Charging 110V estimates becomes a guess-o-meter after joining the 50+miles club?

[KyleH]

I noticed the range estimator finally has caught up with my driving habbits with a very long stretch on the weekends. I think I am somewhere in the 51-53+ miles per charge on the weekend. And now, my Volt is thinking that my range on a full charge is probably about 51. But, of course, my range estimator refuses to display a number above 49.

I have noticed in the last few days that my charging estimates on the 110V is starting to be very off. Last night, it was off by 2 hours. I was up late, and checked the onstar charging estimates at 12am. It was at 80%, and it estimated 3:30am to complete--makes sense, I usually get 10% every hour anyway. I checked this morning, and my onStar TXT was delivered at 5:30am. Maybe a technical error, but maybe something else. I noticed a similar 2 hr discrepency when charging Sat night, but I didn't think much about it. I'll pay another attention tonight.

Has anyone noticed this? I am assuming it is the result of the funny math that prevents it from displaying anything over 50+, but it is getting kind of annoying that my charging estimation has become erroneous. I am thinking that I have to add another 2hrs to the estimates inorder to charge the few miles behind the "49+". Is there something else going on, perhaps? Battery conditioning? Not a big issue, just curious if anyone else is seeing the same.

-KyleH

[BAZINGA]

While I've gone 50+ miles on a charge a few times my daily average (even in triple digit temps) is hovering between 44 and 46 miles.

So I can't add anything else to this discussion until I too roll up consecutive 50+ miles trips.

[tboult]

Charge estimates are a function of battery state, line voltate and temperature. Durring hot days it may estimate longer in the eveining when its still say 90.. but as it cools down it charges faster..


I've had many days of 50 estimated range.. but the high heat (90+ for 8 days, unheard of here in the springs) means I've been using g ECO AC and multiple mid-day runs for errands I've only gotten 48 and 45 the last two days.

[emartin00]

My guess is that the discrepancy may be due to a combination of OnStar delays, and text message delays. I imagine the car has to send a message to the OnStar server saying it is charged, then OnStar processes it and finally sends you a message. I wouldn't be surprised if there is a significant delay there. It probably shouldn't be 2 hours, but it may add up to a significant time.
I only have my Volt set up to charge based on departure time, and it has always been charged when I am ready to leave.

[Cord]

Same here and it is temp related.
As you said it is the estimated time or the battery charging curve via heat.

OR an extra input to the system at charge start times taking into account the addition cooling A/C load.
We are charging an already HOT car (106 F today) and the cooling loop is on when I start charging.

I use low 8 amps 120 Vac and have noted the charge is finished almost 1 hour early-
I park in a outside covered area car port so the car will cool to outside air temp.

[KyleH]

Thanks guys....

I think it is probably more temperature related. I have been stopping the charge near 85% at bedtime in this recent, crazy heat, so I didn't get to check last night.

I usually drive it in sport mode for my short commute for the work-week, so my trip estimates are back down to 45-48 for a full charge, at 85%, the reading is around 39.

Last night's seems to be back normal, although, it was as hot as the day before. at 88%, it estimated to be complete in about 1hr--which is the norm (10% = 1 hr = 4.x miles = 1kwh charged).

(It is good to know that other 50+milers aren't getting crazy readings...it is probably just a fluke with either the TXT messages/onstar's systems, or maybe the hot weather confused the voltage sensors to estimate charging times for that one night.)

-KyleH

[KyleH]

The guess-o-meter came back. I was doing about 45 miles rate on the current charge, used about 20%, charged it back up to 95%, then used it down to 45% going about a rate of 53 miles (thanks forum for the tip about using Fan-only).

As I tried to charge it, the time initially provided an estimate at "11:30pm". I didn't pay attention to the time or how many hours it was. When I looked again at 9pm, it read "11:15pm", but it was at 72%, but the miles said 35 miles (guessing, didn't think to write it down).

My guess is that it was estimating 4 miles per hour and with a normal max of 45 miles, it leaves about 10 miles for a 2:15 hr estimate; however, using my 110V charger, it takes about 3hrs to charge up from 72%.

About 11:30pm, I looked on the onstar app and it read 92% complete, but still reading 11:15pm as the completion time with about 42 miles charged. I got tired, and unplugged it for the night (charging outdoors with risk of a raining slumber).

Oh well. It looks like the % can be trusted more than time estimate or the estimated miles. From now on, I think I will double check the time with the % at 1hr = 10% rate. Especially when my last trip rates > 50miles per charge.

-KyleH

[montgom626]

Thanks guys....

I think it is probably more temperature related. I have been stopping the charge near 85% at bedtime in this recent, crazy heat, so I didn't get to check last night.

Why do you stop at 85%?

[Ron C]

Estimate (n): an approximate judgement or calculation, as to the value, amount, time, size or weight of something. -- dictionary.com

It's not meant to be exact, because exact is hard to predict given the variables that are uncontrollable (ambient temperature, input power condition).

What could explain a 20% error? Input line voltage drop? Overheating of the EVSE - I notice mine getting pretty warm over 10 hours. Other stuff?

Does it make a difference in your behavior, or more of a curiosity? Do you really plan to go out at 3:30 to unplug?

As for display showing >50, I'm pretty sure mine said 52 yesterday morning. I think I would have made it too - went 35 miles on 6.8 KWh, a tad over 5.0 miles/KWh.

[KyleH]

It is more than that. This is the second time it has happened when I have checked near 2-3 hours of the estimated completion where it was off by a full hour. It seems that it does not recalculate the estimate again. (However, when I average around 45 miles per charge, it seems to recalcualte pretty well to adjust another +/- 15 minutes.)

Most of the time except for those 2 times where I went > 50 miles, it is dead-on accurate with +/- 15 minutes. Having it to be this accurate, then off by over 1 hr makes me believe that the estimates becomes a guess-o-meter when your recent driving exceeds 50 miles per charge. Secondly, I think it is another perceived observation by members on the forum that the the Volt will never display an estimate of > 49 miles on a full charge.

I believe that somewhere in the oddity that it will prevent it from displaying > 49 miles makes the time estimates confused when, in fact, your past driving is closer to 53-56 miles or 5.5 miles/kw. Bottom line, at least my conclusions anyway, the % charged is more accurate than the time estimtes if your recent driving history averages > 53 miles per charge.

-KyleH

Estimate (n): an approximate judgement or calculation, as to the value, amount, time, size or weight of something. -- dictionary.com

It's not meant to be exact, because exact is hard to predict given the variables that are uncontrollable (ambient temperature, input power condition).

What could explain a 20% error? Input line voltage drop? Overheating of the EVSE - I notice mine getting pretty warm over 10 hours. Other stuff?

Does it make a difference in your behavior, or more of a curiosity? Do you really plan to go out at 3:30 to unplug?

As for display showing >50, I'm pretty sure mine said 52 yesterday morning. I think I would have made it too - went 35 miles on 6.8 KWh, a tad over 5.0 miles/KWh.