same here, although mine's not from HK
I know, but the deviation was not 15 minutes in my case. More like 8 hours
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same here, although mine's not from HK
I know, but the deviation was not 15 minutes in my case. More like 8 hours
My car shows 13A charge limit with the OEM Tesla charger. In one location the calculation is quite correct (it shows about 10% more time than actually needed), in another location it only shows 1/3 of the time needed. It's odd that is seems to be consistent for both locations. I have not seen wrong calculation when charging on any 32A charger.
Last Thursday, I was in the West Drayton (Heathrow) Service Centre, getting help hiding the OVMS cable (which now runs completely out of sight ). While there we put the car on charge on the HPC which is 70A.
The SC manager called me over after about 15 minutes because the charge rate in the car was cycling every 5-10 seconds between 13A and 70A. I had set NO OVMS charging parameters for the location, yet we were able to prove the OVMS module was causing the behaviour because as soon as we disconnected it, the car settled at once to a steady 70A charge rate.
Anyone else found the module interfering with a charge at a location not set up? I had previously set the module to do a scheduled charge at my home, over 50 miles away (so outside any geofence for the area).
It has made me concerned about using the scheduled charging feature for fear of damaging contactors or fans or battery.
). While there we put the car on charge on the HPC which is 70A.The SC manager called me over after about 15 minutes because the charge rate in the car was cycling every 5-10 seconds between 13A and 70A. I had set NO OVMS charging parameters for the location, yet we were able to prove the OVMS module was causing the behaviour because as soon as we disconnected it, the car settled at once to a steady 70A charge rate.
Anyone else found the module interfering with a charge at a location not set up? I had previously set the module to do a scheduled charge at my home, over 50 miles away (so outside any geofence for the area).
It has made me concerned about using the scheduled charging feature for fear of damaging contactors or fans or battery.
Where can I find (if it exists) a single list of all the commands please? I am learning by surprise references over time of new commands eg RADIUS and this one, the function of which is unclear - is it a calculation or does it replicate what LIMIT does?
tomsax
Member
There are potentially three charge limits in play here. The charging unit sends a charge limit to the vehicle via the pilot signal, the Roadster can store a charge limit per location, and ACC can store a charge limit per location. The STAT and CTP command use the Roadster's per-location charge limit.
Example 1 At home we have a 70A Tesla HPC but set the Roadster's charge limit to 32A for our home location. STAT and CTP use the Roadster's charge limit, so the charge time estimate is based on 32A and I get good results.
Example 2 I pull up to a random public charging station which has a limit of 24A. I've never charged here before and thus haven't set a charge limit at this location, so the Roadster defaults to a limit of 70A. Of course the station's limit overrides the Roadster's limit, so the car charges at 24A. When I do STAT, it uses the car's limit, not the station's limit, so it calculates based on 70A charging and I get a wrong charge time estimate.
Example 2 is the case where STAT and CTP need to do better, but you can work around it by using the CTP command and specifying the charge limit: CTP 24A.
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tomsax
Member
I agree that it would be nice to have all of the OVMS functionality available in the smartphone apps, but OVMS is volunteer-powered and improves in the direction and pace of what interests the volunteers. More volunteer programmers are welcome. Anyone who is interested should check out the OVMS developer guide and join us on the OVMS development mailing list.
Regardless of if/when the OVMS smartphone apps get all of the SMS features implemented, I'd strongly recommend AT&T subscribers switch to H2O Wireless. H2O uses AT&T's network, so the coverage and reliability are the same, and they have a plan that's just about perfect for OVMS users. For $10 I get 90 days of service. There's a charge per MB and per SMS message, but it's so low that I've had money left over at the end of every 90-day period since I made the switch in May, 2014. I use SMS with OVMS pretty often, when I'm either working on the OVMS firmware or doing a road trip, the same way I did when I had unlimited SMS messages on the AT&T plan that cost much more.
OVMS H2O Wireless Instructions
There are even cheaper data plans from GeoSIM, but SMS is expensive and they aren't as easy to set up. I prefer H2O Wireless because I don't want to have to think about SMS costs and approximately $3.38 per month is cheap enough for me.
tomsax
Member
The best list of SMS commands is in the OVMS Roadster User Guide, but it isn't always complete. For example, I haven't documented the CTP command.
The CTP command uses the charge time predictor algorithm to figure out a charge time estimate and returns that. It doesn't alter any settings. It guesses at what parameters to use when calculating the charge time, but it doesn't always make the right choice for parameters. To help in those cases, you can specify the parameters yourself. If you know the voltage and current, you can send those.
When charging at home, I have a charge limit of 32A and see a line voltage around 238V when charging. At a public Blink station, I'm likely to see 200V and 24A available. To get the charge time prediction from the current state of charge to full in the current charge mode, I'd send one of these commands:
CTP 238V 32A
CTP 200V 24A
If I'm planning a road trip and want to compute charge times based on expected SOC, I can also send the start and end ideal miles. Part of the reason I haven't documented the CTP command is that it's lame and assumes ideal miles, so folks who think in kilometers have to convert to miles. Suppose I'm planning to charge at a Tesla Roadster HPC that I know supplies 205V at 70A, and I want to charge from 70 ideal miles (Start) to 150 ideal miles (End). Here's the command:
CTP 200V 24A 70S 150E
You can also specify the charge mode (S, R, or P for standard, range and performance, resp.) and the ambient temperature in Degrees C (no support for F, again lameness leading to lack of documentation). So now suppose I want to do the previous charge in range mode and expect the ambient temperature to be 35C (95F). Here's the command:
CTP 200V 24A 70S 150E 35D R
The command arguments are case-insensitive and order doesn't matter, so the above command can be expressed as:
CTP r 35d 150e 70s 32a 200v
It uses the Roadster's CAC value to estimate the ending charge state and charge tapering profile in each mode. If you're really nerdy and want to figure out charge time estimates for another Roadster, you can set the CAC value manually as well (integer values only). So, to figure out the charge time to go from flat empty to full in standard mode at 240V/70A and 30 degrees C for a nominal new Roadster with a CAC of 160Ah:
CTP 240V 70A 0S 160C 30D S
You might also fiddle with the CAC value if CTP isn't doing a good job of estimating your end-of-charge ideal range.
An easier way to try out different parameters on the charge time prediction algorithm is to use the online CTP calculator. The only difference is that the online calculator has you specify the pack capacity rather than calculating it from the CAC.
If I can get improved versions of STAT and CTP working, I'll also try to get the Roadster manual updated to include the CTP command.
Yes, I should add that to my list of software tasks. At the moment I'm investigating differences between the charge time predictor results and reality for my car.
here another example showing 1/3 of real chare time.. Again at the same location. Meanwhile I updated the firmware to the roadster specific build, but that didn't change the behavior
20:14:20
Standard - Charging
213V/13A
Full: 193 mins
SOC: 18%
Ideal Range: 55 km
Est. Range: 47 km
ODO: 38,768.9 km
CAC: 154.03
tomsax
Member
Until we can make a release with improvements, please use the CTP command and specify the correct voltage and amperage. In this case,
CTP 213V 13A
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