Battery Temps

C or F?

 

I was monitoring 3 of the battery temps. They were all relatively close in temp, IIRC

I havent "Torque'd" in a while.. but here's a graph I made for my 9/25/2012 drive:


I dont remember, and didnt log, what the external temp was.. but being late Sept, it was probably on the warmer side.. maybe mid-70s to low 80s?

I found the historical temp for that day and it was a high of 78F

My battery temps rise at the end because thats where speeds pick up (55MPH) and I start going up hill.

 

Here's another from 11/13/2012. The historical temperature for that day shows a high of 83F. It doesnt seem right though since my battery temps started at about 87-88F. Back then, I was kind of parking in the sun.. very little shade until late in the afternoon.

 

I dont think your numbers are bad.. probably as you pointed out, your driving style.

Looking at my November 2012 graph, see where it plateaus? On that portion of my commute, speeds generally pick up (50MPH posted). But that section gets congested from time to time. It appears that day is was congested since the temps didnt spike like they did my my previous example.

I think with somewhat conservative driving,t he temps wouldnt go up as much or as quickly. Also seeing as how my battery temps dropped a bit in between the two spikes (in the Sept 2012 example), I bet my AC was on.. or at least I turned it on around that time.

I havent logged in a while.. I'll try logging some data this week since its kinda warm here.

 

It should start close to outside temp. It takes a lot of energy to increase the temp of the battery pack. The loss of Lithium is pretty low so you may not even see the fan running.

From my monitorings, I have never seen the battery fan go on.

 

Isn't the PIP also Gen 3 ?

 

Yes!

 

Yes but, Battery tech. is different. in plug in. Lithium runs cooler maybe? so less fan? or the extra fan and vent keep it cooler?

 

Niether my 2005 nor the PIP run the fan, but, that could be mostly because the cars stayed in the garage most of the day. I run the AC when it's hot, which benifits the car also. I went thru a period where I was monitoring the temperatures of the engine coolant and was amazed how low they were compared to a typical ICE machine. Inverter temps were even lower at around 90 - 100F, as I recall. The Prius is a cool running car. Keeping those cooling (fan) ducts open and unblocked is very important in hot weather and/or hard use.

 

Anyone have any charts of battery temps while charging? I did not find any with a quick search of the topic here.

This may be useful for winter EV driving if it shows battery temps are significantly warmed up near the end of a charging cycle. Right now I complete charging at night a few hours before I go out to work in the morning, but if the battery was nice and warm at the end of a charge cycle, I would have it complete right before I left for work to see if that would help EV range.

 

i've never really noticed a difference between cold battery range or warm. nor the ice firing or not. it all seems to be external conditions. but there might be small variations measurable only by instrumentation.

 

You mean your acutal or estimated EV range has been unchanged by the cold temperature of the battery? I think most of us see real and estimated EV range decrease in the winter when battery and outside temperatures are colder. One of the theories is that the cold battery temperature is primarily the culprit. Are you suggesting this may be another phenomenon not related to battery temperature?

 

i'm suggesting that it's the cold ambient temperature controlling actual ev distance and thus ev range estimate. i believe that if it's 30 degrees outside, and you charge inside a heated 75 degree garage, the outside temp as you drive will affect the range by 99% and the heated charging by 1%. not scientific, just observation.

 

wouldn't it depend on how long it takes for the battery temp. to drop from 75 degrees to 30 degrees?

 

agreed......it's only when you stop and park for awhile, for instance at work when it makes a difference.