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Quick Picks
| Product | Best For | Price |
|---|---|---|
| CoolFire (The Original) - USB-C UV Free Solar Watch Fast Charger for All Eco Solar Watches. Safe 24/7 Charging (No 8H Timer Needed). Reloj Hombre Solar Charger. Fits G-Shock, Citizen, Seiko, Garmin WT | Leaving a watch charging without watching a timer | Check Price on Amazon |
| Solar Watch Fast Charger, Led Light for Charge Solar Watches with Size Caps, 8H Automatic Off Function Compatible Casio G Shock, Tough, Protrek, Seiko, Citizen, Garmin, Timex, Bering, FANMIS (White) | Hands-off overnight cycles with an auto shutoff | Check Price on Amazon |
| ECEEN Solar Watch Fast Charger, Led Light Charging Solar Watches with Men, Women & Square 3 Size Caps Compatible Casio G Shock, Tough, Protrek, Seiko, Citizen, Garmin, Timex, Bering, FANMIS | An 8-hour auto shutoff with a three-cap kit | Check Price on Amazon |
| NIXON Time Teller Solar A1369-100m Water Resistant Men's Analog Solar Watch | The longest published power reserve here | Check Price on Amazon |
| Timex Men's TW2U30300 Expedition Gallatin Solar Black Fabric Slip-Thru Strap Watch | A light-powered field watch with a stated two-month power reserve | Check Price on Amazon |
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Last Updated: September 2026
Short days and flat grey overcast expose the one real weakness of a light-powered watch: the dial only banks energy when light actually lands on it. Under a coat sleeve, in an office, in a climate where the sun is a rumour from November to March, a solar watch can drift toward its low-power warning even though nothing is wrong with the movement.
This page is a specification-led roundup of the gear that addresses that: four light-powered watches whose listings publish how they store energy, and six LED charging units built to top a dial up indoors. Nobody on this site wore, wired up or timed any of these products. Every number below comes from the Amazon Creators API verified product record and the product listing feature bullets retrieved on 2026-09-09, and it is attributed to whoever published it.
What you will find: a quick picks table, a plain-language section on what to look for in an indoor charger, ten product sections with their real published specs, and an honest note about where the supplied evidence runs out.
- SAFE 24/7 CHARGING (NO TIMER NEEDED) – TRUSTED BY 300,000+ CUSTOMERS. Rated 4.5 out of 5 stars, the CoolFire is the industry standard. We use calibrated 40,000 LUX UV-free LEDs
- ZERO FAILURE POINTS (NO SWITCHES TO BREAK) – CHARGE FASTER & SAFER. Compatible with Seiko, Garmin, Citizen, Timex, G Shock, Rangeman, Protrek, and more. While other chargers use
- 【Premium Solar Powered Watch Charger】This solar watch charger adopts 22 LED lights to simulate natural solar spectrum, it delivers sunlight-grade illumination without overheating
- 【8H Timing Off Lamp Watch Charger】The solar watch fast charger featuring 8-hour auto shutoff that matches standard charging cycles of most solar watches, it enables hands-free
- 【Premium Solar Powered Watch Charger】This solar watch charger adopts 22 LED lights to simulate natural solar spectrum, it delivers sunlight-grade illumination without overheating
- 【8H Timing Off Lamp Watch Charger】The solar watch fast charger featuring 8-hour auto shutoff that matches standard charging cycles of most solar watches, it enables hands-free
- Powerful Japanese Solar Quartz Movement: The Time Teller Solar features a Miyota-2170 Japanese solar powered quartz movement, ensuring accurate timekeeping while eliminating the
- Enduring Design for Any Era: With its classic silhouette and solid stainless steel construction, this watch is built to last for generations. It combines timeless style with
- Adjustable black 22mm fabric double-layer strap fits up to 8-inch wrist circumference
- Charged by any light with a two-month power reserve
- SAFE 24/7 CHARGING (NO TIMER NEEDED) – TRUSTED BY 300,000+ CUSTOMERS. Rated 4.5 out of 5 stars, the CoolFire is the industry standard. We use calibrated 40,000 LUX UV-free LEDs
- ZERO FAILURE POINTS (NO SWITCHES TO BREAK) – CHARGE FASTER & SAFER. Compatible with Seiko, Garmin, Citizen, Timex, G Shock, Rangeman, Protrek, and more. While other chargers use
- SAFE 24/7 CHARGING (NO TIMER NEEDED) – TRUSTED BY 300,000+ CUSTOMERS. Rated 4.5 out of 5 stars, the CoolFire is the industry standard. We use calibrated 40,000 LUX UV-free LEDs
