Charging two EVs at home

[c2mike]

The initial message was deleted from this topic on 28 December 2022 at 11:17

[MOBB]

My house is 100a and I had 2 EO Mini chargers fitted next to each other, tiny little units

One is set at 32a and the other is 16a

We use both at the same time overnight, or just charge one in the day if one car needs it. No issues so far.

Works perfectly for us

Edited by MOBB on Saturday 13th June 19:14

[mcm87]

A Zappi might be able to be configured this way. It’s designed to maximise solar usage but I’m sure I read it can also be used in this sort of way.

[PKLD]

A few charge point models offer load limiting but Tesla ones don’t dynamic change the load depending on what the house is using (last time I checked) but they will share the rate of charging between them e.g. if one finishes the other gets the ‘full’ power rate

Also worth remembering that certain models don’t qualify for the OLEV grants and you’ll get 2 x £350 if you have 2 EVs or PHEVs at home

Lastly there is a new dual outlet charger that has just been approved by OLEV (these are common for commercial installations but frustratingly haven’t been available for domestic use)

Hope that’s some help for now but happy to answer anything else ;-)

[Frimley111R]

Chances are high that you won't need to charge the cars at the same time and so 1 will do. As said, you'll get 2 charging at half the quickest rate because 7.2kw chargers are limited by the power your home has. Or you'll get one charging first and then the charger switching over to the second one when finished.

[robbieduncan]

No idea if these are good or not: saw them on twitter a couple of days back. But Easee chargers can load balance (wirelessly) with each other. So you can have up to 3 on a single home circuit. https://easee-international.com/uk/

[blueacid]

Forgive the ask, but with the OP having a 100A feed to their house, why can't they have two 32A chargers?
With 32A x 2 being 64A that leaves 36A otherwise. If you've got all-electric heating, cooking, hot water, then yes I can understand there being the need to manage this, but in general would such a thing not be possible?

[Frimley111R]

blueacid said:

Forgive the ask, but with the OP having a 100A feed to their house, why can't they have two 32A chargers?
With 32A x 2 being 64A that leaves 36A otherwise. If you've got all-electric heating, cooking, hot water, then yes I can understand there being the need to manage this, but in general would such a thing not be possible?

Basically because 36a is not enough for a house. Don't forget about lights, big TV, appliances etc it all adds up. It may be ok some of the time but it has to be ok anytime.

[robbieduncan]

Frimley111R said:

Basically because 36a is not enough for a house. Don't forget about lights, big TV, appliances etc it all adds up. It may be ok some of the time but it has to be ok anytime.

But chargers with some sort of dynamic load balancing might be ok? Detect total load and reduce charger output as house load ramps up. So full power overnight when there is little load but lower power during the day. Not sure if such a product/set of products exists. I think the ones I linked to just balance between themselves (so you give them say 40A between then but no measurement of the whole house demand)

[LimaDelta]

robbieduncan said:

But chargers with some sort of dynamic load balancing might be ok? Detect total load and reduce charger output as house load ramps up. So full power overnight when there is little load but lower power during the day. Not sure if such a product/set of products exists. I think the ones I linked to just balance between themselves (so you give them say 40A between then but no measurement of the whole house demand)

Ours does that. A little more expensive but given we have a) an old house and b) lots of electrical consumers it was pretty much essential.

[Frimley111R]

robbieduncan said:

Frimley111R said:

Basically because 36a is not enough for a house. Don't forget about lights, big TV, appliances etc it all adds up. It may be ok some of the time but it has to be ok anytime.

But chargers with some sort of dynamic load balancing might be ok? Detect total load and reduce charger output as house load ramps up. So full power overnight when there is little load but lower power during the day. Not sure if such a product/set of products exists. I think the ones I linked to just balance between themselves (so you give them say 40A between then but no measurement of the whole house demand)

Yes, that's correct. Not all have this and it does require some additional intelligence in the charger and further connections.

[Spunagain]

2 Tesla wall chargers can be set up to load balance between them when sharing a current limited feed.
Video here
See page 27 of the manual here for the wiring

Edited by Spunagain on Wednesday 17th June 15:14

[mikeiow]

c2mike said:

Anybody got any suggestions for a dual home EV charger? I have a Tesla and my wife wants an EV too.
I'm limited to around 32A total as my house is single phase 100A supply.
I would like to be able to optimise the available 32A, depending on whether one or two cars are charging. By that, I mean that I can charge one car at 32A and two cars can share with 16A each.
I believe Tesla Wall Chargers support this when two of them are connected up correctly. Are there any alternatives out there?

It is an interesting idea......but.....

Are there many times when you use the full range of the Tesla in one day *and* your wife would do the same with hers?

I ask because (as Frimley111R suggested), I would be surprised you would need to charge both.

& if so.....would the 7kWh feeding in be able to fill both up overnight?
Our KonaEV would theoretically take about 9 hours to "fill up from near empty". I would guess similar for a Tesla?

We are considering whether our next car swap (likely 12-18 months out) might be my diesel for another EV.....but for our use cases, I sorely doubt we would ever need more than the one charge-point.

[SWoll]

We ran 2 EV's (i3 120ah and Model 3 P) for 4 months and 8k miles alternating charging with a single 3 pin plug charger and still didn't have to charge every night.

You'd have to be doing some serious combined mileage to 'need' 2 x 7kW chargers at home.

[MOBB]

mikeiow said:

c2mike said:

Anybody got any suggestions for a dual home EV charger? I have a Tesla and my wife wants an EV too.
I'm limited to around 32A total as my house is single phase 100A supply.
I would like to be able to optimise the available 32A, depending on whether one or two cars are charging. By that, I mean that I can charge one car at 32A and two cars can share with 16A each.
I believe Tesla Wall Chargers support this when two of them are connected up correctly. Are there any alternatives out there?

It is an interesting idea......but.....

Are there many times when you use the full range of the Tesla in one day *and* your wife would do the same with hers?

I ask because (as Frimley111R suggested), I would be surprised you would need to charge both.

& if so.....would the 7kWh feeding in be able to fill both up overnight?
Our KonaEV would theoretically take about 9 hours to "fill up from near empty". I would guess similar for a Tesla?

We are considering whether our next car swap (likely 12-18 months out) might be my diesel for another EV.....but for our use cases, I sorely doubt we would ever need more than the one charge-point.

As I posted above, we have 2 chargers. With hindsight 1 would have been plenty.