Battery Charge Level

[graemed]

Just a quick question to put my mind at ease - I was in slow moving traffic yesterday for about 30 mins, at the beginning most of the times I was moving away I was getting to 7MPH or just above so the car was auto stopping every time, probably about 10 times in a row I'd say, but each time I was slowing the battery was getting a little top up. As I understand it, the battery indicator isn't directly indicative of the State of Charge of the hybrid battery but it was showing about 2/3 full. Then suddenly it dropped to absolutely empty (which I've never seen before) and sat at totally empty for the remainder of the slow moving traffic and didn't attempt to start to charge until I got some speed up. Is this what is talked about when people mention battery recalibration? If so it this ok on a 5 month / 6 month old with 8500 miles? You really notice the difference the battery makes when its not there!

Thanks

Graeme

[clayton4115]

hi

although i dont have a hybrid and i could be completely wrong, it looks like the battery did a dump and needed to do a recalibration.

[joecvt]

Originally Posted by graemed

....I was in slow moving traffic yesterday for about 30 mins, at the beginning most of the times I was moving away I was getting to 7MPH or just above so the car was auto stopping every time, probably about 10 times in a row I'd say.....

Even though a bit off topic, you did mention the 7-8MPH threshold while stuck in traffic:

If you drive through slow moving traffic daily and can't always get up to that 7-8MPH threshold before another AutoStop will occur, I have designed and built the Low Speed Auto Stop controller that will allow more AutoStops in traffic (even if you can only get back up to 4 MPH or less) when you take off from an AutoStop. It tells the cars computer that you have exceeded the threshold MPH (even if you really haven't) and this allows for another AutoStop even at very low speeds. This controller is designed to work with CVT Insights (Gen1 or Gen2). PM me if anyone would like more detail.

JoeCVT = Just your average CVT owner

[MN Driver]

You've described a negative recalibration of the battery. It is normal to get this on occassion and is only an issue if it happens often. NiMh batteries have self-discharge and if the battery hasn't charged enough to do a positive recalibration(I don't how easy it is to top off the pack with the I2) then it will eventually lose where it thinks the state of charge is at and the voltage taps will see one of the stick pairs in the battery or the total voltage of the battery drop below a certain point and it will trigger the battery gauge to go to zero and stop assist until it can charge it up a bit. Auto stop can use a bit of battery power with the engine restarts and based on some reading from other I1 threads and talking with other Insight owners, it seems that they are more likely to occur with slow moving traffic where the DC-DC is pulling power during auto stop and the engine restarts are pulling energy from the pack.

Since this is the first time you've seen it, I wouldn't worry about it.

A question for you: Have you left the car parked for weeks at a time?

[Cobb]

This is "normal". THe hybrid battery feeds the 12 volt side and it doesnt monitor that draw. So as mentioned above, when the pack voltage dropped to a certain point, the car said oh shoot, then it started to recharge. Even if it does not register on the meter, it can do a back ground charge.

When approaching the Fort Lee entrance on Oaklawn Blvd in Prince George I get that same thing. Then 3 stop lights later with no visible regen I suddenly have a FULL BATTERY.

[graemed]

Thanks for the responses. It sounds like there is nothing to be concerned about as this was the 1st time that I'd seen it

Originally Posted by MN Driver

A question for you: Have you left the car parked for weeks at a time?

Well now that I think back to the last few weeks. My car normally does a daily commute of 60 miles a day. Over the past 3 weeks it has been plunged into temps of -10C / 14F and we've had persistant deep snow which has only just started to thaw. Although this car is excellent in the snow (compared to my previous rear wheel drive car) I did work from home for several days so it sat on the driveway then again I've been off work for 4 days so its sat again before the journey described above. It did get 60 mile runs to work and back between these times though I can imagine all this cold probably isn't the best for the electronics as I know that my ipod in the centre armrest just won't power on, on a morning now until I'm half way to work and I'm blaming that to the low temps.

Coupled with this I am guilty of trying to make sure the car is auto stoppable in the traffic. If the traffic is only moving at walking pace, I will usually leave it a couple of seconds after the car in front moves off purely so I have enough space/time to get up to 7 before stopping again. Maybe in hindsight all these factors weren't good for the charge and my battery and lead it to need to do this calibration thing

I'm quite happy now I know its normal

[MN Driver]

I don't see anything wrong with using autostop at all in traffic, in fact, I use is as much as possible to avoid idling. The cold temperature causes the car to draw less power from the pack and the same amount of power drawn causes further sag in the voltage, therefore less power is available to the car and drawing power from the battery becomes slightly less efficient as well and its possible the car isn't calculating the inefficiency during cold and so the car finds itself a little more empty than it expects.

Cobb, the car should be monitoring the draw, it does with the I1, but I have a feeling that at low rates it probably isn't as accurate and possibly reads low. It seems that autostop engine starts seem to not be read properly and don't get accounted forand with the I2 with a bigger engine and a smaller pack along with cold weather, I have a feeling that there is a possibility that with frequent autostop will probably cause a negative recal to happen from time to time. You are also correct with the background charge, the meter on the 1st gen lies to us as well. If the charge is around 2/3 or higher it will not show its background charge and we can watch the battery slowly climb to the top. If the conditions are just right(or I suppose wrong), I've gotten a positive recal from 16 to 20 bars if I have the battery empty and I drive it purposefully with heavy regen until its full. If I let it do its charge on its own, it doesn't tick to the top quickly through the 16 to 20 range. Not sure if any of that helps you with the I2 though since the system is likely quite different considering the decade gap between my 2000 and a 2010.