- ZERO FAILURE POINTS (NO SWITCHES TO BREAK) – CHARGE FASTER & SAFER. Compatible with Seiko, Garmin, Citizen, Timex, G Shock, Rangeman, Protrek, and more. While other chargers use
- SAFE 24/7 CHARGING (NO TIMER NEEDED) – TRUSTED BY 300,000+ CUSTOMERS. Rated 4.5 out of 5 stars, the CoolFire is the industry standard. We use calibrated 40,000 LUX UV-free LEDs
- ZERO FAILURE POINTS (NO SWITCHES TO BREAK) – CHARGE FASTER & SAFER. Compatible with Seiko, Garmin, Citizen, Timex, G Shock, Rangeman, Protrek, and more. While other chargers use
Why Solar Watches Struggle in Winter
A light-powered watch converts whatever hits the dial into stored charge. Three things stack against that in winter: fewer daylight hours, heavy cloud cover, and long sleeves. None of those break the watch, but together they can tip the balance so the cell discharges faster than the dial refills it.
That is the whole logic behind an indoor LED charger. Instead of hoping for a bright window ledge in February, you put the dial under a controlled light source for a defined stretch. If your watch is already showing a low-power indication, or if it lives under a cuff all day, that is the fix worth buying.
One caveat: the listings themselves market these units around avoiding heat and UV exposure, but the supplied bullets do not establish that light exposure itself carries no risk — the 8H listings market their shutoff specifically to avoid prolonged charging. Follow your own watch manufacturer's charging guidance rather than a third-party charger's marketing copy, and check the CPSC for recall notices before buying any powered accessory. Recall notices and general consumer product safety information are published by the CPSC. USA.gov's consumer protection pages cover complaint and warranty basics.
What to Look For in Winter Solar Charging Gear
- A published power reserve. A watch that states how long it runs off a full charge tells you how much winter it can absorb before you intervene. Two of the four watches here publish a figure; two do not.
- A stated UV position. Direct sun ages straps and dials. The chargers here are sold specifically on being UV-free or near-zero UV, which is the point of using them instead of a window sill.
- Cap fit for your case shape. A silicone or rubber cap holds the watch at the right distance from the LEDs. Round-only caps are a problem for square G-Shock-style cases.
- Timer behaviour. An 8-hour auto shutoff is convenient overnight; a no-timer design is convenient if you want to leave the watch sitting there. Decide which failure mode annoys you less.
- Cable and power input. USB-A versus USB-C matters if you plan to run the charger from a laptop or a power bank.
- A battery backup on the watch itself. Some listings describe a hybrid solar-plus-battery arrangement, which changes what a dark winter actually costs you.
The Indoor Chargers
Solar Watch Fast Charger, Led Light for Charge Solar Watches with Size Caps, 8H Automatic Off Function Compatible Casio G Shock, Tough, Protrek, Seiko, Citizen, Garmin, Timex, Bering, FANMIS (White) — Best for hands-off overnight charging cycles
This is the timer-first approach. This listing states the charger uses 22 LEDs to simulate the natural solar spectrum, is USB-powered for indoor and nighttime charging, and has overcharge protection and nearly zero UV radiation. Read that carefully: "nearly zero UV" is the seller's phrasing, not an independent measurement, and it is a weaker statement than "UV-free."
The charging behaviour is the interesting part. It offers two brightness levels the listing rates up to 20000+ and 40000+ Lux, plus an 8-hour auto shutoff the seller says matches the standard charging cycle of most solar watches. The practical inference: put the watch on before bed, and the unit stops on its own before you wake up. If you want a longer session, you will be restarting it manually.
The box, per the listing, contains the charger, a user manual, three silicone protective caps and a 1.5m charging cable, and the unit works with 5V power adapters. The listing names Garmin, Citizen, Timex, Bering, Seiko, G Shock, Tough, Rangeman, Protrek, Illuminator, FANMIS, Pulsar, Fossil, MASTOP, Gosasa and HOLZKERN among compatible brands — a seller compatibility claim, so verify against your specific model.
