Discussions on using Ohme charger with the ZS EV

[JodyS21]

This started off being discussed on another post (Which charger? Experiences?).
I thought I'd start one specifically for the Ohme charger, so we can share info and tips.

Preamble:
The Ohme charger isn't geared up for what I want, which I think is probably a pretty normal requirement.
Charge during off-peak and then let it carry on afterwards for however long it wants to - to allow for balancing & if the 4 hour off-peak charge isn't enough to get the car to 100%.
I've got Octopus Go - 12:30-4:30 a 4 hour off-peak period.
(There's nothing in the app to manage/allow the balance charge)

@Mikes has shared a work around he's come up with which is very good.

Which charger? Experiences?

Loving my new car and Octopus Go is on its way in a week or so, so the question now is which charger to get. Favourite at the moment is the Ohme, as I'm concerned i may need the earth rod for the others. Has anybody had experience with the Ohme, or preferences for other chargers?

www.mgevs.com

From constant adjustments to find out what the app does, I've identified the following:
4 hours will give a maximum of 91miles/56%
6 hours 10mins will give a maximum of 141miles/86%
If I configure up a schedule which only allows a 4 hour off-peak charge and tell it I want too many miles added, it shows an error/warning every time I plug in and adjusts the schedule itself, so I wanted to know the most miles I could get within the period without it complaining.

I now have the following schedules setup for Ohme to work happily:
Tariff 00:30-04:30 5p / 04:30-10:30 14.29p / 10:30-00:30 14.30p (the fake 04:30-10:30 is the bodge to get it to work as wanted)
Limit charging to a maximum of 14.29p (restricts charging to 00:30- 10:30)
On days when I need 100%, to charge until 6:40 (this is when I leave for work) and add 141miles.
On all other days, I charge until 4:30 (to just use up the off-peak period) and add 91miles.

This now sorts out most of my issues:
It forces Ohme to not start charging until my off-peak rate at 00:30 starts.
I will always maximise the use of my off-peak rate - as it will always use this period first to allow the car to charge before potentially letting it do more afterwards.
If the car doesn't need much charge, it should finish its main charge within the set time schedule and allow some time to do a balance.
What is doesn't do:
I can't actually guarantee I will automatically have 100% on the days that I want it. If the car had less 14% it won't reach 100% by the time I need it. But this is the best that is automatically possible without having an API. If it's really low I'll just have to manually start the charge to max at around 10pm.
It doesn't guarantee I get a full balance done automatically once a week (or month etc).

I have not yet checked how accurate the Ohme's mileage to add actually is.
Have they taken AC-DC losses into account.
Have they just taken 163 miles wltp divided by 42.5kWh capacity.

 

[AdeB]

This started off being discussed on another post (Which charger? Experiences?).
I thought I'd start one specifically for the Ohme charger, so we can share info and tips.

Preamble:
The Ohme charger isn't geared up for what I want, which I think is probably a pretty normal requirement.
Charge during off-peak and then let it carry on afterwards for however long it wants to - to allow for balancing & if the 4 hour off-peak charge isn't enough to get the car to 100%.
I've got Octopus Go - 12:30-4:30 a 4 hour off-peak period.
(There's nothing in the app to manage/allow the balance charge)

@Mikes has shared a work around he's come up with which is very good.

Which charger? Experiences?

Loving my new car and Octopus Go is on its way in a week or so, so the question now is which charger to get. Favourite at the moment is the Ohme, as I'm concerned i may need the earth rod for the others. Has anybody had experience with the Ohme, or preferences for other chargers?

www.mgevs.com

From constant adjustments to find out what the app does, I've identified the following:
4 hours will give a maximum of 91miles/56%
6 hours 10mins will give a maximum of 141miles/86%
If I configure up a schedule which only allows a 4 hour off-peak charge and tell it I want too many miles added, it shows an error/warning every time I plug in and adjusts the schedule itself, so I wanted to know the most miles I could get within the period without it complaining.

