Heated insoles for hunting, measured against the length of an actual sit
Every other page about these compares features. The only question that matters in a stand is whether the battery outlasts the daylight, and on published figures almost none of them do.
By Scooter M. · Published October 10, 2026
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Work out the length of your sit first, then read the runtimes. A late-season day in a stand is ten hours or more from the walk in to the walk out. Of the heated insoles whose makers publish a runtime at all, exactly one clears that - the Therm-ic C-Pack 1700 B at 17 hours on level one - and only on its lowest setting. Every other option here forces you onto the bottom setting too, which is the setting you notice least while sitting still.
The only specification that matters in a stand
Our heated insoles page ranks this category by how honestly each maker documents itself, and our heated socks for hunting page works through rationing a small pack across a long sit. This page asks the narrower question those two leave open: do any of these actually last a hunting day, and which one.
A hunting sit is not a ski run. You are not generating heat, you are not going inside at lunch, and you cannot plug anything in. The whole purchase comes down to one number held against one other number: published runtime, against hours on stand.
| Product | Energy per foot | Top setting | Bottom setting | Clears a 10 h sit? |
|---|---|---|---|---|
| Therm-ic Heat Flat + C-Pack 1700 B | Not derivable | 5.5 h (level 3) | 17 h (level 1) | Yes, on level 1 |
| Thermrup Electric Heated Insoles | 19.2 Wh | 2.7 h at its published 7 W | 6 h headline claim | No |
| Dr. Warm R4 | 8.1 Wh | 3 h (131°F) | 7 h (113°F) | No |
| SAVIOR app socks (for comparison) | 16.3 Wh | 2.5-3 h | 9-10 h | Close, with a spare pack |
Every figure is the maker's own published claim. We have measured nothing. Where a maker publishes both a voltage and a capacity we convert; where it does not, the row reads Not derivable and stays that way.
Read down the last column. One yes. That is the finding, and it is not a close call - the gap between 17 hours and the next-longest claim is almost three times over.
Quick picks
Tap any row to jump to the full write-up below. The energy column is the pack’s capacity times its voltage — the number this category does not print.
| # | Product | Best for | Energy | Price |
|---|---|---|---|---|
| 1 |  Therm-ic Heat Flat insoles + C-Pack 1700 B Bluetooth batteriesSeventeen hours on level one, published per setting — the only heated insole we found whose own numbers clear a dawn-t… | The only insole here that publishes a runtime longer than a full sit | — | $300.50View on Amazon |
| 2 |  Thermrup Electric Heated Insoles7.4 volts, 2,600 mAh per foot and a stated 7 W ceiling — three numbers almost nobody else in this category publishes, … | The only heated insole here with a published voltage AND a published wattage | 19.2 Wh | $69.95View on Amazon |
| 3 |  Dr. Warm R4 App-Controlled Heated InsolesThree settings published as 113°F, 122°F and 131°F with 7, 4 and 3 hours against them — the most complete insole spec … | A temperature AND a runtime for every setting | 8.1 Wh | $62.99View on Amazon |
| 4 |  SAVIOR HEAT Heated Socks with App ControlApp control sounds like a gimmick until you are laced into a ski boot and the only alternative is undoing everything t… | Adjusting heat without taking your boot off | 16.3 Wh | Check price on Amazon |
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Therm-ic Heat Flat insoles + C-Pack 1700 B Bluetooth batteries
Seventeen hours on level one, published per setting — the only heated insole we found whose own numbers clear a dawn-to-dusk sit with margin. It also will not tell you what is in the battery.
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The numbers
- Runtime
- 17 h / 9 h / 5.5 h — published per level
- Energy
- Not derivable — no capacity, no voltage published
- App levels
- 10, mapped to the 3 manual levels
- Charge time
- "7-9h", per Therm-ic
- Fit
- Trim-to-fit, marked for sizes 36 to 48
- Compatibility
- C-Pack batteries only
- Heat zones
- Ultra-fine element in the toe area, per Therm-ic
- Settings
- Three on the pack, ten in the app, with the mapping published: "Manual 1 = App Level 3, Manual 2 = App Level 6, Manual 3 = App Level 10"
- Care
- Not published for the insole; the packs are electronics and are not washable
On wattage: Not published, and not derivable either, because the capacity is missing. What Therm-ic does give is the cleanest runtime ladder in heated footwear: 17 h, 9 h and 5.5 h across three levels. The ratios are consistent with a roughly three-fold draw spread between bottom and top, which is the same shape as every other product on this site whose arithmetic we can actually check — so the figures look calculated rather than invented. We simply cannot put a watt number against them.