Pros
- Two brightness settings rated up to 20000+ and 40000+ Lux, so you can run a slow daily top-up or a faster recovery
- 8-hour auto shutoff removes the risk of forgetting the unit is on
- Three silicone caps cover round, square, men's and women's case sizes
- 1.5m cable gives some placement freedom on a nightstand
- The 8-hour cutoff means a longer unattended session is not possible without re-triggering it
- The listing claims "nearly zero UV radiation," which is a seller statement rather than a certified figure
- The listing also warns against direct eye exposure to the LED light, so this is not a bedside lamp substitute
ECEEN Solar Watch Fast Charger, Led Light Charging Solar Watches with Men, Women & Square 3 Size Caps Compatible Casio G Shock, Tough, Protrek, Seiko, Citizen, Garmin, Timex, Bering, FANMIS — Best for auto-shutoff charging with a three-cap kit
Here is the thing about this one: ECEEN's listing publishes the same core specification: 22 LEDs, an 8-hour timing off function, three silicone caps sized for men's, women's and square watches, dual brightness up to 20000+ and 40000+ Lux, and a 1.5m cable. The two records are functionally twins on paper, with the branding and the gift-angle bullet being the visible difference in the supplied data.
Like the white 8H unit above, its cap set is described as sized for square as well as round cases. If you own a square-cased digital — the Casio-style rectangles the listing references — a cap sized for that shape holds the dial flat and square to the LED array instead of tilting it. That is a fit detail, not a performance claim, but fit is what determines whether the dial actually sees the light.
Its bullets also state the charger is exclusively compatible with eco solar watches and works with all 5V power adapters. Take the word "exclusively" seriously: this is a charger for light-powered watches, not a dock for a smartwatch with electrical contacts.
Pros
- Three caps explicitly sized for men's, women's and square watches
- Same dual brightness levels, rated up to 20000+ and 40000+ Lux
- 8-hour timing off function for unattended overnight use
- Runs from any 5V adapter, per the listing
- Branded differently from the near-identical white unit above, but the supplied bullets do not establish a performance difference between them
- Restricted by the seller to eco solar watches only
CoolFire (The Original) - USB-C UV Free Solar Watch Fast Charger for All Eco Solar Watches. Safe 24/7 Charging (No 8H Timer Needed). Reloj Hombre Solar Charger. Fits G-Shock, Citizen, Seiko, Garmin WT — Best for continuous, no-timer charging
This is the opposite design philosophy, and it is stated openly in the copy. CoolFire's listing describes calibrated 40,000 LUX UV-free LEDs and says the watch can be left plugged in indefinitely with no timer required. Note the difference in claim strength versus the units above: "UV-free" rather than "nearly zero UV." The supplied CoolFire bullets do not state how many brightness levels the charger offers.
The hardware argument follows from that. The listing describes a Solid-State Direct Drive design with no switches or timer chips, and includes a USB Type-C cable plus two soft rubber caps that set the watch at the intended focal distance from the LEDs. Fewer moving parts is a reasonable durability inference, though the supplied record contains no failure-rate data for any charger here, so treat it as the seller's engineering rationale rather than a proven outcome.
On social proof: the bullets claim the product is trusted by 300,000+ customers and rated 4.5 out of 5 stars, and back it with a 12-month warranty and a 30-day money-back guarantee. That rating figure appears inside the seller's own marketing bullet, so read it as a merchant statement, not as an independently verified aggregate.
Pros
- Stated UV-free LEDs calibrated at 40,000 LUX
- No timer to re-trigger; the listing states the watch can stay on it indefinitely
- USB Type-C cable connects to a laptop, power bank or wall adapter
- 12-month warranty and a 30-day money-back guarantee
- Two caps rather than the three supplied with the ECEEN and white 8H units, so square-case owners should confirm fit
- No adjustable brightness levels are stated in the supplied bullets
- The 4.5-star and 300,000-customer figures come from the seller's own listing copy
CoolFire (The Original) - USB-C UV Free Solar Watch Fast Charger for All Eco Solar Watches. Safe 24/7 Charging (No 8H Timer Needed). Reloj Hombre Portable Charger. BK — Best for buyers choosing the BK listing suffix
Same charger, different listing. The BK listing publishes the same 40,000 LUX UV-free LED specification, the same Solid-State Direct Drive description, the same USB Type-C cable and two rubber caps, and the same 12-month warranty and 30-day money-back guarantee.
