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Discussion Starter · #1 ·
Hello. I have a level 2 charger question. I’ve been driving a PHEV for a number of years. At home I have a 7KW level 2 charger, but when out our holiday home use a level 1 charger. The holiday home is a static caravan with a 20A 240V supply for the whole van. I know in theory I could run a 3.6KW level 2 charger from this, but turning any high current devices on in the van such as the kettle would blow the breaker. Are there any level 2 chargers you can slightly manually turn down to 12A or 14A? Or even better any that can monitor the current use from the van and only take the available power? If not I’m stuck with level 1. Which is fine right now, but I’ve just ordered a full EV.
 

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If the holiday home charge point had a Viridian controller inside it, you can adjust the available current by changing the resistor.

If you fitted a Rolec, I have a version of the firmware that you can flash on to it that lets you set the current.

If you get one with a tethered lead, you might be able to change the resistor that pretends to be in the cable.

I’ll stop short of recommending using a granny charger.
 

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ID3 1st & e-Golf
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There are change points that can monitor the usage and adjust the charge. It isn't instant as it signals the car to reduce the current so if the breaker trips out quickly when the current goes over 20A that wouldn't work. I have the Zappi that will do this as well some others, Indra's charge point does and I think some of the EO chargers do. I'm sure there are plenty of others too. I would expect any that claim to work with solar panels are monitoring the incoming mains.

I'm fairly sure that some of portable chargers that connect to a commando socket have adjustable outputs but don't know any brands to recommend.
 

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so if the breaker trips out quickly when the current goes over 20A
Depends how much over 20A. A type B breaker to BS EN 60898 will operate after 5 minutes at 35A. Not suggesting you deliberately operate like that but there should be plenty of time for a chargepoint to regulate the max available current down and for the car to lower its demand.
 

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Tesla Model 3 LR AWD, Renault ZOE R135 ZE50 GTLine (Sold: R90 ZE40 i Dynamic Nav)
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I suspect that you are best to keep it simple and stick with a 10A portable EVSE. You will be adding at least 2kWh every hours, so 22kWh whilst parked for, say, 12 hours overnight, and more over a typical 24 hours on vacation, plugged in whenever you are on site. We've always found that is more than enough on site for local use and that we leave at the end our a break with close to 100% charge in a 50kWh ZOE. Even taking the full 20A available will only double your charging speed, at significant cost.

I would think carefully about the connections. Do you currently plug your level one charge point into a 13A plug into a socket in the van? If so, make sure that all the connections are low impedance, right through to the commando hookup. There's a big difference between running a kettle for 5 minutes and running a 10A charge point for 12 hours. I tend to connect via a high quality, weatherproof commando to 13A adaptor directly to the hookup commando socket and avoid any splitters whilst charging. Ideally, it might be good to have a second, switched commando socket installed in parallel to the one for the van, depending on site capacity and cost.

However, you need to consider the installation regulations and whether you would need some form of PEN fault detection, knowing you are doing a lot of EV charging. (Do a search for 'PEN fault detection device' - you could look at John Ward). If your site provided a good (TT) earth with an earthing rod or mat you should not need one. I'd consult a qualified electrician.
 

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Discussion Starter · #6 ·
Thanks all, think I’ll stick with the granny charger. Already have an outdoor 13A socket on its own protected circuit. Been using it for 4 years to charge a 10KW battery in my Passat GTE. Will just be running the charging circuit for much longer. If my calculations are correct the granny charger will add around 8-9 miles an hour to an Enyaq 80. Should equate to at least 100miles over night. Might take a day or two to fully top up the battery when we get there, but we typically don’t travel 100 miles a day when we are there.
 

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On balance that does sound best. Might be different if you were plugging into the home’s installation but on the basis of a dedicated socket it should be perfectly usable. As you say, as long as you get enough in for what you want to do each day and have enough by the end of your stay to get home again, you don’t get any benefit from upgrading.

I would think the earthing would be suitable because the risk of a touch potential between car and earth is the same as caravan and earth so should already be accounted for.
 

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Tesla Model 3 LR AWD 19" FSD; Renault Zoe Q210 22kWh
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I installed a 16A commando socket to the decking at my holiday home. We have a 32A main breaker. I ran this off of its own 20A circuit on the 'vans circuit board. Works great.

An example, I arrived with approx 10-15% over this last weekend in a Model 3 LR, took 16 hours to get back to 90%. I plugged in straight away at 8pm. If I remember rightly I was back to 90% by 10am ish. And for all of that I was either asleep or mooching about.
I am aware my maths above doesn't quite work out but all I know is I got back with a low-ish SOC, plugged in at 8pm and was complete by 10am the next day. Car takes about 1 hour for every 5%.

We just make sure we are always plugged in whenever we are back. Gives us plenty of electrons for all of our bits and bobs down there and we are always ready to go when we have to leave.
 
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