On the pack: Therm-ic publishes NO capacity and NO voltage for the C-Pack 1700 B, so the watt-hours are not derivable. The model name encodes 1700, which in this category conventionally denotes mAh, but Therm-ic does not state it as a specification and we are not going to convert a product name into an energy figure. This is the same disclosure gap we document on [Lenz](/heated-socks/lenz): the two premium boot-heating brands both publish excellent runtime matrices and neither publishes a voltage.
What we like
- Seventeen hours on level one is the only published insole runtime that clears a full day's sit with room to spare
- A runtime published for every one of its three levels, which most of this category does not manage
- Ten app levels with the manual-to-app mapping actually printed, so you know which setting you are on
- Trim-to-fit over a wide size range, with marked trim lines
- The packs mount outside the boot, so a spare can be swapped without taking the boot apart
What we do not
- No capacity and no voltage published, so the energy cannot be calculated or compared with anything else on this site
- By far the most expensive option here — several times the price of the next insole
- The app advertises a motion sensor and an eco mode, and Therm-ic does not publish what the motion sensor actually detects or does
- A 7-to-9-hour charge means a pack that runs out on day one is not ready for an early start on day two
- The insoles are sold separately from the packs as well, and the insole-only part cannot heat on its own
Who this suits
A hunter, ice angler or anyone else whose cold is measured in whole days rather than hours, and who would rather pay once than ration a small battery.
Who should skip it
You want to know what you are buying in energy terms, or your cold days are short. For a two-hour walk this is an enormous amount of money for warmth a cheaper insole would also deliver.
Spec sources: Therm-ic — C-Pack 1700 B battery for heated insoles ("Level 1: up to 17 hours", "Level 2: up to 9 hours", "Level 3: up to 5.5 hours"; 3 manual levels and 10 app levels with the mapping published as "Manual 1 = App Level 3, Manual 2 = App Level 6, Manual 3 = App Level 10"; Bluetooth with a "motion sensor and eco mode" whose function is not explained; charge time "7-9h"; compatible with the Insole Heat Kit, Insole Heat Flat and Insole Heat 3D only — NO capacity and NO voltage published anywhere) · Therm-ic — Insole Heat Flat (ultra-fine heating element in the toe area; cut-to-size with trim markings covering shoe sizes 36 to 48, and an instruction to follow the trim lines on the underside so the toe element is not cut through; neoprene and silicone construction; "compatible only with Therm-ic C-Pack Batteries"; no temperature or wattage published)
Thermrup Electric Heated Insoles
7.4 volts, 2,600 mAh per foot and a stated 7 W ceiling — three numbers almost nobody else in this category publishes, even if they do not quite agree with the six-hour claim.
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The numbers
- Energy
- 19.2 Wh
- Maker's stated energy
- 7.4 V, 2,600 mAh per foot — 19.2 Wh by our arithmetic
- Published ceiling
- max. 7 W — a rarity in this category
- Thickness
- 6 mm
- Sizes
- EU 35-48, trimmable
- Heat zones
- A single far-infrared rubber element running heel to toe, per Thermrup
- Settings
- Four, via an inline controller — no temperatures published
- Care
- Not published by Thermrup
On wattage: Thermrup publishes "max. 7W", which makes this one of the few heated products on this whole site with a stated wattage. It also complicates the runtime claim: 19.2 Wh at 7 W is 2.7 hours, not 6. The six-hour figure must describe a lower setting on the four-level controller, and Thermrup does not say which. Both numbers can be true; they cannot be true at the same time.
On the pack: Two 7.4 V, 2,600 mAh Li-Ion packs, one per foot, so the pair carries about 38.5 Wh. Thermrup also sells larger 7.4 V 3,000 mAh externals. The packs strap above the ankle and connect down a 70 cm cable, which is the standard arrangement and the standard annoyance.
