6 River 2 Solar Power Bank of 2026 for Off-Grid Power

The EcoFlow RIVER 2 Pro is a high-capacity portable power station engineered to supply dependable off-grid electricity for road trips, outdoor adventures, mobile workstations, and home emergency backup. Equipped with a 768Wh battery capacity and an 800W continuous AC output, this model bridges the gap between handheld phone chargers and large, stationary home backup generators. It is designed for outdoor enthusiasts, remote professionals, and families who need to power multiple personal electronics, laptops, and modest home appliances away from conventional electrical outlets.

In terms of real-world output, the RIVER 2 Pro features 11 versatile outlets spanning standard AC receptacles to USB-C ports, with the ability to handle appliances drawing up to 1600W through internal output-boosting technology. The 768Wh energy capacity enables users to power essential gear simultaneously without overloading the unit. Internal energy storage relies on durable LFP (Lithium Iron Phosphate) battery cells rated for more than 3,000 charge cycles before dropping to 80 percent capacity, providing nearly ten years of regular service. An integrated Battery Management System (BMS) continuously regulates voltage, current, and operating temperature to preserve internal cell health.

The physical structure prioritizes portability and straightforward operation, measuring 10.5 by 10.1 by 8.5 inches and weighing approximately 17.2 to 18.2 pounds. A sturdy rear-facing handle provides a secure grip when lifting the station in and out of a vehicle trunk or moving it around a job site. The front panel neatly organizes the AC outlets, USB-C and USB-A connections, DC ports, and an informative display screen that provides clear readings for real-time power consumption, input wattage, and remaining runtime.

Recharging the internal power pack is exceptionally fast, taking only 70 minutes to reach a complete charge from a standard AC wall outlet via EcoFlow's X-Stream fast-charging system. For off-grid replenishment, the unit accepts up to 220W of solar input, allowing users to achieve a full battery recharge in approximately 3.5 hours under optimal outdoor conditions. The package includes an AC wall charging cable and user manual, ensuring immediate operational readiness right out of the box without requiring specialized third-party adapters.

The main limitation of the RIVER 2 Pro comes down to physical scale when compared against everyday-carry battery packs. Weighing over 17 pounds, this unit is intended for vehicle transport, basecamp utility, or household emergency kits, and it is not suitable for airline travel or daily commuter backpacks. Additionally, while its 800W continuous output easily supports consumer electronics, televisions, and small kitchen equipment, it cannot run heavy continuous loads like whole-room electric space heaters, standard electric clothes dryers, or large electric ovens.

The EcoFlow RIVER 2 Pro is an outstanding choice for campers, mobile content creators, and homeowners who want rapid wall recharging, versatile 11-port connectivity, and the extended lifespan of LFP battery chemistry. Commuters looking exclusively for pocketable phone power should opt for a lightweight handheld power bank. However, for users who need a dependable, fast-recharging power hub capable of supporting laptops, electronics, and small appliances during travel or power outages, the RIVER 2 Pro provides tremendous practical value.

The standout operational strength of the EcoFlow RIVER 2 Pro is its rapid recharge capability, which eliminates the multi-hour wait times typical of standard high-capacity power banks. Using standard alternating current from a wall outlet, the system utilizes EcoFlow X-Stream technology to charge from zero to 100 percent in just 70 minutes. This makes it easy to replenish power on short notice before bad weather strikes or during a brief stop at an RV park.

For outdoor recreation and emergency scenarios away from the electrical grid, the unit supports clean solar replenishment. With an input capacity of up to 220W of solar energy, the internal battery can be fully recharged in as little as 3.5 hours when connected to compatible solar panels in clear sunlight. The versatile multi-port output array provides 800W continuous AC delivery with transient capability up to 1600W, permitting the operation of up to 80 percent of typical consumer electronics and basic appliances.

The internal battery system utilizes premium Lithium Iron Phosphate (LFP) chemistry, which offers notable thermal stability and longevity compared to traditional lithium-ion formulations. The manufacturer rates these LFP cells for more than 3,000 full charge and discharge cycles before capacity degrades to 80 percent, translating to roughly ten years of daily or weekly use.

Operational safety is governed by an integrated Battery Management System (BMS) that actively tracks real-time operating metrics. This system oversees voltage, amperage, and internal temperatures to prevent electrical stress, overcharging, and excessive heat buildup. Paired with a robust exterior chassis and backed by a 5-year manufacturer service backing, the RIVER 2 Pro is built for dependable long-term field deployment.

The EF ECOFLOW River 3 Max Plus is an expandable portable power station and uninterruptible power supply (UPS) built to support mobile tech users, home workstations, campers, and emergency kits. This bundle pairs the 286Wh River 3 Plus base station with the EB600 572Wh extra battery, yielding a combined 858Wh of stored energy. It serves users who need reliable desktop backup power during grid failures, as well as outdoor enthusiasts who want substantial off-grid energy without carrying an oversized generator.

