Tech Q

Tandem x2 users…had my pump plugged in to charge during a severe lightning storm…would that ever cause the outlet to like surge power and give pump a surge of electricity and make it give like a surge of insulin/give more insulin by ITSELF or malfunction in some way…am apprehensive to take insulin now?


While I do not profess to be an authority on such matters, just about anything electronic that is plugged into a wall outlet could get “fried” if there was a lightning strike to the electrical system very close to you. If that were to happen, however, I think that it is unlikely that the result would be an unexpected bolus delivery.

If I was really worried that my pump was acting up, I might go to the trouble of filling a new cartridge so that I could visually check that the pump seemed to be behaving normally.

I think that it may be wise to try to unplug sensitive electronics (laptops, phones, pumps, etc.) from outlets during electrical storms that are very near. If you need a charge at that time, I would suggest using a portable battery pack.

Note: I am not a professional in such matters. Also, I DO live in thunderstorm territory … but do not normally follow. my own recommendations.

I WOULD suggest consulting with Tandem Tech Support to see what their “official” policy is.

Stay safe!


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Thanks, will call tech support tom. before I change pump site again, bc would b nervous about bolusing with a full cartridge if there was an increase of bolus, who knows how much it could give ( I fill mine with 300 units!) But say tonight its low cartridge so would be less mistake if there was one yea? Probably sounds nuts this would happen but I have the worst luck and crazy things happen to me:/…btw, where r u located in thunderstorm territory? (U dont have to answer)

Your pump would not do that for certain.
It could be fried, damaged etc, but the worst case is it would stop working.
Your tandem pump has a motor and it’s programmed to move the number of times programmed to deliver insulin.
The actual pumping mechanism is in the cartridge.
So maybe 4 movements give a half a unit.
If you overloaded the pumps electronics, it would just stop.
Nothing would make it push more times, it just wouldn’t happen.

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@sweetgal88 I am, sort of, somewhat of an expert on electronic devices. I agree that a surge during charging probably would not cause a bolus dose. That is something you should check with Tandem support people to be sure. Usually what happens for a big surge is a device is destroyed. It may be obvious to the eye or not.

The Tandem x2 uses a USB port to charge. Two ways you can protect your pump from surges.

  1. get a surge protector designed to protect your devices. This is good for computers, audio/visual stuff, routers and wifi equipment. The come as outlets and power strips.

  2. if you really want to isolate you could get a USB battery pack that you charge alone, then use it to charge your pump. Tandem did a survey and a few users charge their pump in this manner.

Good luck, stay sweet personality wise, not blood wise.

I would like to add that I have no experience with insulin pumps, just a generic knowledge of electronics and electricity.

This is definitely not something tech support can help you with. This isn’t in their wheelhouse.

You’ll be happy to know that when you submit a device for FDA clearance, you have to pay for them to do a series of stress tests, to make sure the device doesn’t do anything life-threatening in extreme situations… Including electrocuting the device with a Tesla coil. Some of the tests are just absurd excuses to run up the bill. They actually dropped our photonics system, which only worked when plugged into a high-vintage dryer outlet, from a plane!

Seriously, though. There’s a series of stress tests within each category, which culminate with the absurd one. For electronics, they test for every feasible situation, including power surges, before the electrocute it entirely.

Devices aren’t expected to pass each and every single test. Early failures basically mean you have to redesign, but later extreme values get noted in the print material nobody reads.

If you look in the back of the user manual, there’s several pages worth of electrical tolerances and interferences. Basically the pump stops working as indicated in those specified extremes (maybe not catastrophically, but a function might seize until the exteme situation is resolved, such as communication issues)… But nothing as common as a power surge could make it deliver insulin. That would have gotten caught early and prompted a redesign.

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When I was young, and before T1D, I lived in Denver where afternoon thunderstorms are a common occurrence. Then I spent 50-ish years in CA, where thunderstorms are a rarity.

However, over the last 2-3 years, I’m in the process of moving to Santa Fe, NM. Frequent thunderstorms there as well. My pump doesn’t seem to care … but my dog sure hates thunderstorms.

Stay safe!

Note: for a battery-based charger, I have both a jumbo (20,000 mA-hr) and mini (5,000 mA-hr) Anker. I NEVER use an El Cheapo lithium battery pack!