What we like
- Publishes voltage, capacity AND maximum wattage — no other insole on this page does all three
- Far-infrared rubber element covers heel to toe rather than just the forefoot
- 6 mm is thin enough for most boots that were not bought a size up
- Larger 3,000 mAh externals are sold to extend the day
What we do not
- The 7 W ceiling and the 6-hour claim cannot describe the same setting — 19.2 Wh at 7 W is 2.7 hours
- No per-level runtimes and no temperature figures at all
- No washing instructions and no warranty published
- Battery packs sit above the ankle on a 70 cm cable, which is felt through a tight boot
Who this suits
Someone who wants heat under the whole foot and refuses to buy a battery whose voltage is a secret.
Who should skip it
You want to know what each of the four levels actually does. Thermrup publishes one runtime figure and no temperatures.
Dr. Warm R4 App-Controlled Heated Insoles
Three settings published as 113°F, 122°F and 131°F with 7, 4 and 3 hours against them — the most complete insole spec sheet we found, on a brand whose own two pages disagree about the battery.
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The numbers
- Energy
- 8.1 Wh
- Maker's stated energy
- 3.7 V, 2,200 mAh per foot — about 8.1 Wh
- Temperatures
- 113°F / 122°F / 131°F — published
- Runtimes
- 7 h / 4 h / 3 h — one for each setting
- Certification
- CE, RoHS, FCC, UKCA, UL, DOE per Dr. Warm
- Heat zones
- Full-length element, per Dr. Warm
- Settings
- Three, with temperatures published: 45°C, 50°C and 55°C (113°F, 122°F, 131°F)
- Care
- Do not submerge in water; clean the surface gently with a soft, damp cloth, per Dr. Warm
On wattage: Not published, but the arithmetic is clean: 8.1 Wh over the stated 3 hours on high is about 2.7 W, over 4 hours about 2.0 W, and over 7 hours about 1.2 W. A smooth descending ladder from a single pack size is what a calculated spec sheet looks like — which makes the capacity disagreement between Dr. Warm's own pages the more annoying, because these runtimes only work with the 2,200 mAh figure.
On the pack: 3.7 V and 2,200 mAh per foot on Dr. Warm's R4 specification page, which is about 8.1 Wh. A second Dr. Warm page for the same R4 says 1,500 mAh, which would be 5.6 Wh. We have used the larger figure because it is the one published alongside the per-setting runtimes, and it is the one those runtimes are consistent with.
What we like
- A temperature and a runtime for every setting, which is more than most heated JACKETS publish
- The runtimes invert into a smooth 2.7 / 2.0 / 1.2 W ladder, so they look calculated rather than invented
- A serious certification list, including UL
- App and remote control, with battery level reporting
What we do not
- Dr. Warm's own two pages for the R4 give different capacities — 2,200 mAh and 1,500 mAh
- One of those pages states "55℃/140℉", and 55°C is 131°F, not 140°F
- 8.1 Wh per foot is a small budget — three hours on high is the honest ceiling
- Not washable at all: surface wipe only
Who this suits
Someone who wants to set a temperature rather than a vague level, and to know what that choice costs in hours.
Who should skip it
You need certainty about what you are buying. A brand that publishes two different capacities for one model has not earned full confidence, however good the rest of the sheet is.
Spec sources: Dr. Warm — Heated Insoles with Remote Control R4, specification page ("3.7V", "2200mAh"; High "55°C / 131°F" 3 hours, Medium "50°C / 122°F" 4 hours, Low "45°C / 113°F" 7 hours; velvet top, EVA body; S-XL covering EU 35-46; "do not submerge the insoles in water"; CE, RoHS, FCC, UKCA, UL, DOE; "6-12 month warranty for most products") · Dr. Warm — Dr.warm Heated Insoles, second R4 page ("3.7V", "1500mAh", "Keep warm 3-8 hours", "Heat up to 55℃/140℉", 45°C/50°C/55°C settings, sizes S-XL 36-46, CE and RoHS) — differs from the R4 specification page on capacity, and its 55°C/140°F conversion does not hold
SAVIOR HEAT Heated Socks with App Control
App control sounds like a gimmick until you are laced into a ski boot and the only alternative is undoing everything to press a button you cannot reach.
