Home charger dropping from 7KW down to 1.4KW

[clockworks]

Anyone else having this issue:

My Kia EV3 has recently started dropping the charge rate down to the minimum 1.4KW. It happens after the car has been charging for an hour or so.
If the charging slot ends, and another one starts at some point later on, it resumes at 7KW.

I'm using a Zappi charger and Octopus Intelligent Go. Charger is integrated with Octopus, no schedules set in the Zappi or Kia apps, just the schedules sent to the Zappi by the Octopus app.


This seems to be fairly common issue with Kia and Hyundai EVs.

[t_rifles]

My Zappi down rates when it overheats in full sun during the summer. Perhaps your is also getting hot. There is an indicator on the display and internal temperature in the menus somewhere.

[clockworks]

I only charge during the cheap Intelligent Go periods, so mostly late evening or overnight..

I did ask MyEnergi about the problem, and they said I should check the PWM reading, see if it drops below 50%. Above 52%, the charger is offering 7KW, so a lower rate means the car is rejecting it.

Unfortunately you have to check while it's running at the 1.4KW rate - tricky at 2am.

It's a shame that the Zappi doesn't store log files, or report any unusual events to the Zappi app.

[P675]

The charging slots are not always at full chat. In my ohme app it says the speed of the slot, sometimes you get a slot every hour with different speeds. If the charger gets you to 100% in the morning there's nothing to worry about.

[dmsims]

P675 said:

The charging slots are not always at full chat. In my ohme app it says the speed of the slot, sometimes you get a slot every hour with different speeds. If the charger gets you to 100% in the morning there's nothing to worry about.

Yep - IOG has always varied the speed

[clockworks]

dmsims said:

P675 said:

The charging slots are not always at full chat. In my ohme app it says the speed of the slot, sometimes you get a slot every hour with different speeds. If the charger gets you to 100% in the morning there's nothing to worry about.

Yep - IOG has always varied the speed

Maybe I should try a daytime "boost" charge, see if it stays at 7KW?

If it's Octopus making the rate drop, that's fine.
Thing is, this is all over the UK Kia forums. People having issues with the the Niro EV too.

[RotorRambler]

Looks like you’re onto something a bit odd, ChatGpt says:-

Yeah, you’re definitely not alone — this is a known issue cropping up for quite a few Kia and Hyundai EV owners, especially when using Octopus Intelligent (formerly Intelligent Octopus Go) with a Zappi charger. The behavior you’re describing — where charging starts at full 7kW, then drops to around 1.4kW after an hour — seems to be part of a compatibility quirk between the vehicle’s onboard charger logic and how Octopus/Zappi schedule and manage charge sessions.

Here’s what’s commonly going on:

What Might Be Causing It:
• Kia/Hyundai BMS logic: These EVs sometimes throttle charging power if they detect any perceived “irregularity” in the charging session. For example, if the Zappi stops and starts a session (as Octopus may instruct), the car may default to low current to “play it safe.”
• Octopus Intelligent API control: Octopus sends charge windows to the Zappi, which acts on them without the car’s direct awareness. If there’s a mismatch in timing or how the car interprets these sessions, it may not ramp back up unless a new session fully starts.
• Zappi charger behavior: The Zappi can sometimes resume charging in a way that the car doesn’t treat as a clean “start,” especially without physical reconnection or if the handshake isn’t perfect.

Things That Might Help:
1. Force-stop the charge session in the Kia app and restart it — some users report this forces the car to renegotiate charging at full rate.
2. Try using a different charge mode on the Zappi (like ECO+ vs. FAST) to see if it makes a difference in session handshaking.
3. Check for firmware updates on both the Zappi and your vehicle — some of these issues have been partially addressed in more recent updates.
4. Reach out to Octopus support — they may be able to tweak your Intelligent Go settings or confirm if there’s a bug or known behavior in play.

It’s frustrating because everything is technically working — it’s just not working together very well. Until Kia/Hyundai and charger manufacturers iron this out better, it’s often down to trial-and-error or workarounds.

