So I got jury duty this week, so I get to do some city driving. I'm thinkning great, now I can really put up some #'s if I can get 38+ in the country!!
Well first 2 days it was cold and wet out, only got like 28mpg according to SG! disapointing. So on day 2 leaving the garage, I get to a stop light as soon as I got to the ground floor. And it sounds weird, the charging sound, but 'stronger' maybe, so I glance at the SG, SOC is 28!!! That's after starting and decending 2 levels with brake pedal depressed. I don't recall parking with that low a #, but can't be sure.

So how low can SOC get? Are there different charging levels/speeds like a low/high? As it seemed to sound strange as it was charging at the light, but could have been normal, and I was just more focused on it.

 

I have seen 23% SoC when I spent an afternoon installing a factory navigation radio and door tweeter speakers in my FEH. The vehicle started up just fine but behaved strangely for quite awhile. The most interesting thing was my MxC went to zero when the SoC was still only 38%. When MxC goes to zero there is no regen, and the HV battery temp was good at around 80F.

 

Not sure what would have caused the low SOC to start with but I don't think the 2 level parking lot decent would have helped much in increasing the SOC (via regen) since regen does not occur under 7MPH. I assume that you kept it around/under 7MPH on the way down.

Maybe what you're seeing is part of a coincidentally timed recalibration?

 

Before I programmed SoC in my '05 FEH I ran out of gas with a low battery on my Nav. I drove almost a mile at 40mph in EV to exit I-95 and add gas. My generator and engine made a lot of noise when I restarted and there was no regen in "L" after I got moving. I just thought the SoC was so low the charge to the battery wouldn't allow regen because of overheating as the generator was working very hard restoring SoC. My '09 will not allow that speed or HV drain (32% max) and will slow to a stop at 32% SoC when I run out of gas.

It sounds like 08hybridok had a shutdown HV battery power problem and the system drained down like a key-ON. I guess the 12V battery could also drain down and the D/C - D/C converter could have run the HV battery down trying recharge.

GaryG

 

Bryan-

It is very likely you parked in the garage with a very low SOC.
Then, during the warm-up period, you were going too slow to get any regen, plus, during the warm-up period the FEH uses the battery pack only until the catalyst is warmed up and the car goes into closed loop.
It is not uncommon for the start-up procedure to drain the battery pack 10%.
During warm-up is the only time I've seen the battery go down below 35% but it's pretty common during this time.

The few recal events I've seen take the battery pack very high, not very low.
It is possible for recals to go both ways though.
The Honda Hybrids, which have been on the road for more years, and people know more about them, use the same types of batteries.
The Honda's have both kinds of recal, but the charge-up recal frequency is greater than the discharge recal.

All in all, your car sounds "normal". Mine has behaved as you describe.

To explain what Carl was seeing, during a charge, the voltage goes up much higher than normal... 400 volts. At this point, the FEH cannot accurately compute the SOC. To avoid the risk of over-charge, the FEH must let the battery "rest" without charge and let the voltage drop for a few seconds. I suspect this is also a precaution against over-heating. During a strong charge, it is possible for individual cells to heat up faster than the fans can carry away the heat. If Carl's pack average was 80, individual cells could be much more.
Voltage in the mid-range cannot be used to calculate SOC. However, a rapid voltage rise WILL indicate a fully charged battery. During a stong recharge, the FEH will take short breaks from charging to both avoid over heating, and getting false SOC calculations. It will on again and off again allow regen t a really high level. I've gotten SOC above 80% on a long Colorado downhill, but only with almost rythmic bursts of regen every so many seconds.

HTH,
-John

 

This sounds more like it, I got some EV that morning, even suprisingly up most of the steep garage, and when I parked I thik I recall low 40's SOC. It was cool when I left (62ish) plus in shade, so starting up would have knocked the SOC down, and driving it to the down ramp in warm up would have dropped it even more.

Guess the regen at the light was just more noticable because I wasn't expecting to need any/little.

 

I was going to ask if you remembered how you got to the 2nd floor. IE in EV or gas on. That could of lowered your SOC befor parking...