So the honest guidance is simple: choose between the CoolFire listings on listing suffix and current availability, because the supplied feature bullets do not distinguish them on output, cap count, cable type or warranty. Anyone telling you one variant charges faster is not reading the same record.
Pros
- Identical published charging specification to the other CoolFire listings
- USB-C input for laptop or power bank use
- No timer chip or switch in the stated design
- Ships with two caps, so unusual case shapes may not seat as well as with a three-cap kit
- Nothing in the supplied bullets differentiates it functionally from the other CoolFire variants
CoolFire (The Original) - USB-C UV Free Solar Watch Fast Charger for All Eco Solar Watches. Safe 24/7 Charging (No 8H Timer Needed). Reloj Hombre Solar Charger. Fits G-Shock, Citizen, Seiko, Garmin SV — Best for buyers choosing the SV listing suffix
The SV listing publishes the same 40,000 LUX UV-free LED specification, the same Solid-State Direct Drive description, the same USB Type-C cable and two rubber caps, and the same 12-month warranty and 30-day money-back guarantee.
What that means for a buyer in a cloudy climate: the decision that actually matters is timer versus no-timer, and cap count. Once you have made that call, the supplied bullets do not distinguish the CoolFire listings, which differ only by listing suffix.
Pros
- Stated UV-free output at a calibrated 40,000 LUX
- Continuous-use design with no auto shutoff to manage
- Backed by the same 12-month warranty terms as the other CoolFire listings
- Two caps only
- No adjustable brightness levels are stated in the supplied bullets
CoolFire (The Original) - USB-C UV Free Solar Watch Fast Charger for All Eco Solar Watches. Safe 24/7 Charging (No 8H Timer Needed). Reloj Hombre Solar Charger. Fits G-Shock, Citizen, Seiko, Garmin GY — Best for buyers choosing the GY listing suffix
And the fourth listing. The GY listing publishes the same 40,000 LUX UV-free LED specification, the same Solid-State Direct Drive description, the same USB Type-C cable and two rubber caps, and the same 12-month warranty and 30-day money-back guarantee.
Look, four listings for one design is a merchandising decision, not a product range. Compare the current offers and take whichever listing is in stock.
Pros
- Identical published specification to the WT, BK and SV listings
- No-timer operation suits people who charge in irregular bursts
- USB-C cable included
- Nothing in the supplied record separates it from its sibling listings
The Watches
NIXON Time Teller Solar A1369-100m Water Resistant Men's Analog Solar Watch — Best for the longest published power reserve here
If your problem is a watch that stops during a dark stretch, the reserve figure is the spec to read first. Nixon states the Time Teller Solar's dial captures sunlight or ambient light for up to 4 months on a single charge. On paper that is twice the buffer of the Gallatin Solar's published figure, which is a meaningful margin if you go weeks without meaningful daylight on your wrist.
The build is specified in detail. Nixon's listing specifies a Miyota-2170 Japanese solar powered quartz movement, a 40.5mm case, a 10 ATM / 100m water rating, hardened mineral crystal, a stainless steel crown and a screw-down caseback. A screw-down caseback and a 100m rating point at a watch meant to be worn through weather rather than babied indoors.
Strap logistics matter more in winter than people admit, because you are sizing over sleeves and gloves. The 20mm 5-link Quick-Release bracelet uses a Quick Adjuster buckle for tool-free sizing, per the listing.
Pros
- Manufacturer-stated reserve of up to 4 months on a single charge
- 10 ATM / 100m water rating with a screw-down caseback
- Hardened mineral crystal and stainless steel construction
- Tool-free bracelet adjustment via the Quick Adjuster buckle
- A steel bracelet and 40.5mm case is a dressier proposition than the resin-cased options here
- The supplied listing does not state a recharge time from empty
Timex Men's TW2U30300 Expedition Gallatin Solar Black Fabric Slip-Thru Strap Watch — Best for a light-powered field watch with a stated two-month power reserve
Timex's listing for the Expedition Gallatin Solar says it is charged by any light and holds a two-month power reserve. "Any light" is the phrase that matters for indoor winter charging — it is the manufacturer's own framing of ambient-light recovery, and it pairs logically with an LED charger on the days the sky never really opens.
