Thoughts on Commando + Ohme as Home Charging Option

[Noel83]

Hi all,
So reviewing all the options for home charging the 'Ohme' (Homepage - Ohme) has caught my eye (on offer from Octopus for £199 instead of £399).

My M3P is coming through Evezy meaning I don't have the normal order confirmation docs to be able to get the charger installed ahead of time. So I've been looking into options then I got an email from Octopus with the Ohme.

So my thinking is I could get a local electrician to fit a commando socket (awaiting prices but assuming around £200) get the Ohme and end result is same smart charging capability as a fitted charging point, similar total cost as if I had the grant (most chargers seem to be £350-400 after grant) and the benefit that I can take the Ohme with me or sell it if/when we move house in the future.

Amazon sell a little £15 plastic 'dock' for the charge connector sorting that bit too.

So any thoughts? Am I missing something? Am I way out of whack with the likely cost for the fitting of a commando socket?

Cheers

Noel

 

[MrBadger]

If you were going to charge a car sat outside from a commando you would be subject to the same RCD/earthrod considerations as a Mode 3 wall socket.

PS does ohme turn commando into type 2? I thought it was effectively a type 2-type 2 cable to turn a non smart untethered Mode 3 wall connector into a smart wall connector.

 

[NorfolkMustard]

Yeah, Ohme have cables for type2, commando and even 3-pin. Or, they also do one as a wall charger (I.e. permanent mains wired )

Products - Ohme

 

[elecTED]

I’m not sure what the benefit and saving would be of a purchasing a smart cable (Ohme) + having a commando socket fitted.

Looks like you may end up paying more than a grant funded tethered smart wall charger (Pod-Point/Rolec ~£360).

Unless you’re thinking of moving home next week, I wouldn’t worry about losing £160 - (the extra cost of a convenient tethered smart wall charger unit with 3 years warranty compared to £200 for the commando socket install).

 

[Glan gluaisne]

It's hard to see where any cost saving would be. The commando would need to be hard wired in exactly the same way as a charge point, as its primary purpose is as an electric vehicle charge point. so the installation cost will be the same as that for a charge point, but with no grant allowance.

The Ohme is an OK solution, but then it would be cheaper to just buy the 32A commando lead for the Tesla supplied charge point. I believe the 32 A lead is less than £40, and the portable charge point comes free with the car.

 

[Noel83]

Aah some good learnings here thanks guys. My understanding (possibly wrong) was that a commando socket when paired with an Ohme lead would give me full domestic charging speed at a similar cost to having a tethered point with a grant but without me having to get a grant.

Reason being my timing challenges as mentioned above.

Interesting ref the 32A commando lead and Tesla charge point/lead that's free with the car, so that'd give me full speed charging as a pod point/rolec but at a lower cost?

Ideally I want a tethered solution and part of me wants it all to be as smart as possible for integration with Octopus tariff without me having to faff with Tesla on screen charging settings every time (I won't have access to Tesla app due to it being through Evezy).

I'll get an electrician quote locally and see what that comes in at.

 

[Glan gluaisne]

Aah some good learnings here thanks guys. My understanding (possibly wrong) was that a commando socket when paired with an Ohme lead would give me full domestic charging speed at a similar cost to having a tethered point with a grant but without me having to get a grant.

Reason being my timing challenges as mentioned above.

Interesting ref the 32A commando lead and Tesla charge point/lead that's free with the car, so that'd give me full speed charging as a pod point/rolec but at a lower cost?

Ideally I want a tethered solution and part of me wants it all to be as smart as possible for integration with Octopus tariff without me having to faff with Tesla on screen charging settings every time (I won't have access to Tesla app due to it being through Evezy).

I'll get an electrician quote locally and see what that comes in at.

Yes, a 32 A commando, installed as an electric vehicle charge point (so in accordance with Section 722 of BS7671:2018) coupled with the UMC that comes with the car, plus the optional 32 A commando adapter lead, will charge the car at 32 A OK.

I believe that the 32 A adapter lead is less than £40 from Tesla as an accessory, and it just plugs in to the charge point in the same way as the 16 A commando and 13 A leads that come with the car.

 

[WannabeOwner]

a commando socket when paired with an Ohme lead would give me full domestic charging speed at a similar cost to having a tethered point with a grant

From discussion here a while back the upshot was:

If you install a Commando socket and use the UMC that comes with the car you may save some money on installation, but you are of course putting wear and tear on your (expensive) UMC cable, and if you need to take the UMC cable with you then you have to coil it up in the rain etc. or risk not having it with you when you need it in an emergency. If you install Commando and "buy" a spare UMC-type cable then it works out about same price as Tethered Wall Charger

A Commando socket needs the same electrical gubbins as a Wall Charger - some wall charger include that (so cost more to buy, but less additional cost during installation). Sure, you can fit a Commando socket WITHOUT any of that, but that would definitely be a bad idea and put you at risk, and a Sparky who knows that you are planning to charge a car from Commando should not cut those costs / corners.