[cliffords]

I wonder if in a few years it will be a common discussion.
I did not get a full charge last night as it's not windy, or very cold etc .
The shape of things to come perhaps.

[clockworks]

There have been reports of the same problem with Ohme chargers on Intelligent Go.

Kia have released an over the air update for the ICCU (charge control unit), which got installed in my car last week. Too soon to know if it has resolved my issues, but others have reported no change.

I have tried manually stopping the charge using the Kia app, unplugging, and plugging back in. The charge did indeed restart at 7KW, but dropped back to 1.4KW after a few minutes.

[sixor8]

I'd be very annoyed if I'd paid our for a charger and it had happened to me.

I get about 2.1 kW (gross) from a 3-pin plug. I've coped with it for 13 months now, and managed to carry out over 95% of my home charging at the cheap rate overnight.

[Knock_knock]

clockworks said:

There have been reports of the same problem with Ohme chargers on Intelligent Go.

Kia have released an over the air update for the ICCU (charge control unit), which got installed in my car last week. Too soon to know if it has resolved my issues, but others have reported no change.

I have tried manually stopping the charge using the Kia app, unplugging, and plugging back in. The charge did indeed restart at 7KW, but dropped back to 1.4KW after a few minutes.

But are you getting your target charge by your target time?

I've got mine set to add 80% by 7am, and it's always on target on time, regardless of what "strange" mix of low and high power slots I'm getting.

This is on Ohme, but since I don't think Kia vehicles are supported on IOG I assume that it's the same on Zappi.

[clockworks]

Knock_knock said:

But are you getting your target charge by your target time?

I've got mine set to add 80% by 7am, and it's always on target on time, regardless of what "strange" mix of low and high power slots I'm getting.

This is on Ohme, but since I don't think Kia vehicles are supported on IOG I assume that it's the same on Zappi.

Sometimes yes, sometimes no.

I normally charge when it drops to 60%. I've got the AC charging limit set to 90% in the Kia app.
I set the Octopus app to add 10% more than I need, to account for charging losses, with a completion time of 8am.

If Octopus gives me multiple short slots, starting early evening, it'll reach the requested amount.
If I don't get any extra slots at all, and just a couple of slots during the standard period, it won't reach the 90% cutoff set by the car. It spends too long at 1.4KW.

Zappi is integrated with Octopus.

Because I only normally do 100 miles a week, it's not a big issue. I'd like to get to the bottom of it though.
I could understand it being Octopus setting a lower charge, but it's always 100% at the start of a slot, and the absolute bare minimum if it decides to drop later on. Nothing in between. From what I can make out, AC charging just can't be done at less than 1.4KW.

If it's the car, I want Kia to resolve it.

The reason for my post was to see if others are having the same problem, to find a pattern. If only Kia/Hyundai cars have the problem, then there's no point chasing MyEnergi or Octopus.

Kia/Hyundai have had AC charging issues on previous models, but these seem to have mostly been complete failures requiring replacement ICCU modules, or faults with the 12v systems.
This seems to be a new, EV3, issue. Most likely a software/firmware problem.

If non-Kia owners have the same problems with IOG and charger integration, that would shift the blame, and I could just accept it as "that's how it is with IOG, but I'm saving money".

[dmsims]

What the point in setting anything in the car ?

IOG (if integrated at the charger level) knows nothing about the car

ETA I guess it could be a useful experiment to integrate the car instead

[Knock_knock]

clockworks said:

Sometimes yes, sometimes no.

I normally charge when it drops to 60%. I've got the AC charging limit set to 90% in the Kia app.
I set the Octopus app to add 10% more than I need, to account for charging losses, with a completion time of 8am.

My strategy is to request an 80% charge (ie: 80% of the 64kWh battery) from Ohme, and the Kia is set to stop at 80%. I set a departure/ready time in Ohme of 7am. I charge every other day, and it always works perfectly this way. Maybe give this approach a go?

clockworks said:

If Octopus gives me multiple short slots, starting early evening, it'll reach the requested amount.
If I don't get any extra slots at all, and just a couple of slots during the standard period, it won't reach the 90% cutoff set by the car. It spends too long at 1.4KW.

