Timed charging on a granny lead for PHEV

[lesR]

I have a Mercedes CLA 250e (2024) and would like to start it charging at a set time and finish at a set time. Does the car have this capacity or is there a granny cable that I can purchase that will do this. Or does anyone have another suggestion that I could try (at reasonable cost).

The car can be set for a finish time but I believe this is only for setting the interior heating/cooling.

I'm new to PHEV and very impressed with the technology so far. So much so that I will be considering a full EV when it comes to changing the car. At present only a granny cable is possible but I may go for a wall charger once costs are looked into, as it is not a standard installation so may need to be done in stages.

[clockworks]

My 2021 XC40 PHEV uses an app to set the charge start and finish times.
Does your car not have a phone app?

[samoht]

I have a similar thing with my Citroen EV, which doesn't support setting a charge stop time.

I use a Tapo P105 smart plug
https://www.johnlewis.com/tp-link-tapo-p105-mini-w...
then plug the three-pin charger into it

The plug then has an app which lets you set a schedule for it, and it turns the power on and off accordingly.

I've been using this for a year with the three-pin charger running at 10A and it works perfectly.

[lesR]

Hi clockworks, samoht

The car does have an app but it is not that sophisticated, just shows if it's charging and how much.

The granny cable charges at 1.7 kW/h so the plug timer should work. I have 3 eve energy plugs rated at 13amp so I'll have a play this weekend and see what I can do.

Thanks for the information.

LesR

[clockworks]

I use a Tapo smart plug, as well as setting the charge schedule using the app.

In my case, the Tapo is just used as a "safety measure" if the app goes wrong (switching on just before the cheap rate starts, and before the app starts the charge), but it will do what you want - just check it for overheating on a regular basis.

If you get a Tapo P110, it includes energy use monitoring via the Tapo app. You can see how much electricity the car is using. Only costs a few quid more than the P105.

[samoht]

Tapo P110 page said:

EV charging is not supported since it typically requires higher power, and its charging current exceeds the rated current of the plug

https://www.tp-link.com/uk/home-networking/smart-p...

Tapo P105 page said:

Support Higher-Power Appliances – Schedule your kettle, coffee maker, and toaster to enjoy a "preset" breakfast

https://www.tp-link.com/uk/home-networking/smart-p...

Based on the above I went for the P105 specifically, although both are nominally 13A so it's not exactly clear. But if others are using the P110 happily then I guess any of them are fine.

[clockworks]

samoht said:

https://www.tp-link.com/uk/home-networking/smart-p...

Based on the above I went for the P105 specifically, although both are nominally 13A so it's not exactly clear. But if others are using the P110 happily then I guess any of them are fine.

That is a bit odd!

[durbster]

I was going to suggest a smart plug but I would be wary of the Tapo P110. They don't seem designed to last more than a couple of years but most worryingly, are prone to an issue where they fail in a state of permanently and continuously switching on and off:

More info here: https://community.tp-link.com/en/smart-home/forum/...

I don't know if damage can result from this but it's alarming. My last remaining Tapo plug failed a couple of days ago - I came into my office to hear a constant ticking and realised the plug had been turning a speaker on and off relentlessly for almost 48 hours.

The other common issue with them is the switch will appear to be working fine - you can toggle it on and off - but it doesn't actually cut the power.

I've got loads of smart plugs and the only ones to fail have been the Tapo ones, and I've experienced both the above issues, so beware!

Edited by durbster on Thursday 24th October 12:10

[clockworks]

durbster said:

I was going to suggest a smart plug but I would be wary of the Tapo P110. They don't seem designed to last more than a couple of years but most worryingly, are prone to an issue where they fail in a state of permanently and continuously switching on and off:

More info here: https://community.tp-link.com/en/smart-home/forum/...

I don't know if damage can result from this but it's alarming. My last remaining Tapo plug failed a couple of days ago - I came into my office to hear a constant ticking and realised the plug had been turning a speaker on and off relentlessly for almost 48 hours.

The other common issue with them is the switch will appear to be working fine - you can toggle it on and off - but it doesn't actually cut the power.

I've got loads of smart plugs and the only ones to fail have been the Tapo ones, and I've experienced both the above issues, so beware!

Edited by durbster on Thursday 24th October 12:10

What would you recommend as an alternative to Tapo?

I've got 6 of them, all controlled using Alexa and/or Tapo app schedules

[durbster]

clockworks said:

durbster said:

I was going to suggest a smart plug but I would be wary of the Tapo P110.

What would you recommend as an alternative to Tapo?

I've got 6 of them, all controlled using Alexa and/or Tapo app schedules

It was weird with TP-Link because they had two completely separate smart home brands at one point, Kasa and Tapo. Some of the Kasa plugs I had for years and they're all still going, which is why I thought the Tapo ones would be good. Those models are KP105, KP115 and HS100 but whether they correlate to the new Tapo devices under the skin, I don't know.

I moved away from WiFi to using Zigbee instead, but that needs a separate hub.

