The Braun ear and forehead thermometers and Vicks no-touch models here take 2 AA or 2 AAA batteries. The Braun and Vicks stick thermometers here take one coin cell, and Exergen’s TemporalScanner one 9-volt.
Who made it?
Which one?
The battery it takes
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When to change it
Most of these thermometers show a battery symbol when the battery runs low. Braun says the PRT2100’s symbol flashes continuously when it’s time, and that the TempleSwipe BST200 starts warning at 20% left and keeps working until it reaches 0%.
On Vicks’ stick thermometers the low battery sign is a down arrow: in the lower right of the V912’s display, and flashing at the top of the V966’s. Exergen’s TAT-2000 shows a blinking battery icon with the temperature while it still has power, and with two dashes once the battery is too low to take a reading.
Braun’s ThermoScan 3 takes one 3 volt lithium battery. For its code, read the old battery.
Which way the coin cell goes
Vicks says the coin cell goes in with the positive (+) side facing the battery cover in the V966, and facing the display side in the V912. Lift the old battery out with something that isn’t metal, Vicks adds.
Keep coin batteries away from children
The National Capital Poison Center says that if anyone swallows a battery, immediately call the 24-hour National Battery Ingestion Hotline at 1-800-498-8666 or your poison center at 1-800-222-1222. Don’t delay. Immediate treatment decreases severity.
Common questions
Are batteries included with a Braun ThermoScan 7+ Connect?
Yes, Braun says the ThermoScan 7+ Connect's 2 AA batteries come in the original packaging.
Why is my Vicks thermometer back in Fahrenheit after a battery change?
Vicks says its V966 and V912 thermometers return to Fahrenheit when the battery is replaced, and the steps to switch to Celsius are in their FAQs.
From Braun Healthcare’s and Vicks’ thermometer FAQs and Exergen’s TAT-2000 manual, all read on October 25, 2026. Checked against published data from Braun, National Capital Poison Center, Vicks and Exergen.
See all 5 sources
National Capital Poison Center, Button battery ingestion (poison.org/battery)
Braun Healthcare US, ThermoScan 5, 6, 7 and 7+ FAQs
Vicks thermometer FAQs (Helen of Troy): V966, V912, VNT200, VNT275
Exergen, TemporalScanner TAT-2000 Series manual (818503r10, PDF)
Battery sizes come from battery makers' datasheets and device makers' own manuals and help pages. Check your device's manual or the old battery before you buy. If anyone may have swallowed a battery, call the National Battery Ingestion Hotline at 1-800-498-8666 or your poison center at 1-800-222-1222 straight away.