The Gallatin Solar listing specifies a black 45mm resin case with an acrylic lens, luminous hands, a black dial with a date window at 3 o'clock, and an adjustable 22mm double-layer fabric strap that fits up to an 8-inch wrist. Timex states that slip-thru fabric strap is an adjustable 22mm double-layer strap that fits up to an 8-inch wrist circumference.
Timex rates it water resistant to 50 m (165 ft), which its listing describes as generally suitable for short periods of recreational swimming but not diving or snorkeling. An acrylic lens is more scratch-prone than mineral glass as a material class.
Pros
- Charged by any light, per Timex, with a stated two-month reserve
- Adjustable 22mm double-layer fabric slip-thru strap fits up to an 8-inch wrist circumference, per Timex
- Luminous hands and a date window at 3 o'clock
- Timex states a black 45mm resin case with an acrylic lens and luminous hands; no weight figure is given in the supplied listing information
- Acrylic lens rather than mineral or sapphire
- Two-month reserve is half the figure Nixon publishes for the Time Teller Solar
- Not rated for diving or snorkeling
FANMIS Men's Solar Powered Casual Quartz Wrist Watch Analog Digital Multifunctional Black Sports Watch (Black) — Best for a hybrid solar-and-battery backstop
This one addresses the winter anxiety differently. The FANMIS listing says the solar panel supplies sunlight or light power to the watch, and that without sun or light the power supply comes from the battery. That is a hybrid arrangement, and it is genuinely relevant to a cloudy climate: light tops it up when available, and the battery carries it when light is not.
The rest is sports-watch construction. The same listing cites a 1 year manufacturer warranty, high hardness resin glass, a shockproof PC polycarbonate front case, Japanese movements, and 50 m / 164 ft water resistance, with a note not to press any buttons in the water. A shockproof PC polycarbonate front case suggests impact tolerance.
FANMIS is one of the brands named in the charger compatibility lists above, as are Timex and Citizen; those are brand-level seller claims and do not establish cap fit for any specific case.
Pros
- Battery supplies power when there is no sun or light, per the listing
- Shockproof PC polycarbonate front case and high hardness resin glass
- 50 m / 164 ft water resistance
- 1 year manufacturer warranty stated on the listing
- No power reserve duration is stated in the supplied listing information
- Buttons must not be pressed underwater
- The listing's own bullets conflict on the crystal, describing both "high hardness resin glass" and a "mineral glass mirror," so confirm the material with the manufacturer
VIGOROSO Solar Watches for Men Stainless Steel Analog Digital Wrist Watches — Best for a large steel analog-digital dial
VIGOROSO's listing describes a double solar and lithium battery powered quartz movement. Same idea as the FANMIS in principle — two power sources rather than one — but wrapped in steel instead of resin.
The listing describes a very big face at 48mm, a blue dial with silver hands, a stainless steel band, and an analog and digital display. Its listing also cites high hardness glass, a key scratch resistant watch face, and a stainless steel water proof case cover, and describes the watch as heavy. That combination — 48mm and heavy — is the honest tradeoff: a large dial is easy to read, but it will dominate a smaller wrist. The supplied listing information for B08CGLR1S4 does not state a solar cell size or charging rate, so case diameter alone says nothing about how much light it captures.
A note on scope: the listing calls the case cover water proof but the supplied bullets do not state a depth or ATM rating, unlike the Timex, Nixon and FANMIS records. Treat it as splash-oriented until the manufacturer confirms a rating.
Pros
- Double solar and lithium battery powered quartz movement
- Stainless steel band, clasp and case cover
- High hardness, key scratch resistant watch face
- 48mm analog and digital dial is easy to read at a glance
- No water resistance depth or ATM rating appears in the supplied listing information
- Described by the listing as very big and heavy, which will not suit every wrist
- No power reserve duration is stated in the supplied listing information
How We Research
The method here is documentary, not physical. For each product we pulled the Amazon Creators API verified product record and read every product listing feature bullet, all retrieved on 2026-09-09, then compared them attribute by attribute: stated power reserve, LED output in Lux, cap count and shape, cable type, timer behaviour, water resistance rating and warranty terms.