I now have the following schedules setup for Ohme to work happily:
Tariff 00:30-04:30 5p / 04:30-10:30 14.29p / 10:30-00:30 14.30p (the fake 04:30-10:30 is the bodge to get it to work as wanted)
Limit charging to a maximum of 14.29p (restricts charging to 00:30- 10:30)
On days when I need 100%, to charge until 6:40 (this is when I leave for work) and add 141miles.
On all other days, I charge until 4:30 (to just use up the off-peak period) and add 91miles.

This now sorts out most of my issues:
It forces Ohme to not start charging until my off-peak rate at 00:30 starts.
I will always maximise the use of my off-peak rate - as it will always use this period first to allow the car to charge before potentially letting it do more afterwards.
If the car doesn't need much charge, it should finish its main charge within the set time schedule and allow some time to do a balance.
What is doesn't do:
I can't actually guarantee I will automatically have 100% on the days that I want it. If the car had less 14% it won't reach 100% by the time I need it. But this is the best that is automatically possible without having an API. If it's really low I'll just have to manually start the charge to max at around 10pm.
It doesn't guarantee I get a full balance done automatically once a week (or month etc).

I have not yet checked how accurate the Ohme's mileage to add actually is.
Have they taken AC-DC losses into account.
Have they just taken 163 miles wltp divided by 42.5kWh capacity.

 

[AdeB]

I don't know why the forum's posted an empty reply from me above! Can a mod delete it, please?

Jody, I replied to your earlier post. I think you're trying to overcomplicate things with the Ohme (and perhaps not helped by their customer service - I've had only one occasion to contact them but wasn't overly impressed with the reply!).

The Ohme is set up to use cheaper rates of energy first. So if you have Octopus Go, it will work out what charge it can add using your cheaper rate first, before 'topping up' with standard rate to reach your desired mileage/charge level.

If you limit the rate to 5p or less, then - as you have found out - you'll always add only a maximum charge of 91 miles (87 miles in my case). But if you don't limit the rate, and allow it to do its own thing, then if you're getting home in the early evening and plugging in, your car should be fully charged by 06.30, with the charger having worked out that most of the charging should be done on the cheap rate (i.e. it won't start charging when you plug it in, but might well start the charge before 00.30 so that it still has enough time to fully charge).

As for balancing, as I understand it from the owner's manual (but perhaps others can confirm) then the car itself decides when it needs balancing and will flag up an instruction accordingly. I don't believe it will balance on every charge, once full charge has been reached.

 

[notdodgy]

I don't know why the forum's posted an empty reply from me above! Can a mod delete it, please?

Jody, I replied to your earlier post. I think you're trying to overcomplicate things with the Ohme (and perhaps not helped by their customer service - I've had only one occasion to contact them but wasn't overly impressed with the reply!).

The Ohme is set up to use cheaper rates of energy first. So if you have Octopus Go, it will work out what charge it can add using your cheaper rate first, before 'topping up' with standard rate to reach your desired mileage/charge level.

If you limit the rate to 5p or less, then - as you have found out - you'll always add only a maximum charge of 91 miles (87 miles in my case). But if you don't limit the rate, and allow it to do its own thing, then if you're getting home in the early evening and plugging in, your car should be fully charged by 06.30, with the charger having worked out that most of the charging should be done on the cheap rate (i.e. it won't start charging when you plug it in, but might well start the charge before 00.30 so that it still has enough time to fully charge).

As for balancing, as I understand it from the owner's manual (but perhaps others can confirm) then the car itself decides when it needs balancing and will flag up an instruction accordingly. I don't believe it will balance on every charge, once full charge has been reached.

You can over-ride the current schedule to max charging if you need to do a balance charge.
If it needs to do a substantial charge first, then wait until it's nearly charge and set max charge again to extend the time.

Because our cars do not have an API, it's down to guesswork with the Ohme.

I am not on Octopus (Gas prices significantly higher than current provider), so not had chance to see how the off peak feature works or whether amount of miles to add or charge cost takes priority.

 

[JodyS21]

I don't know why the forum's posted an empty reply from me above! Can a mod delete it, please?

Jody, I replied to your earlier post. I think you're trying to overcomplicate things with the Ohme (and perhaps not helped by their customer service - I've had only one occasion to contact them but wasn't overly impressed with the reply!).

