How long will your battery run a dash cam in parking mode?
Battery capacity, the hardwire kit’s cutoff voltage, and what the camera actually draws while it sits there. The draw is the part no spec sheet gives you, so this page only carries draws measured with a meter at the camera, and it tells you when it is guessing.
Parking mode battery calculator
Hours from a rested battery to the hardwire kit’s cutoff, engine off, nothing else drawing
The short version
Hours to cutoff is the usable part of the battery divided by what the camera pulls from the 12 V side. Two of those three numbers are honest guesses unless someone measures them: how much of a car battery is really usable between rested and the kit’s cutoff, and how efficiently the hardwire kit turns 12 V into the camera’s 5 V. This page states both assumptions on the page, lets you change them, and gives the answer as a range rather than a number that looks more certain than it is.
A bracket, not a promiseHow the estimate is built
Four numbers go in and one comes out, and every one of them is labeled on the calculator with where it came from.
Battery capacity is the amp-hour rating off the label. A car battery is rated for a 20 hour discharge to a much lower voltage than any hardwire kit allows, which is why the next number exists.
Usable capacity is the fraction of that rating you actually get between a rested battery and the kit’s cutoff. The default is 60 percent, which is the working assumption my own parking rig uses for its 7 Ah sealed lead-acid battery between 12.7 V rested and an 11.9 V cutoff: 4.2 Ah of 7. It is an assumption, not a measurement. My rig has run cameras down to the cutoff, but it logs the battery’s voltage, not the current leaving it, so it times the discharge without counting the amp-hours that came out. The one overnight run checked below landed at the short end of the bracket, so read the long end as the optimistic one. A higher cutoff (the 12.2 or 12.4 V settings some kits offer) leaves less of the battery usable than that, not more. Lower the percentage if your kit cuts high, if the battery is old, or if it is cold.
The parking draw is the number nobody publishes and the reason this page exists. A measured preset is a mean read from a USB meter at the camera’s own input over a window of eight to ten minutes in parking mode, which sidesteps the second-to-second swing a spot reading carries. If you type a wattage instead, type what a meter at the camera shows, or what the maker’s table gives if it is in watts. If the maker gives amp-hours per 24 hours, use the third option: that is already a 12 V figure, so it needs no conversion.
The conversion from the camera’s 5 V draw to the battery’s 12 V side goes through the hardwire kit’s converter, and nobody publishes its efficiency either. On my bench the measured 5 V draws agreed with a maker’s own 12 V table at any efficiency between about 72 and 90 percent, which is the range a small buck converter lives in, so the calculator runs both ends and gives you the bracket. The kit’s own standing draw is invisible to a meter at the camera and is not in any figure here; it makes every result run a little long.
Then: usable amp-hours, divided by the 12 V current, is hours. A 50 Ah battery at 60 percent is 30 Ah; a camera pulling 3 W at its 5 V input needs 0.26 to 0.33 A from a 12.6 V battery through a 90 to 72 percent converter; 30 Ah over that is 90 to 113 hours. Change any input and the arithmetic follows.
Does the estimate match a real run to the cutoff?
A calculator built on two assumptions should be held against a battery that actually ran down. My rig has done that, and here is the calculator’s own arithmetic set beside the clock.
The COXPAL A17D in time lapse 1 fps, front and rear, on the rig's 7 Ah sealed lead-acid battery through the COXPAL 3-wire hardwire kit, from the ignition drop at 17:54 on 2026-09-20 to the kit’s cut at 03:27 the next morning. The calculator gets the same inputs: 7 Ah, the default 60 percent usable, and a 5 V draw.
| Draw put in | The calculator says | The battery ran |
|---|---|---|
| The night’s own: 4.04 W at 5 V (0.771 A), the meter’s accumulator over the whole park | 9.4 to 11.8 h | 9 h 33 min (9.55 h) |
| The preset: 3.81 W (0.725 A), the eight-minute desk mean the calculator offers for this mode | 10.0 to 12.5 h | 9 h 33 min (9.55 h) |
With the night’s own draw the run lands inside the bracket, 1.4 percent above its short end. With the preset it lands 4.5 percent short of the bracket’s short end (10.0 h), because over the whole night the camera drew 6.3 percent more than in the eight-minute desk window (0.771 A against 0.725 A at 5 V). A preset is a short mean, and a long park can run above it.