Where two listings publish the same value, we say so instead of manufacturing a difference. Where a listing is silent — a recharge time, a water rating, a review count — we say the supplied listing information does not state it, which is not the same as saying the manufacturer never publishes it elsewhere. Marketing adjectives like "sunlight-grade" and "industry standard" are reported as seller language, not as findings.
Recommendations by Use Case
If you want the longest published buffer against dark weeks: the NIXON Time Teller Solar A1369-100m Water Resistant Men's Analog Solar Watch, because Nixon states up to 4 months on a single charge and pairs it with a 10 ATM / 100m rating and a screw-down caseback.
If you would rather not restart a timer: any of the CoolFire listings, whose bullets state 40,000 LUX UV-free LEDs and a no-timer design; how long to leave a watch charging is a question for your watch manufacturer.
If you would rather the charger switched itself off: the white 8H unit or the ECEEN, both of which publish an 8-hour auto shutoff, 22 LEDs, two brightness levels up to 20000+ and 40000+ Lux, and three silicone caps.
If you want a three-cap kit: the white 8H unit or the ECEEN; both listings describe caps covering round, square, men's and women's watch sizes.
If you want a battery behind the solar cell: the FANMIS, whose listing states the power supply comes from the battery without sun or light, or the VIGOROSO with its double solar and lithium battery movement.
Frequently Asked Questions
Do these chargers emit UV? The CoolFire listings describe the LEDs as UV-free; the 8H units describe nearly zero UV radiation. Those are two different claim strengths from two different sellers, and neither is an independent certification in the supplied records.
How long should I leave a watch on the charger? The 8-hour auto shutoff on the white and ECEEN units is described by the seller as matching the standard charging cycle of most solar watches. Your own watch brand's guidance overrides any third-party charger's suggestion.
Why is my solar watch not holding charge in winter? Usually because the dial is not receiving enough light — sleeves, short days and cloud all reduce it. A watch with a stated reserve, like the two-month figure Timex publishes or Nixon's up-to-4-month figure, tells you roughly how much darkness it is designed to absorb before you need to intervene.
Will one of these chargers work with an Eco-Drive? The listings name Citizen among compatible brands, and the CoolFire bullets specifically list Citizen Eco-Drive. Compatibility statements on a listing are seller claims, so confirm against your exact model before buying.
Is the 8-hour timer or the no-timer design better? Neither is objectively better. The timer removes the risk of forgetting the unit is running; the no-timer design removes the need to restart it. Decide which you would actually forget to do.
Can I use a bright desk lamp instead? The supplied records give no comparative data for household lamps, so there is nothing here to support that substitution. What they do establish is the Lux figures the chargers publish, which is the number to compare against if you go looking.
Final Verdict
If you are buying one thing to solve winter, buy a charger, not a new watch — a light-powered movement you already own will happily take a top-up. Between the two design camps, the CoolFire units make the cleaner promise for people who charge irregularly, because the listing explicitly permits leaving the watch plugged in with no timer to manage. The 8H units answer a different question well: three caps instead of two, plus a shutoff that saves you from yourself.
If you are buying a watch outright for a cloudy climate, the Nixon's manufacturer-stated up-to-4-month reserve is the single most useful number on this page, and the 10 ATM / 100m rating means it is not a fair-weather piece. The Timex Men's TW2U30300 Expedition Gallatin Solar has half that stated reserve and an adjustable fabric strap that fits up to an 8-inch wrist circumference. The FANMIS and VIGOROSO take the hybrid route, keeping a battery behind the cell — a reasonable hedge if your winter genuinely has no sun at all.
Sources & Methodology
This website does not run a lab and did not physically or laboratory-test any watch or charger on this page; nothing here was worn, plugged in, timed or measured by anyone on our side. What we did do is read the Amazon Creators API verified product record and every product listing feature bullet for all ten ASINs on 2026-09-09, then line them up against each other on the attributes that actually decide a winter purchase — stated power reserve, LED Lux output, cap count and shape, timer behaviour, cable type and water rating — and flag where a listing simply does not say. For a category like this, that documentary comparison is enough to tell you which charger fits your case shape, which one stops by itself, and which watch publishes the longest buffer against a dark month; it cannot tell you how quickly any of them refills a specific cell, because none of the supplied records state a recharge time.