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The numbers
- Energy
- 16.3 Wh
- Pack
- 7.4 V per sock
- Control
- Bluetooth app plus cuff button
- Fabric
- Carbon-fiber element in a knit sock
- Heat zones
- Toe box
- Settings
- Three, with temperatures published: 104-113°F, 122-131°F and 131-149°F
- Care
- Machine washable with the battery removed
On wattage: Not published, but derivable — which is the whole reason this sock leads the page. 16.3 Wh across the published 2.5-3 h on high is about 5.4-6.5 W, across 5-6 h on medium about 2.7-3.3 W, and across 9-10 h on low about 1.6-1.8 W. The hours in the table are the low end of each published range, so the implied draws are the upper bound. A smooth descending ladder from one pack size is what a calculated spec sheet looks like rather than an invented one.
On the pack: 7.4 V, 2,200 mAh per foot — about 16.3 Wh. SAVIOR publishes both numbers, which is more than Lenz does for a sock costing four times as much.
What we like
- Adjusting from your pocket is the single most useful feature on a heated sock
- Finer control than three fixed settings, which stretches the runtime
- Still works as a normal button sock if the phone dies
What we do not
- Bluetooth is one more thing to fail in the cold
- Phone batteries drain faster in the cold too
- No wattage published
Who this suits
Skiers, and anyone whose boots make the cuff button unreachable.
Who should skip it
You do not want an app on your phone for a pair of socks. That is a reasonable position.
Spec sources: Savior Heat — App-controlled heated socks product page ("7.4V 2200mAh battery"; High "2.5-3 hours" at "131-149°F", Medium "5-6 hours" at "122-131°F", Low "9-10 hours" at "104-113°F"; "One-Tap App Connection", "Live Battery Status Tracking", "Control Gloves, Socks & Apparel"; "the sock button for quick outdoor control"; "Heats up within 3 seconds"; COOLMAX fabric, carbon fiber elements; "Free 1-Year Extended Warranty"; the app itself is never named) · Amazon — SNOW DEER 7.4V 2200mAh replacement pack
The energy is smaller than a sock's, not bigger
Here is the thing most buyers have backwards, and it falls straight out of the numbers above.
- Dr. Warm R4 insole: about 8.1 Wh per foot (3.7 V, 2,200 mAh).
- SAVIOR heated sock: about 16.3 Wh per foot (7.4 V, 2,200 mAh).
Same capacity in milliamp-hours, half the energy - because the sock runs at twice the voltage, and watt-hours are volts times amp-hours. People buy insoles expecting the more serious product and frequently get the smaller battery. The honest exception here is Thermrup at 19.2 Wh per foot, which carries more than either.
So what is an insole actually better at? Bulk. It occupies space the boot had already given to an insole, where a sock adds a layer and a cuff pack. That is a genuine advantage and it is the whole argument of heated socks versus heated insoles - but it is an advantage about fit, not about endurance, and it matters most in a tight boot. Which brings us to the boot you are probably wearing.
A pac boot changes the form-factor argument
The space argument assumes a close-fitting boot. A tall rubber or pac boot - the standard for sitting in cold, wet country - is the opposite: deliberately roomy, often worn over a heavy sock already, with space for air to insulate.
In that boot the insole's main structural advantage largely evaporates. You have room for a heated sock and its cuff pack, which means you get to choose on the things that actually differ: energy per foot, where the element sits, and whether you can swap a dead battery without taking the boot off. On all three, a sock has a case. The pack clips at the cuff where a gloved hand can reach it, and spares are cheap.
The energy, converted
Watt-hours, and what they buy
Energy is capacity times nominal voltage. The ceiling draw is the pack’s own published output current times its voltage. The implied draw runs the maker’s advertised hours backwards. Nothing here is measured — check our working.
| Product | Capacity | Volts | Energy | Ceiling draw | Shortest runtime | Implied draw at the claim |
|---|---|---|---|---|---|---|
| Thermrup Electric Heated Insoles | 2,600 mAh | 7.4 V | 19.2 Wh | Not published | Not derivable | 3.2 Wat 6 h manufacturer's headline claim |
| Dr. Warm R4 App-Controlled Heated Insoles | 2,200 mAh | 3.7 V | 8.1 Wh | Not published | Not derivable | 2.7 Wat 3 h high, 55°c / 131°f |
| SAVIOR HEAT Heated Socks with App Control | 2,200 mAh | 7.4 V | 16.3 Wh | Not published | Not derivable | 6.5 Wat 2.5 h high (131-149°f) |
“Not derivable” means the manufacturer does not publish the figure the sum needs. We leave it blank rather than estimating it, borrowing a number from a similar model, or rounding one into existence. These are ceilings, not promises: cold, wind, movement and pack age all push real runtime below them. Run your own numbers.