I've got Zigbee plugs from Aurora, Ikea, Sonoff and Innr and they've all been good (so far). The Sonoff ones occasionally drop off the network but just need a power cycle. The rest have been faultless.

[TheDeuce]

This:

https://alertelectrical.com/ener-j-smart-wifi-outd...

16a rated, will probably last longer than a smart plug. Putting this on the mains lead of your granny charger effectively converts it into a 'smart' granny charger, all weatherproof too.

[clockworks]

TheDeuce said:

This:

https://alertelectrical.com/ener-j-smart-wifi-outd...

16a rated, will probably last longer than a smart plug. Putting this on the mains lead of your granny charger effectively converts it into a 'smart' granny charger, all weatherproof too.

Thanks for the link.


Have you used these?

[TheDeuce]

clockworks said:

TheDeuce said:

This:

https://alertelectrical.com/ener-j-smart-wifi-outd...

16a rated, will probably last longer than a smart plug. Putting this on the mains lead of your granny charger effectively converts it into a 'smart' granny charger, all weatherproof too.

Thanks for the link.


Have you used these?

Not that exact type, but I use din rail mounted smart relays in automation control panels I build all the time, often to switch highly inductive loads, thousands of times - the actual relay component in the device I linked to will likely be the same sort of spec, just re-packaged into a weather proof solution.

I wouldn't be worried about it at all, it's only switching ~10a, when it's rated at 16a, probably tested to double that too. There are other similar products, I only suggested that one as it's sold by a UK registered business and their website states it is designed and tested to meet UK standards.

Just check you have decent wifi signal in the area you plan to use it

[clockworks]

TheDeuce said:

Not that exact type, but I use din rail mounted smart relays in automation control panels I build all the time, often to switch highly inductive loads, thousands of times - the actual relay component in the device I linked to will likely be the same sort of spec, just re-packaged into a weather proof solution.

I wouldn't be worried about it at all, it's only switching ~10a, when it's rated at 16a, probably tested to double that too. There are other similar products, I only suggested that one as it's sold by a UK registered business and their website states it is designed and tested to meet UK standards.

Just check you have decent wifi signal in the area you plan to use it

Ok. I was wondering more about the software, and the Alexa integration.
Some smart stuff that I've tried has been really poor with Alexa, which is why I've stuck with Tapo and Shelly.

[TheDeuce]

clockworks said:

TheDeuce said:

Not that exact type, but I use din rail mounted smart relays in automation control panels I build all the time, often to switch highly inductive loads, thousands of times - the actual relay component in the device I linked to will likely be the same sort of spec, just re-packaged into a weather proof solution.

I wouldn't be worried about it at all, it's only switching ~10a, when it's rated at 16a, probably tested to double that too. There are other similar products, I only suggested that one as it's sold by a UK registered business and their website states it is designed and tested to meet UK standards.

Just check you have decent wifi signal in the area you plan to use it

Ok. I was wondering more about the software, and the Alexa integration.
Some smart stuff that I've tried has been really poor with Alexa, which is why I've stuck with Tapo and Shelly.

I can't say for certain as I haven't used the brand before - although I must have at least ten different smart brand products with their own apps that all integrate with google home, which is what I use for home automation. Maybe check some of their product reviews to make sure people aren't struggling with Alexa integration.

[lesR]

Thanks for all the replies.The idea of some type of timer plug/system doing the job appeals to me

All the parts will be in the garage, so well protected from the elements and happy to use any app that is required (home mostly on HomeKit).

I'll have a happy weekend looking through all of your suggestions.

LesR

[Simon_GH]

Masterplug digital timers are 10 amp continuous rating.

[Dashnine]

TheDeuce said:

This:

https://alertelectrical.com/ener-j-smart-wifi-outd...

16a rated, will probably last longer than a smart plug. Putting this on the mains lead of your granny charger effectively converts it into a 'smart' granny charger, all weatherproof too.

I bought what looks like this (a WiFi, Alexa enabled box) already built into a cable with external weatherproof socket and RCD plug from Tough Leads.

[ashenfie]

It says it safe for indoor and out door use and talks about rain and snow, but It's only IP55 rated and therefore not suitable permanent outdoor use, it really needs to be IP65 or IP66.Further he device suggest useful for lighting and fountains, but nothing about EV charges. Finally and most worrying it states 16 amps and 2200w Hmm 16 amps at 230 volts is 3600w.

[TheDeuce]

ashenfie said:

It says it safe for indoor and out door use and talks about rain and snow, but It's only IP55 rated and therefore not suitable permanent outdoor use, it really needs to be IP65 or IP66.Further he device suggest useful for lighting and fountains, but nothing about EV charges. Finally and most worrying it states 16 amps and 2200w Hmm 16 amps at 230 volts is 3600w.

That's worrying if you're not used to how discrete components are rated for current protection purposes Vs continueous use, and in this instance, as it's a relay, switching capacity.

It also says it's ok for switching pumps, and a ~2000w pump will be far more brutal than switching a granny charger, due to the inrush current of a motor - also more likely to arc on the disconnect, which is what really shortens relay lifespan.