The Ohme is set up to use cheaper rates of energy first. So if you have Octopus Go, it will work out what charge it can add using your cheaper rate first, before 'topping up' with standard rate to reach your desired mileage/charge level.

If you limit the rate to 5p or less, then - as you have found out - you'll always add only a maximum charge of 91 miles (87 miles in my case). But if you don't limit the rate, and allow it to do its own thing, then if you're getting home in the early evening and plugging in, your car should be fully charged by 06.30, with the charger having worked out that most of the charging should be done on the cheap rate (i.e. it won't start charging when you plug it in, but might well start the charge before 00.30 so that it still has enough time to fully charge).

As for balancing, as I understand it from the owner's manual (but perhaps others can confirm) then the car itself decides when it needs balancing and will flag up an instruction accordingly. I don't believe it will balance on every charge, once full charge has been reached.

Unfortunately it does not work successfully that way, because the Ohme has no idea how much is already left in the car.

It assumes the car is empty and will calculate the schedule based on that worst case scenario.
Therefore if my schedule says to add 163miles it will always think it needs to add that much and, if the rate is the same before the off-peak period as afterwards, if will start charging before the off-peak period starts. In most circumstances the car will then not get charged making full use of the off-peak period.

On some days we will plug the car in, needing it for 6:30am, with maybe 75% battery remaining. This can all easily be charged during the off-peak period.
Some days we will plug the car in, needing it for 6:30am, with only 20 miles left in the battery.


Balancing isn't like that. The car does a balance from my experience at least 1/2 of the time. We've always been charging to 100% until now (got Ohme & Octopus Go) using granny charger & I can see that it is not very often it does not do any balancing (it can sometimes only balance for an hour, sometimes 4 hours).

 

[JodyS21]

You can over-ride the current schedule to max charging if you need to do a balance charge.
If it needs to do a substantial charge first, then wait until it's nearly charge and set max charge again to extend the time.

Because our cars do not have an API, it's down to guesswork with the Ohme.

I am not on Octopus (Gas prices significantly higher than current provider), so not had chance to see how the off peak feature works or whether amount of miles to add or charge cost takes priority.

You can just have electric with Octopus and keep gas with another supplier

We had 10 miles left in the car by the time of plugging it in on Monday evening, needed 100% for 6:30am, so on that occasion I just set it to Max Charging at 10pm.
It's kind of okay my for me (other than a faff) as I'm on top of what's going on, but for my wife she just wants to plug it in and let it sort it out for her.

 

[notdodgy]

You can just have electric with Octopus and keep gas with another supplier

We had 10 miles left in the car by the time of plugging it in on Monday evening, needed 100% for 6:30am, so on that occasion I just set it to Max Charging at 10pm.
It's kind of okay my for me (other than a faff) as I'm on top of what's going on, but for my wife she just wants to plug it in and let it sort it out for her.

My current supplier doesn't list a gas only option.
None of the other providers can beat my current deal at the moment.
I don't think I would get enough off peak use to gain significant savings.

If I had a daily commute it would make sense, but I am getting away with a single 20-30kw charge a week depending on whether I can plug in free at a supermarket.

If the washing machine / dryer are in use I just use a granny charger.
(I picked up a decent second had one from a charity shop).

 

[JodyS21]

I'm using Apple iOS Ohme App.
Anyone else noticed if you look at the app in the morning, so after it's charged but not unplugged, the amount of kWh under Battery->Energy Charged is wrong (mine showed 49.3kWh this morning)?
After I unplugged and looked at the App afterwards it showed the more correct figure of 32.5kWh Battery->Energy Charged (which matched the 32.47kWh shown on the Ohme lcd)

 

[JodyS21]

Figured out how many kWh the Ohme uses in it's calculation for miles added now (as you can't say add x kWh but only say add x miles).

For every mile you say you want added, it will add 0.3kWh, plus a base amount of 0.6kWh.
50miles = 15.6kWh
100miles = 30.5kWh
163miles = 49.5kWh

So it looks like it's adding 15-20% to allow for the AC-DC losses.

 

[JodyS21]

I'm not sure why I'm bothering to give Ohme lots of information on what is not correct on their app, their support just doesn't listen and just gives pointless replies.