Dr. Warm R4 App-Controlled Heated Insoles
- Energy in the pack
- (2,200 mAh ÷ 1000) × 3.7 V = 8.1 Wh
- Most the pack can deliver
- Not published — no output current stated, so the ceiling cannot be computed.
- And the draw the maker’s own claim assumes
- 8.1 Wh ÷ 7 h = 1.2 W — which is the low, 45°c / 113°f figure.
Two rows in that ledger read "Not derivable", and the reason is the most frustrating pattern in heated footwear. Therm-ic publishes no capacity and no voltage anywhere for the C-Pack 1700 B. The model name encodes 1700, which in this category conventionally means milliamp-hours, but a product name is not a specification and we are not going to convert one into an energy figure and present it as fact. That is exactly the position we take on Lenz, and it is no accident the two brands land in the same place: they are the two premium boot-heating names, they both publish the best runtime tables in the category, and neither will print a voltage.
The best-documented option here is also the cheapest
Thermrup costs a fraction of the Therm-ic set and publishes three numbers almost nobody else in heated footwear will: 7.4 volts, 2,600 mAh per foot, and a stated ceiling of "max. 7W". A published wattage is rare enough on this site to be worth noting wherever it appears.
And then those numbers argue with each other. 19.2 watt-hours drawn at 7 watts is 2.7 hours, not the six hours Thermrup headlines. Both figures can be true - the six-hour claim must describe a lower setting on the four-level controller - but Thermrup does not say which setting, so you cannot tell what you are getting at any given click of the dial.
For planning a sit, that is worse than a missing number. A gap you can work around by assuming the worst. Two figures that cannot both describe the same setting leave you unable to assume anything. It is the reason Thermrup sits second here rather than first despite being the most forthcoming maker on the page.
Two things that bite on a multi-day hunt
Charging. Therm-ic publishes a charge time of "7-9h". If a pack runs flat on day one and you are up at four for day two, it will not be ready, and no amount of planning changes the physics of that. Either carry a second set of packs or accept that the second morning runs short. Nobody mentions charge time when selling these and it is the thing that ruins the second day of a trip.
Cold-soaking the pack. You walk in warm, then sit for hours while everything on you drops toward ambient. Lithium cells deliver less at low temperature, which is the same effect we describe for phone batteries and app control - and the battery under your foot or strapped to your ankle gets no help from your body once you stop moving. Published runtimes are not cold-weather runtimes, and the published figure is the optimistic end.
Which one
You sit all day, in real cold, and want it solved
The Therm-ic Heat Flat set with the C-Pack 1700 B. Seventeen hours on level one is the only published insole runtime on this page that clears a full sit with margin, it gives a runtime for all three of its levels, the packs mount outside the boot so a spare swaps without unlacing, and the app prints the manual-to-app level mapping so you know where you are. It is also several times the price of anything else here, it will not tell you what is in the battery, and its own app advertises a motion sensor whose function Therm-ic never explains. Buy it because of the 17 hours, not because of the app.
You want the most honest spec sheet, and your sits are shorter
Thermrup. More energy per foot than anything else here at 19.2 watt-hours, a published voltage, a published capacity and a published wattage - and the only product on this page whose numbers you can actually audit. Accept that the six-hour claim and the 7-watt ceiling do not describe the same setting, run it below maximum, and treat it as a half-day product rather than a full-day one.
You want a temperature, not a vague level
The Dr. Warm R4, which publishes an actual temperature and an actual runtime against each of its three settings: 113°F for 7 hours, 122°F for 4, 131°F for 3. That is more disclosure than most heated jackets manage. The costs are real - 8.1 watt-hours is the smallest budget on this page, Dr. Warm's own two pages disagree about the capacity, and three hours on high is a ceiling rather than a pessimistic reading - but if you want to set a number instead of a guess, this is the one that lets you.