What one run cannot do is pull the two assumptions apart. Hours times watts gives their product: usable fraction times converter efficiency came to 0.44 that night. That is the default 60 percent usable through a 73 percent efficient converter, near the bottom of the 72 to 90 percent range, or less of the battery through a better converter. Either way, plan on the short end of the bracket. The battery also started short of a fair test: it was not rested and not provably full. It had been recharged that day after an earlier run to a cutoff, then powered the camera in normal recording for about 49 minutes before the park began (roughly 0.4 Ah at 12 V, an estimate), and no rested reading before the run exists. A rested, full battery would have run longer.
Data: the 12 V log bench-tools/logs/CKB-M1-bench-20260920_175235.csv and the evidence set evidence/CKB-parking-protocolB-a17d-2026-09-20 for the cut, evidence/CKB-parking-longpark-2026-09-20 for the 5 V meter (the meter's accumulator from just before the ignition drop to the cut, so it includes about 17 s of normal recording), all in the Dash Check repository.
The VIOFO A119M Pro in time lapse 1 fps, on the rig's 7 Ah sealed lead-acid battery through the VIOFO HK6 hardwire kit, from the ignition drop at 15:27 on 2026-09-23 to the kit’s cut at 08:35 the next morning. The calculator gets the same inputs: 7 Ah, the default 60 percent usable, and a 5 V draw.
| Draw put in | The calculator says | The battery ran |
|---|---|---|
| The night’s own: 2.54 W at 5 V (0.491 A), the meter’s accumulator over the whole park | 15.0 to 18.7 h | 17 h 8 min (17.14 h) |
| The preset: 2.53 W (0.489 A), the ten-minute desk mean the calculator offers for this mode | 15.1 to 18.8 h | 17 h 8 min (17.14 h) |
With the night’s own draw the run lands inside the bracket, 14.3 percent above its short end. With the preset it lands inside the bracket, 13.8 percent above its short end.
What one run cannot do is pull the two assumptions apart. Hours times watts gives their product: usable fraction times converter efficiency came to 0.49 that night. That is the default 60 percent usable through an 82 percent efficient converter, in the middle of the 72 to 90 percent range, or less of the battery through a better converter. The battery started fair: it rested at 12.86 V before the run, a full battery by the rig's own gate.
Data: the 12 V log bench-tools/logs/CKB-M1-bench-20260923_152520.csv and the evidence set evidence/CKB-parking-protocolB-a119mpro-2026-09-23 for the cut, evidence/CKB-parking-protocolB-a119mpro-2026-09-23 for the 5 V meter (the meter's accumulator from the first parking frame to the cut, the meter's own timer), all in the Dash Check repository.
Hardwire kit cutoff voltages
The hardwire kit is the thing standing between parking mode and a car that will not start. Every kit watches the battery voltage and cuts the camera below a threshold; some let you choose it. The first columns are the published figures for the kits on my bench, quoted from their manuals and packaging. The Measured on my rig column says what the kit actually did when the rig ran a camera down to its cut.
