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I have a question regarding how temperature affects battery energy as measured in kWh. I left the house this morning with WattCat reporting 40.5 kWh and came home after a 6.5 mile drive with 43.95 kWh showing - a gain of nearly 3.5 kWh. The ambient temperature was 20 deg F warmer (50 deg F) than the previous 10 days or so. Can warmer temps account for the significant "gain" in kWh as energy is denser in warmer environments? Thanks!
Yes absolutely. Batteries have a sweet spot. Below that the amount they can discharge decreases first slowly, then rapidly with temperature. But there are also idiosyncrasies with the way the API backend calculates charge. Remember, WattCat only reports what comes through the JLR software black box, which is probably broken in places.
 

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I have a question regarding how temperature affects battery energy as measured in kWh. I left the house this morning with WattCat reporting 40.5 kWh and came home after a 6.5 mile drive with 43.95 kWh showing - a gain of nearly 3.5 kWh. The ambient temperature was 20 deg F warmer (50 deg F) than the previous 10 days or so. Can warmer temps account for the significant "gain" in kWh as energy is denser in warmer environments? Thanks!
Yes absolutely. Batteries have a sweet spot. Below that the amount they can discharge decreases first slowly, then rapidly with temperature. But there are also idiosyncrasies with the way the API backend calculates charge. Remember, WattCat only reports what comes through the JLR software black box, which is probably broken in places.
Thanks to both Mike and Sciencegeek! Great explanations. Cheers.
 

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Ever since I had the h264 update my battery health saids 62% on wattcatt before the update it showed 100 %,is this because my battery is not updated to 16.2 or 18.2,or is it a problem with the wattcatt app since the h264 update,I have no way of knowing on my update screen it doesn’t say what battery version I have,is there anyway on the wattcatt app to tell what battery version I have,any help will be appreciated thank you
 

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Battery Health reported by the API is unreliable, which is why WattCat has a toggle to turn it on/off and a disclaimer in the Settings.
 

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oops forgot the attachments

N.B.: "API" stands for "Application Programming Interface", which is just to say that this comes from JLR's real time database, which WattCat accesses.
Sciencegeek is the OBD-2 Scanner Interface you're using in those example available to other I Pace owners yet, If so I sure would like to purchase the App.

Thanks Mike
 

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Thanks! It was about time a proper logo was added. Android's adaptive icon framework is also pretty cool.
I just installed WattCat and here are some readings from Charging tab: Battery, health:62%, 41.25 KWh CHARGING 50%, 104 Mi +2/h (0.9kW). Does that mean the battery capacity is 82.5 KWh instead of rated 90 KWh (not too bad?), 208 rang (bad?), and 62% of health (very bad)? Thanks.
 

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I just installed WattCat and here are some readings from Charging tab: Battery, health:62%, 41.25 KWh CHARGING 50%, 104 Mi +2/h (0.9kW). Does that mean the battery capacity is 82.5 KWh instead of rated 90 KWh (not too bad?), 208 rang (bad?), and 62% of health (very bad)? Thanks.
The battery health is not correct since the H264 update and you can disable it in Settings if it bothers you.
The car battery is 90 kWh but not all of it is available to the owner to protect battery life. Jaguar has said that 84.7 kWh is the usable capacity and in cold weather I see 81-82 kWh at 100%. The other day temps were in the low 60s and I saw 83.5 kWh. Each charge to 100% will show slightly different numbers and yours seem fine.

The range prediction system adjusts over time to your style of driving, your normal use of climate control and accounts for outside air temperatures. Cold weather means less range. Try charging to 100% to see what the system is predicting as it may be more than 208 miles. Either way, 208 isn't bad and seems pretty realistic.
 

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I posted this on another thread initially, but it occurred to me I should have mentioned this here first. Here is a copy into this thread:

I started writing an iOS version on Sunday but still have my real work "interfering" during the week (although I'm working remotely from home). I do have the initial authorization/login/registration steps working from my iPhone and I can pull the status data and lock the car so far. That was a fun step!

I don't know how long it will take me to do an acceptably demonstrable version since I wasn't worried about the UI at all so far. It will be quite a few weeks I'm sure. For now I was just working out the details of the API calls needed to get a basic app up and running. It will certainly take a while to get it looking as good as ardevd's work with WattCat. The app itself will also be more difficult to distribute due to Apple's stricter app distribution controls. In any case if and when I get an acceptably sharable iOS version going I'll post something and we can start some limited testing. A ton of thanks to ardevd for providing the initial app, whoever put up the API docs (which has some errors by the way), and whoever created the Python interface version that I've been referencing to decode some of the mysteries of the API.
 

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For the last 2 days Trips in both InControl Remote and WattCat show starting and ending location as Unknown. InControl journey route maps show my trip accurately but WattCat won't display the maps and the app stops. Has anyone experienced this issue? Thanks.
 

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For the last 2 days Trips in both InControl Remote and WattCat show starting and ending location as Unknown. InControl journey route maps show my trip accurately but WattCat won't display the maps and the app stops. Has anyone experienced this issue? Thanks.
Yes, just checked InControl showing route maps correctly. But with unknown start and end. Don't use WattCat so cannot confirm that.
 

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The battery health is not correct since the H264 update and you can disable it in Settings if it bothers you.
The car battery is 90 kWh but not all of it is available to the owner to protect battery life. Jaguar has said that 84.7 kWh is the usable capacity and in cold weather I see 81-82 kWh at 100%. The other day temps were in the low 60s and I saw 83.5 kWh. Each charge to 100% will show slightly different numbers and yours seem fine.

The range prediction system adjusts over time to your style of driving, your normal use of climate control and accounts for outside air temperatures. Cold weather means less range. Try charging to 100% to see what the system is predicting as it may be more than 208 miles. Either way, 208 isn't bad and seems pretty realistic.
You are right. I charged to 100% and the final readings are: 85.85 khw, 237 miles, 84% health. Not sure how real those numbers are. The bottom line will be how may miles it can actually deliver and that will tell the true battery capacity. I will take a trip to see what will happen. Thanks.
 

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You are right. I charged to 100% and the final readings are: 85.85 khw, 237 miles, 84% health. Not sure how real those numbers are. The bottom line will be how may miles it can actually deliver and that will tell the true battery capacity. I will take a trip to see what will happen. Thanks.
The kWh is pretty accurate based on some massaging of API data. Again, battery health is not accurate and you'll see it drop as the SoC drops. Please ignore it and hopefully this will get fixed.
 

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Well I think one has to accept some glitches now and then. Given that the reporting of location is dependent on both GPS and Cell service there are bound to be times when there's a dropout. I'm surprised is works as well as it does overall.
 

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Discussion Starter #180
A ton of thanks to ardevd for providing the initial app, whoever put up the API docs (which has some errors by the way), and whoever created the Python interface version that I've been referencing to decode some of the mysteries of the API.
I'm the one who wrote it all. If you've found errors in the documentation I would really appreciate it if you could let me know what they are so I can update the docs. Feel free to create an issue on the jlrpy repo on GitHub.
 
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