Question Does A True USB-C Power Splitter Exist?

[TheOtherOne]

Hi there,

I want a USB-C Power Splitter (two or multi output) and after doing lots of searching I simply can't find one. I've seen many "Splitters" that would split Audio and Power into each output or Audio / Data / Power but I haven't come across one that truly provides at least two Power outputs.

Bought three different brands off Amazon and despite their claims to have multiple Power outputs, they simply don't work. Only one of the socket provides Power for charging and the other one is always simply dead.

I have seen few USB-C "Cables" with multi sockets at the end but not interested in those haven't even bothered trying any. I want to be able to use different USB-C cables into one USB-C output socket with a proper Splitter mini cable or adapter connected in there first. Here's a couple of examples what I need but Power didn't work in both outputs.

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And Here's an example of One Cable with Multi Outputs that I don't want.

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Thanks!

 

[hotaru.hino]

If you're asking for a simple cable that can, for example, take one port of a battery bank and split it into two, this can't be safely done. Even if you did try this, you'll at best get nothing, at worst blow something up. To explain this:

From what I know of the USB spec, the baseline amount of power you're guaranteed to get is 5V and a small amount of amperage (around 1A). The device has to negotiate a higher power profile, either passively or through a data side-channel to talk to the charger. Also to send higher power, a higher voltage (such as 9V, 12V, 15V, or 20V) is used. Once both sides agree on which power profiles can be used, then the charger starts sending more power to the device.

The main issue here is, if you want to add multiple devices to one power output there's only allowed to be one device in charge of negotiating the power demands. If you have multiple devices demanding which power profiles they can use, it may cause the wrong kind of power to be delivered to another device. For instance, if you plug in a phone and a laptop in at the same time, the laptop may "win out" and tell the charger to deliver 20V. Except the phone is only capable of accepting up to 9V. Congrats, you just blew up your phone because the charger is now sending 20V to the phone. If the phone wins out in negotiation, it'll get 9V, but the laptop won't charge because the input voltage is too low.

If you want to "split" a USB-C port, you need to get something like a USB-C docking station. Though it may need a device connected to it before it actually delivers any power to the other ports.

 

[TheOtherOne]

If you're asking for a simple cable that can, for example, take one port of a battery bank and split it into two, this can't be safely done. Even if you did try this, you'll at best get nothing, at worst blow something up. To explain this:

From what I know of the USB spec, the baseline amount of power you're guaranteed to get is 5V and a small amount of amperage (around 1A). The device has to negotiate a higher power profile, either passively or through a data side-channel to talk to the charger. Also to send higher power, a higher voltage (such as 9V, 12V, 15V, or 20V) is used. Once both sides agree on which power profiles can be used, then the charger starts sending more power to the device.

The main issue here is, if you want to add multiple devices to one power output there's only allowed to be one device in charge of negotiating the power demands. If you have multiple devices demanding which power profiles they can use, it may cause the wrong kind of power to be delivered to another device. For instance, if you plug in a phone and a laptop in at the same time, the laptop may "win out" and tell the charger to deliver 20V. Except the phone is only capable of accepting up to 9V. Congrats, you just blew up your phone because the charger is now sending 20V to the phone. If the phone wins out in negotiation, it'll get 9V, but the laptop won't charge because the input voltage is too low.

If you want to "split" a USB-C port, you need to get something like a USB-C docking station. Though it may need a device connected to it before it actually delivers any power to the other ports.

Thanks for detailed explanation!

I want to use one USB-C (PD) port in the new car to charge multiple phones at the same time using different cables, simple as that.

In past, with USB 2 and 3, I was able to do that without any of these limitations. I know when both phones were plugged in, the charging speed would be slow but still they would get charged.

Any suggestions, other than using a Docking Station please? Since there's not enough room to add even a small Dock where the USB-C connector is in the car.

Also thinking, would it be possible and work if I use a USB-C to USB 3 connector and then use those old USB 3 Splitter to charge multiple phones or would it still cause any higher/lower power delivery issues as you mentioned above just because the main source is USB-C plug?

Thanks!

 

[hotaru.hino]

In past, with USB 2 and 3, I was able to do that without any of these limitations. I know when both phones were plugged in, the charging speed would be slow but still they would get charged.

The only reason why this worked is because there's only one voltage that can be supplied.

Any suggestions, other than using a Docking Station please? Since there's not enough room to add even a small Dock where the USB-C connector is in the car.

Also thinking, would it be possible and work if I use a USB-C to USB 3 connector and then use those old USB 3 Splitter to charge multiple phones or would it still cause any higher/lower power delivery issues as you mentioned above just because the main source is USB-C plug?

USB-C to Type-A may allow what you want since Type-A doesn't contain the communication side channel necessary to ask the charger for voltages higher than 5V. However you won't get any fast charging capabilities.

If your car has a 12V accessory port (AKA, the cigarette lighter port), I'd say get a charging adapter for that if you want to add more USB-C charging ports.

 

[TheOtherOne]

The only reason why this worked is because there's only one voltage that can be supplied.


USB-C to Type-A may allow what you want since Type-A doesn't contain the communication side channel necessary to ask the charger for voltages higher than 5V. However you won't get any fast charging capabilities.

If your car has a 12V accessory port (AKA, the cigarette lighter port), I'd say get a charging adapter for that if you want to add more USB-C charging ports.

Thanks. I will try to see if first option works, otherwise might go with a cigarette lighter multi charger. Was hoping to not add more stuff there but looks like there's no other option.

 

[hotaru.hino]

Thanks. I will try to see if first option works, otherwise might go with a cigarette lighter multi charger. Was hoping to not add more stuff there but looks like there's no other option.

Part of me wants to advise caution in doing this because of the unknown nature of the car charger outside of it being USB-C. If the devices connected to it draw more current than what was expected, this could lead to potentially dangerous situations.

Of course, you could either jury rig a 5A fuse on the cable or find one with it.