| Hardwire kit | Cutoff, 12 V system | Cutoff, 24 V system | Delay before it cuts | Output | Measured on my rig | Source |
|---|---|---|---|---|---|---|
| COXPAL 3-wire hardwire kit | 11.9 V | 23.9 V | not published | USB, 5 V | 11.93 V at the battery (stated 11.9 V), 2026-09-21, with the COXPAL A17D; did not switch back on | COXPAL A17S/A17D user manual, page 16: auto cut-off below 11.9 V on a 12 V system or 23.9 V on a 24 V system |
| VIOFO HK6 hardwire kit | 11.8 V / 12.0 V / 12.2 V / 12.4 V (slide switch) | 23.6 V / 24.0 V / 24.4 V / 24.8 V | cuts after the voltage stays below the set value for 90 plus or minus 10 seconds | USB-C, 5 V 3 A max | 11.72 V at the battery (stated 11.8 V), 2026-09-24, with the VIOFO A119M Pro; did not switch back on | VIOFO HK6 packaging and manual, read 2026-09-16: four cutoff points on a slide switch, 4 m cable, reverse-connection protection |
COXPAL 3-wire hardwire kit, measured. It cut the camera at 03:27 on 2026-09-21, 9 h 33 min into a park with the COXPAL A17D (its review has the whole night), with the battery posts reading 11.93 V. The posts sit a little above the voltage at the kit’s own lead while the camera draws through the fuse and wiring between them. The cut came 12.7 min after the posts first read 11.93 V: a delay in the kit, or the voltage taking that long to fall one more 10 mV step of the battery monitor, and one run cannot say which. The battery then rested back to 12.17 to 12.18 V over 2.6 h and the kit did not switch the camera back on. Evidence: evidence/CKB-parking-protocolB-a17d-2026-09-20.
VIOFO HK6 hardwire kit, measured. It cut the camera at 08:35 on 2026-09-24, 17 h 8 min into a park with the VIOFO A119M Pro (its review has the whole night), with the battery posts reading 11.72 V. The posts sit a little above the voltage at the kit’s own lead while the camera draws, but this kit’s own reading, which the camera stamps on every frame of its footage, ran about 60 mV above the posts all night (6,168 paired readings), so by its own measure it cut at 11.78 V against its 11.8 V setting. It cut 212 s after its own reading last showed 11.80 V, where VIOFO state 90 plus or minus 10 s, and 202 s when it cut again later with the ignition line on. Over the next 4 min 20 s the battery recovered to 11.90 V, above the setting, and the kit did not switch the camera back on; it did so when the ignition line was switched back on, which is what a kit should do. Evidence: evidence/CKB-parking-protocolB-a119mpro-2026-09-23.
A higher cutoff protects the start and shortens the park. A kit that cuts at 12.4 V is leaving the battery nearly full, so the usable fraction above should come down with it. A kit that holds for 90 seconds below the threshold, as the HK6 states, will ride through a short dip (a door lock, a dome light) rather than cutting on it. What the kits do at the moment of cutoff, whether they restore power as the battery recovers and how close to the stated figure they really trip, is what my rig’s runtime protocol is built to read. It has run cameras to the cut on both kits in the table. A kit’s reading joins the table the day the review of the camera it ran with publishes, the same gate the presets use, so the table never gets ahead of a review. COXPAL’s and VIOFO’s are in it now; the COXPAL A17D’s overnight battery curve and the VIOFO A119M Pro’s are the nights they came from.
Which dash cams have been measured?
Measured presets on this page: COXPAL A17D (4 parking configurations), VIOFO A119M Pro (6 parking configurations).
A preset on this page means a camera sat on my parking-mode rig, a 7 Ah sealed lead-acid battery feeding the camera’s own hardwire kit through a switch that stands in for the ignition, with a USB meter inline at the camera’s input. Each parking configuration is run in turn, the ignition switch is opened, and the meter’s accumulator is photographed at the start and the end of a window in parking mode: two and ten minutes after the drop for the COXPAL A17D, ten-minute windows for the VIOFO A119M Pro. The difference between the two photos is the mean, and that is the figure the preset carries, with the evidence folder it came from named beside it.
The rows are gated on the review, not on the measurement. A camera measured before its review publishes is committed to this page’s data file and stays dark until the review is live, the same day, automatically. Nothing here gets ahead of a review.
Normal recording draws for context, and the storage side of parking mode (a continuous parking mode can fill a card in a day), live in the storage calculator. If you are choosing the card that has to survive a long park, the SD card picker is the one to open.