Putting a Commando socket in at e.g. Relies and then using your UMC for the "occasional charging" there may be a good choice, but for regular charging (e.g. "at home") it is better to get a wall charger.

If suitable wall charger is OLEV approved then that is usually cheaper, but OLEV chargers are typically a bit more expensive than non-OLEV ones, so OLEV route is likely to only be £2-300 cheaper.

Tesla charge point/lead that's free with the car,

This is a 16 AMP Commando plug (nowadays on UMC Gen 2, it used to be 32AMP Commando on Gen 1), so you would also have to buy the 32AMP UMC Commando adaptor (from memory around £35)

 

[Noel83]

Perfect thanks all, any idea how much a spare Tesla UMC is here in the UK?

 

[Glan gluaisne]

Perfect thanks all, any idea how much a spare Tesla UMC is here in the UK?

Why would you want a spare one? The car comes with one in a bag in the boot, so all you need is the 32 A commando extension lead.

I've just roughly costed the installation of a 32 A commando, complying with Section 722 of BS7671:2018, as an EV charge connection, and it looks like the cost would be about £70 for a 32 A commando, fitted to a caravan hookup box, with the necessary circuit protection, around £50 for cables, earth rod, etc (assuming a fairly short cable run) and maybe another £40 for installation stuff at the consumer unit end. Add in half a day's labour at about £150 and it should cost around £300 to maybe £320 installed.

The question is really whether you could get a budget charge point installed for less than this, allowing for the OLEV grant. I suspect it would be a close run thing as some are reporting installation costs of around £300. A proper charge point would be simpler to use, and mean no wear and tear on the UMC from the car, either.

 

[Noel83]

@Jeremy Harris Because I wouldn't want to be rummaging in the boot every time and wouldn't want to leave it at home.

My original idea was could I get a tethered solution using Ohme (or now UMC) for a similar price to a fixed point after OLEV grant without needing the evidence that OLEV requires.

Looks like a local installer is happy to take my deposit invoice from Evezy as enough for a full install so as suggested above a proper point is likely to be the way forwards.

Love the activity on these forums, thanks for all the suggestions everyone

 

[Keeper]

I considered an external commando socket with internal trip and this cable supplied by Metron. The UMC part is built into the Type 2 plug. Means no boxes lying in the rain. I elected for a Rolec Smart eventually but it looked a good idea. Not cheap but comparable with net wall charge point installation cost but no 3 year guarantee.



https://eauto.si/metron-shop/wp-content/uploads/Metron_PC03_PC04_PC05_User_Manual_rev.4_WEB.pdf

 

[Glan gluaisne]

I considered an external commando socket with internal trip and this cable supplied by Metron. The UMC part is built into the Type 2 plug. Means no boxes lying in the rain. I elected for a Rolec Smart eventually but it looked a good idea. Not cheap but comparable with net wall charge point installation cost but no 3 year guarantee.

View attachment 476837

https://eauto.si/metron-shop/wp-content/uploads/Metron_PC03_PC04_PC05_User_Manual_rev.4_WEB.pdf

There's a significant safety flaw with a cable like that, in that the cable is always live when plugged in to the supply, irrespective of whether it's plugged in to the vehicle or not. A proper charge cable is always dead when not plugged in to the cable, as there is a DP isolator built in the charge point, that kills the power to the cable as soon as it is unlatched from the vehicle.

Having said that, I did use one like this that I made up, which charged at 10 A, and was built in to a Type 1 connector. I fitted a plug-type RCD to this long cable (around 30m) and used it to charge my Prius plug-in when away on holiday, if staying somewhere with no charging facilities. I accepted the risk of running an always-live cable outside, on the basis that it was really no different to running an extension lead, or electric mower lead, but it's not really a very good solution, IMHO.

 

[Keeper]

There's a significant safety flaw with a cable like that, in that the cable is always live when plugged in to the supply, irrespective of whether it's plugged in to the vehicle or not. A proper charge cable is always dead when not plugged in to the cable, as there is a DP isolator built in the charge point, that kills the power to the cable as soon as it is unlatched from the vehicle.