Honestly? Try a heated sock first
The SAVIOR app socks carry twice the energy of the Dr. Warm insole, put the element directly over the toes where numbness starts, cost less than half the Therm-ic set, wash in a machine, and clip their pack at the cuff where you can reach it in the dark with gloves on. In a roomy pac boot there is space for them. If your reason for looking at insoles was runtime rather than fit, the numbers point back at the sock - and heated socks for hunting works through rationing one across a long sit properly.
One more option that belongs in the conversation but not in the picks: an air-activated insole warmer, which has no battery, makes no noise, needs no charging and runs around nine hours a pair. It is a single-use chemical warmer rather than a heated insole, so it sits outside this page's category rather than inside its ranking - but heated socks versus toe warmers covers the chemical route properly, and for a single long sit it remains the cheapest honest answer in this whole category.
What we would skip, and why
- Therm-ic Heat Flat insoles bought without the C-Pack
- Therm-ic sells the insoles as a separate part, cheaper, and the listing sits in the same search results as the kit. The element is "compatible only with Therm-ic C-Pack Batteries" - there is no battery in that box and no other pack will run it. It is the same trap as the Lenz socks-only listing. Buy the set, or buy nothing.
- The 5,000 mAh no-name tier, however tempting the capacity looks
- There is a whole shelf of heated insoles advertising a 5,000 mAh pack - roughly double what Dr. Warm puts under your foot - for well under a hundred dollars. We looked. They publish a capacity in the listing title and no voltage anywhere, which means the watt-hours cannot be worked out and the headline runtime cannot be checked against anything. Several appear twice under different brand names at the same price, and none has a specification page to read. For a product you will rely on at first light, ten miles in, that is not a saving.
- Any insole on its top setting, for a sit
- This is the arithmetic below, stated as an instruction. The published top-setting runtimes here are 5.5 hours, 3 hours, and a figure Thermrup's own numbers put at 2.7. A sit is longer than all three. Plan the bottom or middle setting from the start, or plan to be cold at the end.
- Choosing an insole over a sock because of boot space, in a pac boot
- The space argument is real and we make it ourselves on heated socks versus heated insoles - an insole consumes room the boot had already allocated, which decides it in a close-fitting boot. A tall rubber or pac boot is not a close-fitting boot. In roomy hunting footwear that advantage largely disappears, and the reasons to pick a sock instead get their say.
- Trimming the insole by eye
- Therm-ic marks trim lines on the underside and tells you to follow them specifically so the toe element is not cut through. The element is in the toe. One careless cut with scissors turns a three-hundred-dollar set into an ordinary insole, and no warranty covers it.
Our criteria, and what we did not do
- Runtime measured against the thing being bought for - the length of a sit - rather than compared between products in the abstract.
- Every pack converted to watt-hours per foot where the maker publishes a voltage and a capacity, and marked "Not derivable" where it does not.
- Published wattage used where it exists, and checked against the runtime claim. Where the two disagree we say so rather than picking the flattering one.
- Availability verified before featuring, and re-verified since. The air-activated warmer and Therm-ic's insole-only part are both purchasable; they are left out for the reasons given rather than for stock, and the skip list says which.
- Insoles compared against a heated sock on the same axis, because for this use case the sock is the honest competitor and pretending otherwise would not serve a reader.
- We have not sat in a stand in any of these. Every figure is read off the makers' own published pages. How we work.
We have not worn, tested or owned any of these products, and we say so on every page rather than in a footer. What we do instead is compile the published specifications and do the arithmetic. The full method.
Frequently asked
- Do heated insoles last a full day of hunting?
- Almost none of them do. Measured against published figures, the only one we found that clears a ten-hour sit is the Therm-ic C-Pack 1700 B at up to 17 hours on level one - and that is its lowest setting. Dr. Warm publishes 7 hours on low and 3 on high; Thermrup headlines 6 hours while also publishing a 7-watt ceiling that its own 19.2 watt-hour pack would sustain for only 2.7 hours. Work out the length of your sit before you shop, not after.
- Are heated insoles or heated socks better for hunting?
- For a long sit in a roomy pac boot, usually socks. The insole's real advantage is bulk - it uses space the boot had already allocated - and that advantage matters most in a close-fitting boot, which a tall rubber hunting boot is not. On energy the sock often wins outright: a SAVIOR sock carries about 16.3 watt-hours per foot against about 8.1 for the Dr. Warm insole, because the sock runs at twice the voltage. The sock's pack also clips at the cuff where you can reach it mid-sit.
