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Isotronic marten deterrent 12 V or battery

Updated: 22 October 2026

You already have an electronic Isotronic unit in mind for mice or rats on a UK drive, and the open question is the supply. An Isotronic marten deterrent 12 V or battery decision is whether model 78440's ignition cut-out matches a car you drive and can wire, or whether cells are safer because you will not touch the loom. A short lead, tiny cover screws, or a module left on a stored car are the ways this goes wrong. Captured prices in the [Isotronic marten deterrent comparison](/hub/pest-control/isotronic-marten-deterrent) run from £25.61 to £45.28. The belt has no supply, so it is outside this choice. We did not measure current on a car. A qualifying purchase can earn a commission at no extra cost to you.

You already have an electronic Isotronic unit in mind for mice or rats on a UK drive, and the open question is the supply.

Our top picks

Isotronic Isotronic 78440 12 V car ultrasonic

Best overall

Isotronic Isotronic 78440 12 V car ultrasonic
8.2/10about £25.61
View offer
Isotronic Isotronic 78580 LED ultrasonic dual power

Alternative

Isotronic Isotronic 78580 LED ultrasonic dual power
7.6/10about £32.45
View offer
Isotronic Isotronic twin-pack vibration ultrasonic

Alternative

Isotronic Isotronic twin-pack vibration ultrasonic
7.6/10about £45.28
View offer
On this page
  1. 1.When the car battery is the supply
  2. 2.When cells are the supply
  3. 3.Dual power on the 78580
  4. 4.Which supply matches the car

When the car battery is the supply

Use the car battery when the unit is the Isotronic 78440 and the car is one you actually drive. The grey lead goes to terminal 15 so the module can run with the ignition off. The sheet quotes about 5 mA and about 0.6 W. That is the only current figure in this set, and it is not a promise the car will start after a month, because you still disconnect the module if the car will sit. Other scarers print cut-offs around 11.5 V, 11.8 V, 10.7 V or 9.2 V. None of those voltages is printed for these five listings. Do not paste them onto 78440. On a CAN-bus car the grey lead goes to the fuse of terminal 15. If you cannot see that fuse, use the how to fit an Isotronic marten deterrent in a car page and stop. A boot battery is a poor match for a lead of about 100 cm. The best Isotronic marten deterrent page treats 78440 as the parked-car pick only with that wiring.

When cells are the supply

Cells are the better supply when you will not touch the loom, or when the battery is in the boot. The vibration LED, at £31.18, states a cut-out. The twin pack, at £45.28, uses six AAA cells, claims about eight months, and states a sensor that switches on about 60 seconds after the car is still. Neither listing prints a milliamp draw. The eight-month line is the pair's listing claim, not a winter measurement, and it is a different sentence from the 78580 manual. A UK review of the pair says only one unit worked and the seller refunded half. If a unit arrives dead, the Consumer Rights Act 2015 is the route for a refund or a replacement. On the vibration LED, a UK review says the screws are too small for anything but a jeweller-sized driver. Do not force them. Another review says mice were still visiting nightly. The listing marks that box as not electric while the bullets describe a cut-out.
Isotronic Isotronic 78440 12 V car ultrasonic

Testsieger

Isotronic Isotronic 78440 12 V car ultrasonic
8.2/10about £25.61
View offer

Dual power on the 78580

Choose model 78580, at £32.45, when you want four AA cells or a car-battery lead and you will live with the split. The UK bullets cite 12–24 kHz, a flash about every 60 seconds and 40 m². They do not mention a vibration sensor. A separate manual describes that cut-out, up to eight months on alkaline AA cells, and about 60 m² indoors. Keep those lines apart. There is still no milliamp figure. A UK review reported no effect on rats and squirrels after more than a week. Species and what a star line may prove stay on the Isotronic marten deterrent buying guide.

Which supply matches the car

Use 12 V on 78440 if you drive the car and a garage, or a competent fitter, lands terminal 15. Use cells if the job is no wiring, or the battery is a long lead away. Use 78580 if you want either supply in one box and you accept that the listing does not repeat the manual's sensor line. Take the supply off a car that will sit for weeks. None of those choices means the bay will clear.

Common questions

Will the 78440 flatten the battery?
The instruction quotes about 5 mA and tells you to disconnect the module if the car will sit. That is not a month of safe storage. No low-voltage cut-off is printed for this model.
What is terminal 15 for, in one sentence?
It is the ignition supply the 78440 uses, at the lock, the radio feed or the terminal-15 fuse, so the grey lead can run with the ignition off. It is not battery positive and it is not earth.
When are AA or AAA cells the better supply?
Cells are the better supply when you will not identify a 12 V lead, or when the battery is in the boot and a lead of about 100 cm will not reach it. The vibration LED and the six-AAA pair are the cell boxes here. UK reviews mention covers you may not get open, and the pair's eight-month line is a listing claim, not a drain test.
Does the 78580 UK listing include the vibration sensor?
No. The amazon.co.uk bullets for that listing do not state a vibration sensor, and they claim 40 m². A separate manual describes a vibration cut-out when the engine runs, about 60 m² indoors, and up to eight months on alkaline AA cells. Buy the box if you want four AA cells or a car lead in one unit.
What if the 12 V battery is in the boot?
A boot battery is a poor match for 78440. The lead is about 100 cm, which suits a bay, not a run to the back of a hybrid. Do not lengthen it and call that the fitting. Use a cell unit, or 78580 on AA cells, and leave the car battery alone. If you still want a hard-wired module, a garage has to see whether a proper feed exists.
Should a car that sits for weeks stay wired?
No. The 78440 instruction says to disconnect the module during a long lay-up, even at about 5 mA. A vibration cut-out on a cell box does not authorise leaving any of these units on a car that will not be started. Take the lead off, or take the box out, before the car is stored.

Related pages

Isotronic marten deterrent

Best Isotronic marten deterrent for a parked UK car

Isotronic marten deterrent buying guide for UK cars

How to fit an Isotronic marten deterrent in your car

Pine marten deterrent UK law before you fit one

Sources

Public UK sources used for this comparison. Shelf prices, stars and review counts are the amazon.co.uk figures captured for these five listings. Last checked 20 October 2026.

  1. Wildlife and Countryside Act 1981, Schedule 5 (retrieved 20 October 2026)
  2. NatureScot, pine martens (retrieved 20 October 2026)
  3. GOV.UK, hazel dormice (retrieved 20 October 2026)
  4. Bat Conservation Trust, rats and mice where bats are (retrieved 20 October 2026)
  5. ASA, pest repellents (retrieved 20 October 2026)
  6. Rentokil UK, mice repellent myths (retrieved 20 October 2026)
  7. Vincent Wildlife Trust, pine marten (retrieved 20 October 2026)
  8. Isotronic 78440 instruction (retrieved 20 October 2026)