Having said that, I did use one like this that I made up, which charged at 10 A, and was built in to a Type 1 connector. I fitted a plug-type RCD to this long cable (around 30m) and used it to charge my Prius plug-in when away on holiday, if staying somewhere with no charging facilities. I accepted the risk of running an always-live cable outside, on the basis that it was really no different to running an extension lead, or electric mower lead, but it's not really a very good solution, IMHO.

It does come down to discipline, tidiness and common sense when using, handling and storing any power cable. All cables are live when the car is charging. When not charging - put safely away. The commando socket that I had it mind had an isolating rotating switch to power off when not in use. I use a cable tidy with a Type 2 plastic holster riveted to it for when my untethered cable is not in use.

 

[WannabeOwner]

The commando socket that I had it mind had an isolating rotating switch to power off when not in use.

But it can be left turns on and disconnected from the car - in that case a basic cable will still be live I think?.

Exposed end of a UMC cable would not be live in that situation.

I'm not disciplined enough, but would also worry that some well meaning soul disconnects the car, unwittingly stows the cable neatly and young children are then inquisitive ...

how much a spare Tesla UMC is here in the UK?

Commando Socket (plus earthing rod or whatever else you need) PLUS a UMC cable is the same price as a Tethered Wall Charger.

You'd be better off fitting a tethered wall charger ...

Commando + UMC cable (the one that came with the car) is a good solution for places where you only charge on occasion.

I had a look on eBay and completed, sold, auctions for Tesla UMC have gone for around £350-£375

 

[Glan gluaisne]

Safety really comes down to ensuring anyone using anything is adequately protected, irrespective of their level of understanding of any risk.

I'll accept risk levels with electrical stuff that I wouldn't expect others to, and will, if I have to, work on a live installation. I try hard never to do this, but there are times when it's essential.

By the same token I'd not let someone else use, or be near, my home made Type 1 charge cable, with it's EVSE circuitry inside the car end connector, because the cable was always live when plugged in. It didn't bother me unduly, but I wouldn't have lent that cable to someone, or allowed anyone other than me to use it.

I'd also not suggest that someone use such a cable on a public forum, just because there's a risk that someone might choose to use one without realising that doing so posed some risk.

 

[Keeper]

Safety really comes down to ensuring anyone using anything is adequately protected, irrespective of their level of understanding of any risk.

I'll accept risk levels with electrical stuff that I wouldn't expect others to, and will, if I have to, work on a live installation. I try hard never to do this, but there are times when it's essential.

By the same token I'd not let someone else use, or be near, my home made Type 1 charge cable, with it's EVSE circuitry inside the car end connector, because the cable was always live when plugged in. It didn't bother me unduly, but I wouldn't have lent that cable to someone, or allowed anyone other than me to use it.

I'd also not suggest that someone use such a cable on a public forum, just because there's a risk that someone might choose to use one without realising that doing so posed some risk.

Just trying to be helpful. I didn't go down this route but it is an alternative.

 

[elecTED]

Perfect thanks all, any idea how much a spare Tesla UMC is here in the UK?

£366 from Tesla UK

Is your best friend a 3 pin plug?

 

[Glan gluaisne]

Just trying to be helpful. I didn't go down this route but it is an alternative.

It is very helpful, for sure. I'm just a bit sensitive to some stuff that might have a slightly higher risk for those using it, that's all. I'd use something like this, and did for several years. There's always the issue of liability, though, and the sort of thing that some may choose to do without realising the possible risks. The main one with these cables that stay live is that an unmated type 1 or type 2 connector has no real weather protection, so could present a risk to someone foolish enough to drop the connector in a bucket of water.

I may be overly sensitive on safety related stuff. Much of that comes from seeing a lot of really appalling DIY electrical work over the years. How more people aren't killed by their own stupidity, and, perhaps, ignorance, I just don't know. Back when I was a small boy, one of my earliest memories is of my mother (who was the very practical on in our home; my father never even learned to drive a car) teaching me to wire a plug. and not only drumming into me "red on the right" but also making sure the earth lead was left a little longer than the others, and that the cable grip was firmly securing the outer insulation layer.

 

[Artiste]

A friend of mine can’t get the £500 OLEV grant so was looking for cheaper alternatives to buying a wall charger. Her local electrician charges £40 for the first hour and £20 for every subsequent hour. She bought this socket (I think it’s this one):

Industrial RCD Socket IP67 240V 32A 30ma 2P+E Switched

Total materials were £110 and electrician was £60. Rather than using the UMC supplied with the car she bought her own - that was the most expensive bit. But she’s now charging at 32A and is a happy bunny.