- Why can't you calculate the watt-hours for the Therm-ic insoles?
- Because Therm-ic publishes no capacity and no voltage for the C-Pack 1700 B. Watt-hours are volts times amp-hours, so without a voltage there is nothing to compute. The model name encodes 1700, which in this category usually means milliamp-hours, but a product name is not a specification and we will not convert one into an energy figure. Lenz does exactly the same thing - the two premium boot-heating brands both publish excellent runtime tables and neither prints a voltage.
- What heat setting should I use on a sit?
- The lowest one that keeps your toes comfortable, chosen before you sit down rather than after you get cold. The published top-setting runtimes on this page are 5.5 hours, 3 hours and an implied 2.7 hours - all shorter than a hunting day. Starting on high and working down is how people end up with a dead pack during the last hour of light, which on many sits is the hour that matters.
- Will the cold shorten the runtime below the published figure?
- Expect so. Lithium cells deliver less at low temperature, and a battery under your foot or strapped above your ankle gets very little help from your body once you stop moving. Published runtimes are measured in conditions kinder than a stand in late season, so treat them as the optimistic end of the range rather than a plan. It is also an argument for the product with the largest margin rather than the one that just barely clears your sit on paper.
- Can I buy the Therm-ic insoles on their own and use any battery?
- No. Therm-ic states the Heat Flat element is compatible only with its own C-Pack batteries, and the insole-only listing contains no battery at all. It sits in the same search results as the full kit at a much lower price, which makes it an easy and expensive mistake. Buy the set.
Sources
- Therm-ic - C-Pack 1700 B battery for heated insoles ("Level 1: up to 17 hours", "Level 2: up to 9 hours", "Level 3: up to 5.5 hours"; 3 manual levels, 10 app levels, mapping published as "Manual 1 = App Level 3, Manual 2 = App Level 6, Manual 3 = App Level 10"; Bluetooth with a "motion sensor and eco mode" whose function is not explained; charge time "7-9h"; compatible with the Insole Heat Kit, Heat Flat and Heat 3D only - no capacity and no voltage published)
- Therm-ic - Insole Heat Flat (ultra-fine heating element in the toe area; cut-to-size with trim markings for shoe sizes 36 to 48 and an instruction to follow the trim lines on the underside so the toe element is not cut through; neoprene and silicone; "compatible only with Therm-ic C-Pack Batteries")
- Thermrup - Electric Heated Insoles (7.4 V and 2,600 mAh per foot, which is about 19.2 Wh; "max. 7W" published ceiling; four-level inline controller; six-hour headline runtime claim with no setting attached; packs strap above the ankle on a 70 cm cable)
- Dr. Warm - Heated Insoles with Remote Control R4 ("3.7V", "2200mAh" - about 8.1 Wh; High "55°C / 131°F" 3 hours, Medium "50°C / 122°F" 4 hours, Low "45°C / 113°F" 7 hours; a second Dr. Warm page for the same model states 1500 mAh instead)
- Savior Heat - App-controlled heated socks ("7.4V 2200mAh battery" - about 16.3 Wh; Low "9-10 hours" at "104-113°F", Medium "5-6 hours", High "2.5-3 hours"; "the sock button for quick outdoor control")
Related
Heated Socks
One toe element, one 7.4V pack, roughly 16 watt-hours a foot. The simplest arithmetic on the site.
Heated insoles: the worst-documented corner of this whole category
The same "5000mAh, 4 levels, app control" specification appears under seven brand names and not one publishes a voltage. Three products survived the check.
Heated socks for hunting, where the sit is longer than the pack
Sixteen watt-hours a foot against a four-hour sit. How to ration it, and the boot-fit trap that ruins most attempts.
Heated socks or heated insoles?
One adds bulk around your foot, the other replaces something already in the boot. Boot room decides it.
Heated socks or disposable toe warmers?
Control is the real difference: one you can turn down, one runs until it is spent. Plus where the cost crosses over.
Heated vests for hunting, where sitting still changes the math
Stationary cold is the vest's best case. Which insulation, how to ration the pack, and why quiet fabric wins.
Watts, volts and the number on the label that is not quite true
Volts, amps, watt-hours and the labeling convention that overstates every tool-battery jacket by 11%.