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Kona EV, 64kW Premium Nav 2019
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Discussion Starter · #1 ·
We are away tomorrow for a long weekend (without the Kona)

Wondering whether there is any logic to suggest one should not leave a Kona (maybe any EV!) plugged in whilst going away?

My logic to leave it plugged in is two-fold: firstly, it will be about 60% full when we go, & it can top up with solar energy 🌞 ....but also there is a small thought in my daft brain to suggest it would be even harder for anyone to steal it 🦹🏻‍♂️

The flip side of my brain says "ooooh, it could catch fire like those others" 🔥....but it is only on a home 7kW Zappi

Thoughts?
 

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Nissan LEAF30
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Beware the 12v discharging and the car being unusable when you return. In theory the 12v should be topped up by the HV battery but with some systems being kept awake to check on charging it might not retain a full charge.
 

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Kona EV, 64kW Premium Nav 2019
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Discussion Starter · #4 ·
We've done it before, I just got to wondering......!!
 
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I've done this several times, and used to ALWAYS do it when I owned a Tesla, as it wasn't unknown for that to randomly increase its phantom power drain when parked. Leaving it plugged in causes no harm at all, as the charger will shut down when the BMS signals that the battery has charged to whatever level has been set (for cars that allow this), and similarly if the BMS detects that the battery has discharged a bit it will signal the charger to request power from the charge point to top it off.

99% of the time when parked up and plugged in for a time like this the charge point will be turned off, and sat in the "ready to charge" state. It doesn't really draw any more power when it is in this state than when the car is unplugged (technically it may draw around 60 mW more). In this state there won't be any power being supplied to the charger, as the charge point contactor will be open, so the cable connected to the car will be dead whenever the charger isn't actually running.
 

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I would always leave it plugged in when away for more than a few days. With the Kona you can set the maximum charge level to something like 80% so it isn't going to sit at 100% for a long time.
 

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Leave it plugged in and limit the charge to 80-90%. I would not let it sit for several days at 100% charge.

Other than that enjoy your long weekend.
 

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I guess you have to set a time schedule otherewise it will just reach the percentage and stop. Whereas if set to charge for say an hour a day, even though plugged in will it start charging again next day if there is a deficit? I have never tried this.
 

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We went away for a week and left the Kona in the garage - unplugged.
On return I can't say I noticed any reduction in range shown, nor any other problems when I drove it out of the garage and recommenced normal usage.

Recently we had an area power cut, long enough to reset all of our clocks etc.
Not sure what that might have done to the Kona's charging regime had it occurred whilst we were away.
Probably nothing?
Worth the risk? :unsure:
 

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A week really isn’t going to matter even at 100%
And it won’t be at 100% anyway, EV batteries always have headroom left by the BMS, you’ll be lucky if an indicated 100% would be near 90% of true capacity, same for the lower levels.
 

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And it won’t be at 100% anyway, EV batteries always have headroom left by the BMS, you’ll be lucky if an indicated 100% would be near 90% of true capacity, same for the lower levels.
That isn't always true. Tesla's are known for 100% being actually 100%. However you are correct with most other EVs. Although according to mine and others observations using OBD2 readers, the Konas 100% is probably more around 97% and not 90%.

That is one of the reasons I use only 80% max on a daily basis leaving a big margin for the battery to feel happy. For road trips I charge up to 100%.
 

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That isn't always true. Tesla's are known for 100% being actually 100%. However you are correct with most other EVs. Although according to mine and others observations using OBD2 readers, the Konas 100% is probably more around 97% and not 90%.

That is one of the reasons I use only 80% max on a daily basis leaving a big margin for the battery to feel happy. For road trips I charge up to 100%.
But what are you reading with the OBD reader? The true battery capacity or just what the manufacturers have programmed into the vehicle system?
I know when we were developing the Focus EV (back in the 80’s) the batteries true capacity never got close to being 100% and the same was true for the depleted readings.

Its interesting and a bit disturbing that you say a Tesla when charged to an indicated 100% is a true 100% capacity, were did this information come from may I ask?

All information I have ever had is that Teslas charge up to 90% by default not 100%, apparently they can be fiddled with to charge to 100% but it is expressly warned against by the manufacture.
 

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Discussion Starter · #16 ·
And you could set the Zappi to ECO mode so that it only uses Solar as and when available.
We did indeed….turned off the normal boost charging (at our 5p per kw Octopus overnight) - got a healthy 32kw to fill it right up for free 😇👍

Plus….Latitude was an absolute blast of a festival, so very much win-win all round!
Final bonus….LFT tonight was negative 🤪. We will do a couple more over the next couple of days, but despite 40,000 people on site, the dry dusty outside was perfect for not spreading the coronavirus….as Professor Iain Buchan explained at one talkie thing we did!
 

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With an obd2 reader I actually get 2 SOC readings. The one that's displayed to the driver and a second one that's used by the BMS. Additionally, other geeks on this forum have done Amperage readings over drives to verify these readings and came up with very close numbers.

Tesla's seem to show a higher degradation than ex. the Kona. Which seems to be linked to the batteries being able to be charged to a higher SOC.
 
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