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HOW-TO GUIDEHow to Store a Multimeter Safely (and Keep It Reading True)
A meter that has sat in a drawer for a year has a decent chance of letting you down: flat or leaking battery, stiff cracked leads, a blown fuse nobody remembers blowing. Storing one properly takes about sixty seconds. Turn the dial to off, unplug the leads and coil them loosely, keep the meter somewhere dry rather than in an unheated garage, and pull the battery out for anything longer than a couple of months.
Best Multimeter for Home Use
If yours has died in storage, this guide covers meters that are worth keeping around for household electrical jobs.
See Our Top Pick →What actually kills a stored multimeter
It is rarely the electronics. Digital meters are solid state and quite happy sitting idle. Three other things do the damage.
Battery leakage is the big one. An alkaline cell left in for years can vent potassium hydroxide, which creeps along the terminals onto the circuit board. By the time you notice the white crust, the damage is done.
Test lead degradation is the second. PVC insulation stiffens with age, and the copper strands break inside the sheath at the two points that get bent most: the strain relief where the lead meets the plug, and the same spot at the probe end. A lead can look perfect and still be open circuit.
Moisture is the third. An unheated UK garage swings between cold nights and warmer afternoons, and condensation forms on cold metal. That corrodes the rotary switch contacts and the input sockets, which shows up later as flickering readings or a range that only works if you wiggle the dial.
The sixty second shutdown routine
- Turn the dial to OFF. If your meter has no off position and relies on an auto sleep timer, park it on a high AC voltage range instead. Never leave it parked on current or resistance.
- Pull both leads out of the sockets. Leaving them plugged in with the dial on ohms lets the meter trickle current, and repeated bending at the plug is what eventually breaks the wire.
- Wipe the body, display and probes with a dry cloth. Flux residue, oil and finger grease all attract moisture.
- Run the leads through your fingers along their full length, feeling for nicks, flat spots and hard patches near the strain reliefs.
- Coil each lead in loose loops roughly the size of your hand. Wrapping them tightly round the meter body is the most common way leads get ruined.
- Put the meter and leads in the case with the probe tips capped or facing away from the display.
Where to keep it
Temperature and humidity
Most meters give a storage range around minus 10C to 50C, but temperature is rarely the problem in a British house. Humidity and cycling are. A cupboard indoors beats a garage every time. If the garage is your only option, use a sealed hard case with a couple of silica gel sachets and swap them out once a year.
The case matters
A blow moulded case or padded pouch stops the leads being crushed and keeps the meter from rattling against spanners. Tipping a meter loose into a toolbox scratches the display, dents the input sockets and knocks the rotary switch out of detent.
Quick Tip
Stick a strip of masking tape inside the case lid and write the fuse ratings and the date of the last battery change on it. Two years later, when the current ranges read nothing, you will know exactly which fuse to buy without stripping the meter down to read the old one.
Battery in or battery out?
Under three months, leave it in. Beyond that, take it out and drop it in the case beside the meter. That thirty second job removes the most likely cause of permanent damage.
This matters most with 9V PP3 batteries, which sit close to the board in a lot of compact meters. A weak cell is not just an inconvenience either: many meters lose accuracy before the low battery symbol appears, so readings taken on a tired battery can be quietly wrong.
Look after the leads more than the meter
The leads are the part that can actually hurt you. Cracked insulation on a lead you are pushing into a live consumer unit is a real shock risk, and a lead stored kinked or crushed no longer reliably meets the CAT rating printed on it.
Store them loose, never wrapped around the meter. If you are buying replacements, silicone leads stay flexible in the cold where PVC goes stiff and splits, which is worth the extra few pounds if your meter lives anywhere unheated.
Fuses and spares
Keep a spare pair of correctly rated fuses in the case. They must be the ceramic HRC type at the exact voltage and current rating the manual specifies. A glass fuse out of a car is not a substitute and can fail explosively on a fault. Storing spares with the meter turns a blown fuse into a five minute fix.
Long term storage checklist
- Battery removed and stored separately
- Leads inspected, wiped and loosely coiled
- Dial off, nothing plugged into the sockets
- Silica gel in the case if there is any damp risk
- Spare fuses and ratings noted inside the lid
- Calibration date recorded if you rely on the meter for work
Bringing it back into service
If the case has come in from somewhere cold, let it sit closed at room temperature for an hour before opening it. Opening a cold case in a warm room condenses moisture straight onto the meter.
Then fit a fresh battery and do a quick sanity check. Set the dial to ohms and touch the probe tips together: you should see close to zero, typically 0.2 to 0.5 ohms depending on the leads. A high or open reading means a broken lead, so flex each one near the plug while watching the display. Finish by measuring a known source, a new AA cell for example, to confirm the voltage function reads sensibly before you go near mains.
Can I store a multimeter in a cold garage?
You can, but condensation rather than cold is the risk. Use a sealed hard case with silica gel and let it warm to room temperature before opening. An indoor cupboard is better if you have one.
Should I take the battery out of my multimeter?
Yes, if it will sit unused for more than about three months. Alkaline leakage is the most common cause of a permanently dead meter, and removing the cell costs nothing.
Does storing a multimeter affect its accuracy?
Drift from sitting idle is very slow and most home users never notice it. Professionals recalibrate annually regardless. What does hurt accuracy is a weak battery and corroded switch contacts, both of which good storage prevents.