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Hi everyone,
Sorry if this isn't the place for it but I was hoping to ask you guys a question. My Mum has a BMW i3 and at school we were set a project to invent something. I thought with EVs set to become more popular and public charging posts mostly only having two sockets a socket extender would be a cool idea. So you plug in the device into one socket which gives three more sockets. Like a multi extension cord for a charging post. Mum thinks it could causing some feasibility issues and make you charge slower but I thick it's an intermediate solution.

Sorry I'll get to the point, has anyone come across this idea before or know of anyone else doing it? My research hasn't really turfed up anything.
 

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Nice idea, but the DC protocols for rapid charging are set up to stop this, mainly due to safety issues.

Apart from the fact a rapid charger at 50 kW spilt three ways would give each car only around 17 kW each.

There is a market for AC adaptors. See here:

Xavelec - Charging cables and adaptors for your Tesla EV UMC

However the need for these is going away with better rapid charger and destination charger coverage.
 

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Good idea and very doable for AC charging at least as a concept for a school project. For a product development quite a number of regulations are to be followed. To get familiar with the subject start to dig into some open source EVSE projects:

OpenEVSE/open_evse

You are also not the first attempting such splitter. Have a look:
J1772 Hydra



Hi everyone,
Sorry if this isn't the place for it but I was hoping to ask you guys a question. My Mum has a BMW i3 and at school we were set a project to invent something. I thought with EVs set to become more popular and public charging posts mostly only having two sockets a socket extender would be a cool idea. So you plug in the device into one socket which gives three more sockets. Like a multi extension cord for a charging post. Mum thinks it could causing some feasibility issues and make you charge slower but I thick it's an intermediate solution.

Sorry I'll get to the point, has anyone come across this idea before or know of anyone else doing it? My research hasn't really turfed up anything.
 

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In theory it could work....
But there are a few potential practical problems here.....

AC power problems: If you connect more than one car to one output the power would be divided so a 7kW post would become a slower charger.

Comms Issue: There are more connections in the charging connector that are used for car to charger communication, such as activating the locking mechanism on the car.

Safety: This would effectively be connecting three cars charging systems together and if a fault developed on one it could cause issues with the others.
 

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As mentioned above, it's not really feasible for DC rapid charging. That said Tesla kind of do the opposite for their big-rig trucks; they use multiple superchargers into one lead to charge their semi.

For AC charging, though, there are still a lot of practical and regulatory problems in reality.

There are products that kind of do what you suggest:

ClipperCreek Power Sharing Product Lets You Turn One Charging Station Into Two

As you can see from the way it is made, it's more complicated that a simple extension cord.

I hope someone with some more knowledge can come on and offer some further help. It's a good idea.
 

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Thanks everyone for your responses so far. You've given me a lot to get started with. I was thinking a 22kW AC charger would be the most suitable
Yes, you could split the 3 phases and give each car one phase. However, working on 3 phase electric is very dangerous, so as a school project it would probably need to be theoretical rather than practical.

Good luck with your project.
 
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