Are there any UK 3-pin granny chargers that include a built in timer?

[Nujec]

Ideally I'd like to find a 3-pin charger for our second EV that has a built-in timer so that we can restrict charging to off-peak hours. Does such a thing exist? If we convert the socket to a 16A 'commando' socket, are there any chargers that include a timer? If not perhaps we're better off spending a bit more for a proper second charge point.

The excellent toughleads.co.uk sell a high current timer switch extension lead but it feels like it would be better if it was built into the 3-pin charger itself. If the 3-pin charger plug has a temperature sensor it seems safer if the plug is directly plugged into the socket rather via any extension cables, however well made they are.

The Tesla allows the charge start to be scheduled but not the charge finish time so we constantly have to guess the charge limit to stop charging within off-peak hours.

To pre-empt any obvious safety questions about the hazards of 'granny' charging
- The socket used is a brand new waterproof exterior socket installed at the same time and from the same new consumer unit as our charge point using the same grade of cabling as the charge point (designed to allow converting it to a second charge point later). The socket has never got warm in use in my experience.
- Our Zappi charge point is setup up to monitor the whole household supply and lower the Zappi current if the whole house load is too high.
- All fittings are waterproof and used under cover (a car port).
- I only ever charge at 10A (the maximum the Tesla UMC delivers)

I noticed quite a few 3-pin chargers advertised as 13A (I always use 10A). Is a sustained 13A actually safe from a well-installed household socket? Everything I read suggests it isn't.

 

[GRiLLA]

Are both cars Tesla? If the only requirement is to stop charging after Go why not use an app you can schedule like TeslaFi to send a stop charging command.

 

[Nujec]

That's a good point. I'll check that out.

 

[VNKR]

Ohme makes a smart granny charger afaik.

 

[WannabeOwner]

That's a good point. I'll check that out.

if you create a TeslaFi account with a referral code you'll get a month trial instead of two weeks. If you haven't got a better offer you can use my nickname here, or get one from this thread.

FWIW my schedule includes:

5 mins after Off Peak - Start charging (you'd expect the car to do this ... but ... in case it has been changed / disabled etc.)
10 mins after Off Peak - Set Charging Amps = 32 (Annoying if you've turned it down for some reason and forgotten to put it back up!)
5 mins before end of Off Peak - Stop charging - this is the key one that Tesla doesn't do natively

If you have an early departure for work (and that is early enough that pre-conditioning from Grid is still in Of Peak - e.g. Ecconomy-7) then I do:

A few minutes after start of Off Peak reduce Charge Limit to 80%
1 hour before end of Off Peak Reinstate charge limit to 90% (or whatever is your norm) - so that car will be / resume charging in the hour before end of off peak (warm battery in Winter etc)

Assumption: Charging adds 10% to the car in one hour; adjust to taste

For regular commuters (set these to week days only, beware they will also run on Bank Holidays)

One hour before work departure: Wake Up
20 minutes before departure: Start HVAC (Or using a Climate Preset e.g. Summer / Winter)
10 minutes after normal departure: Stop HVAC - in case you haven't actually left!

18:00 Charge Limit Reminder : When charge limit above 91% [tick/configure the appropriate EMail etc. checkbox] (in case you've left it at 100%)
18:00 Plug in reminder: When battery below 50% [tick/configure the appropriate EMail etc. checkbox] (in case you've forgotten to plug it in)

 

[WannabeOwner]

If we convert the socket to a 16A 'commando' socket, are there any chargers that include a timer?

I expect you could use something like an immersion timer - sparky will have something suitable.

However, Commando, "for an EV", has requirements for Sparky which increase the cost and you may decide it is near enough to cost of Wall Charger that you do that. Saves wear and tear on UMC, and you can have the UMC in the car and thus if ever you needed it in an emergency you'd have it with you - and not have to coil it up wet whenever it rained ...

 

[devonian]

I have one of these feeding a dedicated socket for a granny charger Shelly Pro 1PM | Shelly Store UK | Smart Home Automation this allows you to time and monitor current usage I have a hypervolt charger that is used most of the time but as we have 2 EV's I use the timed granny charger occasionally when needed and to keep the Tesla topped up when in the garage for any longer period of time

 

[Nujec]

I have one of these feeding a dedicated socket for a granny charger Shelly Pro 1PM | Shelly Store UK | Smart Home Automation this allows you to time and monitor current usage I have a hypervolt charger that is used most of the time but as we have 2 EV's I use the timed granny charger occasionally when needed and to keep the Tesla topped up when in the garage for any longer period of time

Thanks, that's a pretty neat solution. Does that fit entirely into a UK consumer unit as a replacement for the normal circuit breaker MCB thing? Is it a fairly straight forward installation?

 

[devonian]

it is a standard size din raill fitting so goes into a consumer unit, but not a a replacement for an MCB as this is still needed for over current protection it is as well as an MCB so you need to have a spare slot. installation is very straight forward, depends upon your wiring of course, in my case I have the dedicated socket wired directly to the consumer unit

 

[Moon Dweller]

Or in a similar vein to the Shelley as previously mentioned, a simple DIN timer might suit… British General Fortress 16A 2-Pole Digital 1-Channel Consumer Unit Timer Module - Screwfix

 

[btc1k]

All very complicated solutions.

My tesla granny charger has a Tapo fitted to it, £20. Turns it into a timer and app controlled too.

Tapo

 

[Moon Dweller]

All very complicated solutions.

My tesla granny charger has a Tapo fitted to it, £20. Turns it into a timer and app controlled too.

Tapo

I very much doubt that you would be able to fit a Tapo into an outdoor waterproof socket such as OP plans to use.

 

[Nujec]

All very complicated solutions.

My tesla granny charger has a Tapo fitted to it, £20. Turns it into a timer and app controlled too.

Tapo

Yeah, they're good, I've got similar plugs elsewhere in the house. Do they manage 10A for hours without getting warm at all? They're probably not designed for heavy duty loads over long periods.

The main drawback for me is that it would be too bulky and prevent the exterior socket cover closing.

 

[Nick77]

You can buy timers that plug into the power socket and have a 3 pin socket on them to plug your device into. They're about a fiver.

My mum uses one to time when her washing machine comes on. I assume it'd work the same.

 

[thewishy]

Do be careful what you buy. A standard timer switch will not be designed to run 10a for hours on end. Ditto a lot of the smart stuff. Best case, you'll kill the relays quite quickly. Worst case, fire.

Look for something which is intended for immersion units

 

[WannabeOwner]

Or in a similar vein to the Shelley as previously mentioned, a simple DIN timer might suit… British General Fortress 16A 2-Pole Digital 1-Channel Consumer Unit Timer Module - Screwfix

I have one of those (or similar) for my immersion. Fiddly to set the time etc. but other than that its been fine for years <KnockOnWood>