What this cannot tell you
Whether the camera stays in parking mode that long. A camera can end a park on its own: a guard-time setting, a stationary timer, a thermal limit on a hot day. The calculator assumes the draw continues until the kit cuts, and a camera that ends the park early on its own is a finding for its review, not something this arithmetic can see.
Anything the car itself draws. Alarm, keyless entry, telematics, a trunk light that stays on. The calculator is the camera alone. A parked car’s own standing draw is often as large as the camera’s and comes off the same battery.
The battery’s real state. A five-year-old battery, a cold night, or a short drive that never fully recharged it all shrink the usable fraction below the default, and none of them shows on the label.
Alternator time. The estimate starts from a rested battery with the engine off. It does not model a camera that spends part of its life on a running car, and it does not add anything back for a start in the middle of the park.
What is not measured on this page yet. The usable fraction and the kit’s converter efficiency are still assumptions: the run to a cutoff checks what they come to together, not each one. The kit’s quiescent draw is not measured. The cutoff’s real trip point is measured for a kit once the review of the camera it ran with is out, and is the maker’s figure until then. The rig’s runtime protocol replaces these one at a time as it runs, and the page updates from the same data file.
Common questions about dash cam parking mode and batteries
How long will a car battery run a dash cam in parking mode?
Take the usable part of the battery and divide it by the camera's 12 V draw. With the assumptions this page states, a 50 Ah battery at 60 percent usable gives 30 Ah, and a camera drawing 3 W at its 5 V input pulls about 0.26 to 0.33 A from the 12 V side through the hardwire kit, so the kit's cutoff arrives after roughly 90 to 113 hours. A camera drawing twice that halves the time, a kit that cuts at a higher voltage shortens it further, and the car's own standing draw comes off the same battery.
What voltage should I set the hardwire kit cutoff to?
The kits on my bench publish cutoffs between 11.8 and 12.4 V on a 12 V system (23.6 to 24.8 V on 24 V). A higher setting leaves more charge for starting and gives a shorter park; a lower one does the opposite. If the car is driven daily and starts easily, the lowest setting the kit offers is the usual choice; if it sits for days, or the battery is old or the weather is cold, set it higher and accept fewer hours. A kit trips close to its published figure, not exactly on it: on my rig COXPAL's kit, rated 11.9 V, cut at 11.93 V read at the battery.
Does time-lapse parking mode use less power than continuous recording?
Not necessarily, and the only way to know is a meter at the camera. Some cameras keep the whole full-resolution pipeline running in time lapse and simply keep one frame in thirty, which can cost more power than a continuous low-resolution mode that turns the sensor path down. Time lapse always saves card space; whether it saves battery depends on the camera, which is why this page carries measured presets rather than a rule of thumb.
Why does the calculator give a range instead of one number?
Because a draw measured at the camera's 5 V input has to pass back through the hardwire kit's converter to become a 12 V current, and nobody publishes that converter's efficiency. On my bench the measured 5 V figures agreed with a maker's own 12 V table anywhere between about 72 and 90 percent efficiency, so the calculator runs both ends. A figure typed as amp-hours per 24 hours is already a 12 V number and gives a single answer.
Will parking mode drain my battery so the car will not start?
That is the hardwire kit's job to prevent: it cuts the camera when the battery falls to its threshold, which is set above the point where starting becomes doubtful. The risk comes from what the kit cannot see, an old battery whose usable capacity is far below its label, a cold night, or a car whose own standing draw continues after the camera is cut. A higher cutoff setting is the lever if starting matters more than hours.
Where these measurements come from
The parking rig is documented as CKB-BENCH-001: a 7 Ah sealed lead-acid battery through a fuse to the camera’s own hardwire kit, a switch on the ACC line, a Bluetooth battery monitor logging the rail, and a USB power meter inline at the camera. Its runtime protocol drains the battery to the kit’s cutoff per parking mode and reads the cutoff voltage off the log; its transition protocol drops the ignition live and watches what the camera does. The presets on this page are the meter’s accumulator means from those sessions, and every one names its evidence folder. The same rig’s draw tables feed the camera reviews, so a number here and a number in a review can never disagree.