One thing I did get from their support is the following nugget of information:
"We get the car's specs from MG. For the ZS EV 2019, we have a max charge rate of 7.2kWh, battery capacity of 44.5kWh, and max range of 263km."
So this must be what they base their calculations on.


Latest thing I've learnt is that the graph that their app (iOS) produces is not at all representative of what has happened. Info below if anyone is interested.

From my cctv:
Car started charging at 00:30.
Finished and switched to balancing at 03:12
Was unplugged (don't know if balance had finished) at 06:37
App says 18.6kWh added.

My schedule was set to add 140miles by 6:40.
From the graph I've roughly worked out that each time unit on the graph is 20mins.
The graph shows that 56 miles were consistently added from 00:30 until 06:37, I know this is not true as it was only charging at full speed from 00:30-03:12 and then was only balancing for the rest - so drawing a tiny amount of power.

When it was unplugged at 06:37, it has calculated that from that point at full charge speed, it would take until 10:15 to charge it with the rest of the scheduled miles (another 84m), which is in theory about right (at 0.3kWh per mile = 25.2kWh @ 7kWh = 3h36).

So, in producing the graph:
They have taken the future potential finish time (10:15) and the time it started charging (00:30) and plotted a straight line between those points.
They have then looked at the time it was unplugged (06:37) on the X axis and where that meets the drawn line, at that point on the Y axis just labelled it as the miles that they think have been added when it was unplugged (+56miles).
Thus producing a graph that totally mis-represents what has happened.

 

[BarryH]

My daughter had her Ohme Charger installed yesterday and last night I had a slew of questions on how to get it set up for a delay and to be sure she had a charge for this morning. She is (like me) on OctopusGo but said it started charging as soon as the car was plugged in. She could only find a way of setting the charge end time which I guess is the time to have "car charged by". I've not seen the app and installing it doesn't help because unless it is linked to a specific charger you cant get past the App trying to sell you a charger. Can the Ohme be set to charge from 00:30 am to 4:30 am?

 

[JodyS21]

My daughter had her Ohme Charger installed yesterday and last night I had a slew of questions on how to get it set up for a delay and to be sure she had a charge for this morning. She is (like me) on OctopusGo but said it started charging as soon as the car was plugged in. She could only find a way of setting the charge end time which I guess is the time to have "car charged by". I've not seen the app and installing it doesn't help because unless it is linked to a specific charger you cant get past the App trying to sell you a charger. Can the Ohme be set to charge from 00:30 am to 4:30 am?

You can bodge it to just charge between 00:30-4:30.....

If you've got the tariff setup correctly in the app to have the 5p rate only during that time period, you can set the maximum amount you want to pay to charge to 5p, then it will ONLY charge during that period.
The problem you'll have is trying to setup a schedule that doesn't cause the app to pop up warnings about not being able to charge in time etc.
Best thing to do, is set it to be charged by 04:30, then keep adjusting the miles to be added so that you've got the highest amount it can be without it complaining about not being able to charge in time - See the screenshot of mine (may need to take 1 or 2 miles off still - different days is seems to allow slightly more/less miles!)

FYI, if the car is plugged in more than 10 hours before the scheduled start time, it will start a trickle charge before the 10 hours is up - as the car goes to sleep after 10 hours and then cannot be woke up to start charging.
I'm not sure, but I think it does a 6Amp trickle charge. Shame it doesn't do something like 1Amp, to minimise energy usage when you don't want it to.

 

[rjb70stoke]

Got mine fitted Friday. Charged perfectly as per schedule, so far so good.

 

[Jomarkh]

I have my Ohme set up and working ok but the display is always lit and the temperature seems high 35°. Is this normal and can they be updated?

 

[JodyS21]

I have my Ohme set up and working ok but the display is always lit and the temperature seems high 35°. Is this normal and can they be updated?

I don't think that temperature is particularly unusual, I've seen mine is often a lot higher than ambient temperature, when charging I've seen mine at 45c (and it was cold outside). It must be the electronic inside generating temp.
Display is always on too, although outside it doesn't show up much on mine.