EV general discussion
- Thread starter Ricochet J
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Same here. I just plug it in and the Intelligent Octopus Go just gets it charged by the schedule time at 7p.
Zappi is just fool proof.
I just wanted to know if its just me.. I don't think there is any evidence either way if its detrimental to the battery, its just something that changed, and I see screenshots in this thread that have a single overnight session, whereas I get 6..
And yes, I'd love some data on battery behaviour of lots of short AC charge sessions..
For example, look at my teslamate battery health:
See the sudden drop at 5000 miles? Thats the exact point at which I went from 1 or possibly 2 slots a night to 3-6 and as can be seen from the last few points, I've been getting 6-8.
This may just be the stats having to do more interpolation/extrapolation of data so the inaccuracies grow, so just curious..
I'm struggling to see your issue with it, as long as your battery is charged to whatever % you want by the time you want it, what difference does it make if it's in half hour charging slots or one continuous duration?
I just plug in when I get home and let it sort it, as long as I'm at 100% by 7.30am I'm happy.
Edit: just seen your post about potential battery health.
I just plug in when I get home and let it sort it, as long as I'm at 100% by 7.30am I'm happy.
Edit: just seen your post about potential battery health.
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I don't have an 'issue' at the moment, I have an observation that I can see in my battery health data that going from a longer single slot to 6-8 smaller slots, some 5 mins, some 16 mins, some 20 mins had a detrimental effect and so just want to know if this is just a inaccuracy in the way the data is being interpreted, or if it might actually have a detrimental effect.
I do just plug it in and wake up with the car charged, I don't check the octopus app unless I'm changing parameters (time/charge) level, but that doesn't mean that I shouldn't have any concern or curiosity about the high number of slots, especially as I have access to granular data.. I mean I just asked what other peoples experience are after seeing other peoples screen shots which suggests a minimal number of slots and I'm now up to 12 (checking back to earlier in the year) and so naturally am curious..
Since the car is leased, I don't care if it degrades twice as fast, it just goes back at the end of the lease.
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So the battery is now reporting what it was when new? Maybe it was incorrect before when it started to magically get a bigger battery? What should the battery capacity be?
Cells can hold more or less energy depending on charge rate and temperature too.
Cells can hold more or less energy depending on charge rate and temperature too.
No, it thinks 'new' started at 77.4kwh, but over the first few months it kept recalculating the max upwards until it peaked at 79.3kwh, but has been coming down with a couple of notable bumps until it's now estimating 75.7kwh.. Ironically Tesla are quiet about the actual usable capacity, some say 75kwh, some 78kwh, probably as they have different designs of packs in parallel for different regions, and people are probably using similar apps/data gathering to guess what they should be... there is no official number that you can pin on an individual car that I can find that isn't an estimate.
The only reason I posted it was my 'interest' in the sudden dip at 5k miles, which precisely corresponded when octopus went to (12+ now looking at that exact point in time) many slots, and the last two weeks we've had a really high number of slots and its dipped again. I only noticed the slots because we changed the end time or charge level required every now and again..
Just an observation and discussion point that could continually high number of very small AC charging sessions at this high frequency not have a detrimental effect either from the cars BMS having similar algorithmic issues that make it less accurate or even could it affect the cells negatively..
As mentioned, I don't really care, it's expected to have some degradation, its leased, I don't obsess over the data in anyway bar very occasionally looking at it..
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Like most people I just plug the car in and let iGo do it's thing.
The Mrs looks at the schedule to see if she can put her washer and dryer on early.
The Mrs looks at the schedule to see if she can put her washer and dryer on early.
I just wanted to know if its just me.. I don't think there is any evidence either way if its detrimental to the battery, its just something that changed, and I see screenshots in this thread that have a single overnight session, whereas I get 6..
And yes, I'd love some data on battery behaviour of lots of short AC charge sessions..
For example, look at my teslamate battery health:
See the sudden drop at 5000 miles? Thats the exact point at which I went from 1 or possibly 2 slots a night to 3-6 and as can be seen from the last few points, I've been getting 6-8.
This may just be the stats having to do more interpolation/extrapolation of data so the inaccuracies grow, so just curious..
These reports from 3rd party Tesla apps are not based on real BMS data, there isn’t any within the API.
It’s at best a semi-educated guess based on how much % gets added per kWh charged. It’s not at all reliable.
That’s my main motivation for switching over once my Hypervolt V2 is enabled (promised by the end of this year).
Basically yes.
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The Zappi integrates brilliantly and apparently it is one of the best if you also decide to have solar panels and a battery or so I'm told.
Anyone else used the https://chargefinder.com/en/search map? So much faster than the antiquated zap map, pretty decent at showing live connecters etc. as well. I had it booked marked but never used it until today.
It won't be switching 10A. At switch on it will just be the EVSE handshaking with the car and then the charge rate will ramp up.