I wonder if you're trying to out-think it???

You should always get the 6 hours overnight slot, regardless. And I've rarely seen that below c. 7kW. Which should comfortably provide what you need.

clockworks said:

I could understand it being Octopus setting a lower charge, but it's always 100% at the start of a slot, and the absolute bare minimum if it decides to drop later on. Nothing in between. From what I can make out, AC charging just can't be done at less than 1.4KW.

Behaviour I have observed is that if you plug in at, say, 4:24pm, you will usually get full charging until 4.30pm, at which point the rules kick in. So you might get the next half hour slot at a lower rate. I have seen 1.4kW quite often during afternoon and early evening slots. And 3.4kW sometimes. Same thing will happen if you plug in at, say 4:33pm - until 5pm I would expect full charging.

IOG works in 30 minute slots; that's the limit of it's granularity.

clockworks said:

The reason for my post was to see if others are having the same problem, to find a pattern. If only Kia/Hyundai cars have the problem, then there's no point chasing MyEnergi or Octopus.

We had the same behaviour from a Renault before it was changed (for another Kia). A friends Tesla received the same behaviour when plugged in (I don't tell Ohme there's a different car). But I don't really consider what it does anymore - it works so I leave it alone...

[Knock_knock]

dmsims said:

What the point in setting anything in the car ?

IOG (if integrated at the charger level) knows nothing about the car

ETA I guess it could be a useful experiment to integrate the car instead

Kia was supported by IOG but it tended to crush the 12v battery by polling the SOC too often, so presently they're not available for integration. Zappi and Ohme chargers are (possibly others too), and as you say they know nothing of the vehicle that is attached to them. The only setting that should be made on the car is the stop point - 80% in my case.

[clockworks]

Knock_knock said:

dmsims said:

What the point in setting anything in the car ?

IOG (if integrated at the charger level) knows nothing about the car

ETA I guess it could be a useful experiment to integrate the car instead

Kia was supported by IOG but it tended to crush the 12v battery by polling the SOC too often, so presently they're not available for integration. Zappi and Ohme chargers are (possibly others too), and as you say they know nothing of the vehicle that is attached to them. The only setting that should be made on the car is the stop point - 80% in my case.

The car setting is just to tell the charger to stop when the battery hits a certain percentage. Most people say it's not a good idea to charge above 80% - unless you are going on a long journey and need the range. AC and DC max charge limits are set in the Kia app.

Charger integration means that Octopus can't "see" the car, but it does know the battery size, because you tell it during setup. Octopus knows that I have a Kia EV3, with a 78KWh (usable) battery. If I request a 50% charge, it knows it should be adding 39-ish KWh.

Of course, if I was to plug in a different car, it would still try and add the percentage based on the EV3 battery capacity.

[clockworks]

Knock_knock said:

clockworks said:

Sometimes yes, sometimes no.

I normally charge when it drops to 60%. I've got the AC charging limit set to 90% in the Kia app.
I set the Octopus app to add 10% more than I need, to account for charging losses, with a completion time of 8am.

My strategy is to request an 80% charge (ie: 80% of the 64kWh battery) from Ohme, and the Kia is set to stop at 80%. I set a departure/ready time in Ohme of 7am. I charge every other day, and it always works perfectly this way. Maybe give this approach a go?

clockworks said:

If Octopus gives me multiple short slots, starting early evening, it'll reach the requested amount.
If I don't get any extra slots at all, and just a couple of slots during the standard period, it won't reach the 90% cutoff set by the car. It spends too long at 1.4KW.

I wonder if you're trying to out-think it???

You should always get the 6 hours overnight slot, regardless. And I've rarely seen that below c. 7kW. Which should comfortably provide what you need.

clockworks said:

I could understand it being Octopus setting a lower charge, but it's always 100% at the start of a slot, and the absolute bare minimum if it decides to drop later on. Nothing in between. From what I can make out, AC charging just can't be done at less than 1.4KW.

