Power adapters for Tslim pump - too powerful?

Any technical folks on this forum that can answer this question?

The supplied power adapter for the Tslim pump is 5W.

I have one of these power banks which I think is at least 10W. Is this going to be a problem charging the pump?

How about other power adapters that are more than 5W, can the pump regulate how much power it consumes?

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Not particularly technical I’m afraid, but, if no one else is answering, I’d say you’re fine.
I’ve put the USB-A end of the Tandem cord into different power banks and power adapters including ones that plug into higher voltage English outlets. I think the Universal part of USB means that you don’t have to worry about the source. If it’s a USB-A port it’s going to universally put out an appropriate level of power.
But maybe one of the Tudiabetes engineers will respond. I think we have some.

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Technically it is up to the device to manage its power use. In reality engineering is all about compromise and sometimes when compromise meets reality unexpected things happen.

I dunno how good the pump’s power management is. In the US the TslimX2 comes with a 5V 1A 5W USB power supply. Looking at the power bank the port labelled with the single lightning bolt icon outputs the same so it could be fine.

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okay thank you both

Good Morning tedos:

A quick way to verify if it’s charging at a “normal” rate is to observe how quickly it charges to (100%) completion.

If the pace is substantially faster that normal, it will more than likely hurt the battery service life.

Just my two cents…


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I just got one that jumps the car and also powers devices. I was concerned about the Omnipod 5 controller. I detest rechargeable stuff but figured I was gonna need something for power failures. So hopefully it works safely.

Thanks, even with the original 5 w it charges pretty quickly. Will I really be able to see a difference?

There’s 2 different output ports on your charger, one of which is identical to Tandem’s 5v1amp= 5 watts. If you’re worried about it, just didn’t use the “faster” 5v2.1amps = 10 watts port.

For whatever it’s worth, 10 watts is still pretty weak sauce. Most phones are fast charging at 50-75ish watts or higher. My computer has a 180 watt charger. The 5 watt difference is pretty negligible in the electronics world. I’ve only ever used 10 watts to charge mine, because that’s what’s in the house. My husband has a pet peeve against 5w chargers and trashes them. Pretty sure the Tandem charger is still in the original box.

Ah thanks for pointing that out, i didn’t even realised there was two speed :sweat_smile:

Even so, do you know whether the tslim regulates the power input?

A charger’s rated capacity is the maximum output. The device being charged determines how much current it will accept.

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What most people call chargers are power supplies. They take the input power, usually AC at 120v, and convert it to the needed power usually DC at 5 or 12v. Your phone, pump, and other devices that take a charge will accept the incoming power, verify that is of the correct voltage, and then request up to the maximum amount of charge needed. That is why various devices can use a USB input for charging. As long as the input device has the same V and at least the A from the original device power supply you will be fine.

Others have accurately described the conditions above. Technically, it Ohm’s law. The source (power supply, adapter, battery, etc…) is responsible for the voltage and the load (pump, cell phone or almost all electronic devices…) is responsible for the current or Amps.

There is one other caveat here. If the load draws too much current the source should drop the voltage. This is know as current limit or overload protection.

In the case of our X2 pump, the pump won’t draw more than about 1/2 Amp no matter how big a 5V Power supply you use.

The other concern here is if the Voltage is too high, it can or will damage the load. The USB standard is 5V. As long as an adapter supplies 5V and at least the minimum amount of current it’s all good.

Batteries do not have current limiting protection. This is why lithium-ion batteries can catch on fire. Li-ion batteries, if not protected, can devope very large currents in either charge or discharge mode.

I use a 5V regulated battery that can charge cell phones. This gives me mobility when charging my pump.

And yes, I was a power systems engineer for almost 40 years. Sorry for man-splaining.



Thanks for explaining. Out of curiousity, is usb c also 5V? Usbc allows for fast charging on some devices

Tedos, this is where things get complicated.

Here is a link to Wikipedia on USB-C:

USB-C is really a digital and mechanical interface.

Of interest here is “fast charging” mode that many newer cell phones use with USB-C. This protocol allows more power to charge Li-ion batteries to charge faster. To do this, there is communication between the power supply / charger and the cell phone (typically).

When plugged in and connected, the supply delivers 5 V. The cell phone (load) asks for more power. More power is supplied by increasing the Voltage to 9V.

An increase in power is a result of increasing the Voltage while not increasing the current (VĂ—I =P). V goes up, current draw is the same, the power goes up.

So older tech like the X2 pump won’t ask for more current so the “smart” chargers won’t I crease the voltage beyond 5V.

So, all that said (or typed), yes USB-C will work at 5V.

I wish that the X2 pump was a USB-C connection. I hate micro-USB connectors. They are so hard to plug in. Hopefully the next gen (X3?) will have that.

Sorry if I went in too deep.