perception of the battery's charge is straying from reality, it recalibrates that perception, directly verifies the state of charge, via:

* Forced charging
* Limitted assist
* Lock out of engine stop and idle, coupled with raised idle speed

These typically occur when a battery is out of balance, reduced capacity, and so on. At least with the Civic, if they happen very occasionally it's not a concern. But as the battery deteriorates they happen with increasing frequency.

We've got one still in the family, a 2006, and recal's are basically a daily event.

 

This has happened to me also. You were right to cycle the ignition to reset it. This happened to me last summer and hasn't happened since.

 

Just a though but a cold traction battery and forced charge might be a good idea in these winter months. A cold-soak battery would start with all cells at the same state. Start the engine and once the catalytic converters light-off, do a forced charge. Unfortunately, a manual, forced charge would not reach the peak 99% SOC desired.

If someone has one of the knock-off, Techstream-lites, is there a commanded test for traction battery, charge balance?

Bob Wilson

 

happened to me a couple weeks ago when my girl and i were on our way to a party. it was in ev mode, and went from 50 to 34.5 then started charging and went 60, 70, 80, 90 then 95 then i saw 0 for the longest time. she drove it for 10 mil till we got to the party. shut it off and I turned it back on, the soc was 94.5 or something like that. we enjoyed the party then left and the car stayed in ev until it got back into the 65 soc range. been fine ever since. no codes thrown, but when i scanned for codes on scangauge, it showed p 3006 logged. checked it the other day, nothing.

 

I believe this may be true for the Prius too. Looking back, mine did the "overcharging" thing with increasing frequency in the year or so (25k miles) before my traction battery finally gave up the ghost. I assumed that it was attempting to rebalance cells, etc. Eventually, this would be accompanied by the battery cooling fan running more often, etc. It did happen to me a couple of times well before this, so hopefully, the OP's "event" isn't necesarily a sign of traction battery failure in the near future.

 

I'm researching Re-Involt for our Civic. They're offering a replacement battery, same chemistry, brand new cells, claimed 30% more capacity, 3 year warranty. I suspect they use just-in-time manufacture, ie: you order a battery, and they get to work building it. As opposed to getting a Honda battery that might have been sitting on a shelf, for?

The price isn't cheap though: $2700 to Re-inVolt and $300 to the installer. They have an authorized installer just down the road from us, in Seattle. I've talked to both parties, toying with the idea... Anyway:

Their price for Prius batteries is more reasonable, $1875 (plus install) I believe, going from memory.

 

The Honda price probably reflects the low volume and the delay, what it takes to put one together.

Bob Wilson

 

That's what I'm thinking. Prius are so much more prevelant... That'll teach me, LOL.

For me the operative words are "put one together": I like to think Re-Involt batteries will be freshly made and balanced.

 

I think they didn't want any problems on the Gen 1 Prius so they took extra care b4 they released it. They didn't want to give any ammunition for the naysayers.

 

Ifi n fact the ReInVolt replacement battery has 3 times the OE 144 volt, 6 Amp-Hour capacity, that would account for the higher cost. My reading of their web site says that their "Improved" HCH NiMh battery has 30% higher capacity and that (1.3*6 = 7.8) is a somewhat higher capacity than the Prius 200 volt battery (6.5 Amp-Hour), but that would not justify a significantly higher price (fewer cells in series).

JeffD

 

I bought my 2001 Prius in September 2015 and I've been having the same thing happen to my vehicle. The last couple of times I thought it was a glitch and stopped the vehicle to cycle the ignition but I followed this thread and when it happened again recently, I simply let the vehicle run its course. I now find that the vehicle is slightly more eager to rely on the electric motor while driving and has increased my average consumption to 64.2mpg. The ambient temperature for this event to take place was 6 degrees centigrade. The car has done 103000 miles and I wouldn't expect the traction battery to be on the verge of failure just yet.

 

He said he'd aborted the earlier cycles and that would lead to future attempts. I'm thinking keep on and see if another rebalance cycle comes up. Meanwhile, look at minimizing stress on the battery . . . always a good practice.

My recommendation is always, instrumentation like a miniVCI. Then we can survey your traction battery and get an idea of the health.

Bob Wilson

 

I always drive to minimize stress on the battery. I never drive it up a hill with a discharge showing from the battery, I avoid full throttle as much as possible and i always try to cruise at moderate speeds. I think the reason I expect the battery to last longer than typical NiMH batteries is because of the extremely stringent operating conditions that they are under. I read somewhere that the batteries were designed for 150,000 miles, or to last as long as other drive components of typical vehicles? I know that they wont last forever, look at some Nissan Leaf owners with batteries dropping below 75% capacity in less than 48,000 miles. I'm always looking for more information on the car as its very interesting, where might i get one of these instruments from?