Behaviour I have observed is that if you plug in at, say, 4:24pm, you will usually get full charging until 4.30pm, at which point the rules kick in. So you might get the next half hour slot at a lower rate. I have seen 1.4kW quite often during afternoon and early evening slots. And 3.4kW sometimes. Same thing will happen if you plug in at, say 4:33pm - until 5pm I would expect full charging.

IOG works in 30 minute slots; that's the limit of it's granularity.

clockworks said:

The reason for my post was to see if others are having the same problem, to find a pattern. If only Kia/Hyundai cars have the problem, then there's no point chasing MyEnergi or Octopus.

We had the same behaviour from a Renault before it was changed (for another Kia). A friends Tesla received the same behaviour when plugged in (I don't tell Ohme there's a different car). But I don't really consider what it does anymore - it works so I leave it alone...

I can see exactly what's going on using Home Assistant. I've got a Shelly clamp energy monitor on the supply to the charger.

It clearly draws 7KW for a period, then may drop down to 1.4KW.
If it drops down to 1.4KW, it will stay at that rate until the slot ends.
When the next slot starts, it will be back at 7KW again.

If the gap between slots is short, it will only stay at 7KW for a few minutes. If the gap is longer, it will stay at 7KW for an hour or so.

I've even seen it do a 1 hour slot at 7KW for 55 minutes, drop down to 1.4KW for a couple of minutes, then stop charging.

These are overnight "guaranteed" slots, as well as the bonus evening slots - same behaviour.

And no, I rarely get given a continuous 6 hour overnight slot. It's nearly always broken down into several shorter slots. It obviously knows that the 30% or 40% charge that I requested won't take 6 hours at 7KW, so it breaks up the 6 hours.

[Sheepshanks]

Daughter has been putting typically 40% into her Mk 2 Kona every weeknight using IOG and an Ohme Pro and, touch wood, it’s worked fine since she got it in early Dec 24.

She doesn’t have a limit set on the car ( so it’s at 100%) but aims to get to around 90% so she’d still be able to do her commute if a charge failed. She plugs it in on arrival home at 7PM and tells it to be ready at 7AM. It quite often does some slots during the evening.

If it was charging at a lower rate would that be obvious to her in the Octopus app?

[Knock_knock]

clockworks said:

I can see exactly what's going on using Home Assistant. I've got a Shelly clamp energy monitor on the supply to the charger.

It clearly draws 7KW for a period, then may drop down to 1.4KW.
If it drops down to 1.4KW, it will stay at that rate until the slot ends.
When the next slot starts, it will be back at 7KW again.

If the gap between slots is short, it will only stay at 7KW for a few minutes. If the gap is longer, it will stay at 7KW for an hour or so.

I've even seen it do a 1 hour slot at 7KW for 55 minutes, drop down to 1.4KW for a couple of minutes, then stop charging.

These are overnight "guaranteed" slots, as well as the bonus evening slots - same behaviour.

And no, I rarely get given a continuous 6 hour overnight slot. It's nearly always broken down into several shorter slots. It obviously knows that the 30% or 40% charge that I requested won't take 6 hours at 7KW, so it breaks up the 6 hours.

That's really weird behaviour.

If you take the car to a L2 (AC 7kW) charger how does it behave there? If it's dropping down from 7kW on a public charger then I would suggest a fault within the car. If not, I wonder if something odd is going on with your Zappi.

Maybe worth trying a different cable, just in case there's a fault with yours?

Bump your charge requirement up to 80% and see if that helps? Maybe I've never seen this problem because I'm demanding more charge.

[clockworks]

Knock_knock said:

That's really weird behaviour.

If you take the car to a L2 (AC 7kW) charger how does it behave there? If it's dropping down from 7kW on a public charger then I would suggest a fault within the car. If not, I wonder if something odd is going on with your Zappi.

Maybe worth trying a different cable, just in case there's a fault with yours?

Bump your charge requirement up to 80% and see if that helps? Maybe I've never seen this problem because I'm demanding more charge.

Trying a different charger is on the cards, booked in at the dealer next week for them to investigate.
So far, I've only ever charged at home.

Because I don't do many miles, it doesn't need charging very often.

Increasing the requested charge is a good idea, as it might force Octopus to offer me longer, continuous, slots