I was all set to go to Eon Next Drive but after finding out that two colleagues have on going disputes with them and hearing about their customer service (or lack of) I decided to stick with Octopus who have been pretty solid since I switched to them when they launched.
Even at 8.5p/kWh and a currently shocking 2.5m/kWh its less than 5p/mile which is good enough for me!
I can't remember who was talking about the Masterplug charger but I'm happy with my one so far. Picked up the 10m one from Halfords on a BF special for £114.99. My plan was to fit an external plug but the cable is much thinner than I was expecting and sits nicely under the nice thick squashy weather strip on the roller garage door. Cable lives on a hook outside and the EVSE box sits on a shelf in the garage (normally left on) so charging is minimum hassle and no one can walk off with my charger
Agree, I looked in the DB, it's just accumulation of individual charge current data points.
I found the answer anyway to my observations anyway, yes, high frequency short charging can affect the BMS' accuracy on SoC to a small degree and the only negative effect on battery health was in the 2-3% range over 3000 micro-charges (10-15 mins). This was directly from a lead engineer who just finished working on V2G EVSEs as well as solar integration and micro-charging and micro-cycling are things they are still testing.
I’m not a battery engineer but i can’t see that it would fundamentally impact the batteries degradation but more the estimate the BMS is making about its state of charge.
So cycling the battery, (e.g. using it and recharging it normally) would correct and measurement error within the BMS would it not?
Edit: that would probably happen anyway with normal use of the car.
So cycling the battery, (e.g. using it and recharging it normally) would correct and measurement error within the BMS would it not?
Edit: that would probably happen anyway with normal use of the car.
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The info I was given about BMS' is simply they have a mix of algorithms, they have predicted degradation based on usage/mileage etc, they also have quite complex algorithms that blend a lot of data, mainly just accumulation/dissipation integration, the BMS only truly can get a sense of what 0% is and 100% represents when you do a deep cycle.
Their testing keeps the battery between 20-80% during the tests and find variable BMS 'drift' over the entire test, sometimes it's quite a lot, they do the 2 full cycles before/after to therefore know the degradation of the battery at that point, what becomes difficult is how much is from the 'cycling' and how much is 'extra'.. they compare to battery packs just doing regular 20-80-20 charge/discharge cycles but they get a spread of data because every battery pack has some variation of degradation, hence the 'bias' aspect, its not conclusive, but likely a worse case of 2-3%.
They have been testing lots of different micro-charging and micro-cycling scenarios and are working with manufacturers on BMS errors and also feeding back degradation data.
As an example, the different tests for micro-charging/cycling would be something like:
The micro-charging tests where 20-80%, start at 20%, 10 mins on, 10 mins off, and keep repeating until 80% a constant discharge to 20%.
The micro-cycling tests are start at 80%, do 10 mins discharge, 10 mins pause, 10 mins charge until it hits 80%. The discharge rate is varied from low load to high load through the test.
And then at the end, they do a battery capacity test and compare to the normal charge/cycle data.
I thought 2-3% bias was impressive, basically even if their bias is worse case, it's not a lot for what is a quite extreme use case and pretty much negligible in the grand scheme of things.
I think that's the gist, I was also interested if ISO15118 will ever come to home chargers in some way to allow SoC to be directly taken from the car, but politics and the industry are dragging their feet on that.
Why might a battery degrade with micro-charging, even if a tiny amount? No idea, he's not a battery expert and their results vary by manufacturer, as does normal degradation, they just feed the info back, it's primarily the BMS errors they focus on, those need refining to get V2G mainstream.
battery state monitoring technique I posted last week ... power cycling the charging electronics themselves would impact lifespan (how much of your house hold electronics fails when you power it up)
the elexon grid system for generators bid/offers, segments the day in 30minute slots
the elexon grid system for generators bid/offers, segments the day in 30minute slots
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Anyone else getting Octopus iGo constantly splitting overnight charging to lots of slots?
I'm using Teslamate since I got the Model Y to track everything, and in the Octopus app it will charge from 23:30 - 05:30 but in 3-6 slots
Here's the last charging stats reported by the car earlier this week:
The one at the bottom is just plugging in the car, 16 mins before it realises.. but then 6 distinct charging slots.. then the last one is just the Mrs waking the car up before she goes out, so its heating the cabin..
I'll have to capture the Octopus app and correlate it, but it's never just one slot overnight anymore.. it's usually 3-6 from memory
[edit] actually 8 slots is the worst example I can find over the last 3 months..
Mines been doing that since the firmware update to my OHME Home Pro. I plugged in on Sunday and it scheduled around 10 slots overnight just to top up from 59-80%. It's been 15 minutes here, 20 minutes there at low charging rates then a mad rush at 05.00-05.30 at full power to finish up. At least it's all at the cheap rate and the charger actually talks to my car now, unlike before the update when I had to deregister the car then re-register it just for the charger to read the battery state.