Charging versatility is one of this system's strongest assets. The main unit delivers 600W of continuous pure sine wave AC output, surging up to 1200W with EcoFlow X-Boost technology to manage sudden startup demands. The port array includes three UPS-protected AC outlets, two USB-A ports, a high-speed USB-C port, and a standard 12V car cigarette lighter port. In addition, attaching the EB600 module via wireless Pogo Pins unlocks a bidirectional 140W USB-C port, providing ample power to charge demanding modern laptops, tablets, and smartphones at their full supported rates.

Hardware resilience and home office utility are front and center with this model. An under-10-millisecond UPS transfer speed ensures that sensitive desktop PCs, monitors, and network-attached storage (NAS) devices remain running without rebooting during sudden blackouts. The station includes an EcoFlow USB-B to USB-A communication cable that works with PC software to safely initiate automated data saving before battery exhaustion. Internally, the unit relies on LiFePO4 cells engineered for 3,000 charge cycles before dropping to 80 percent health, housed within a fire-retardant shell rated for 3-foot drop resistance and IP54 battery splash protection.

Daily operation and replenishing the system are straightforward. Thanks to X-Stream AC charging technology, the River 3 Plus can achieve a zero-to-full charge in roughly one hour from a standard wall outlet. For off-grid power, the station accepts up to 220W of solar input, which can recharge the battery in approximately 1.5 hours in ideal sunlight. When operating appliances drawing under 100W, EcoFlow X-GaNPower efficiency keeps sound levels down to an ultra-quiet 30 dB at 1.6 feet, while Bluetooth and Wi-Fi allow complete monitoring and custom charge-rate adjustments through the mobile companion app.

While this power station is relatively compact for its capacity, buyers should keep a few practical tradeoffs in mind. The combined setup weighs around 18.5 pounds (with the base station alone weighing 10.4 pounds), making it well-suited for road trips, RV outings, and desk placement rather than lightweight backpacking. Additionally, while the 600W inverter easily powers laptops, CPAP machines, small blenders, and entertainment setups, high-draw appliances like large space heaters or hair dryers exceed its primary continuous wattage threshold.

The EF ECOFLOW River 3 Max Plus is an excellent choice for remote professionals, content creators, and emergency planners who want the security of a rapid UPS alongside an expandable, high-output outdoor power source. Shoppers seeking a tiny pocket charger will prefer a handheld power bank, but anyone needing multi-device AC and 140W USB-C backup with long-life LiFePO4 chemistry will find tremendous utility in this versatile system.

The River 3 Plus distinguishes itself from ordinary portable chargers by functioning as a high-speed uninterruptible power supply (UPS). With a transfer latency under 10 milliseconds, the inverter kicks in quickly enough to keep sensitive computer systems, gaming PCs, and home network routers running without rebooting during sudden brownouts or grid failures.

To safeguard important files and prevent data corruption, the system features a dedicated PC and NAS communication interface. Using the included USB-B to USB-A communication cable alongside EcoFlow software, connected computers can receive low-battery signals and initiate automated, safe shutdowns before the power station runs completely out of energy.

Built around durable lithium iron phosphate (LiFePO4) chemistry, the River 3 Max Plus provides 3,000 charging cycles to 80 percent capacity, representing up to a decade of daily usage. The station combines a 286Wh base unit with a 572Wh EB600 expansion module for 858Wh of total capacity, connecting seamlessly without external wires via durable Pogo Pin contacts.

Recharging options are quick and versatile. The station accepts fast AC wall power to reach a 100 percent charge in 1 hour via X-Stream technology. Users traveling off-grid can plug in up to 220W of solar panels to replenish the battery pack in roughly 1.5 hours in clear conditions, making it an adaptable power solution for cabins, RVs, and emergency outages.

The EcoFlow RIVER 2 is a compact, entry-level portable power station engineered to bridge the gap between handheld power banks and bulky emergency generators. Built for mobile device users, outdoor enthusiasts, remote field workers, and suburban emergency kits, this unit provides off-grid electrical independence in a package that fits easily into a vehicle or closet shelf. It allows users to run standard AC wall-plug devices alongside modern USB electronics without needing noisy, gas-powered machinery.

Charging capability is centered around a 256Wh lithium iron phosphate (LiFePO4/LFP) battery pack and an internal inverter providing 300W of continuous AC output, with EcoFlow rating the unit to handle up to 600W for certain essential appliances. The station supports up to six devices simultaneously through a balanced port array that includes standard 300W AC outlets, USB-C, and USB-A connections. This configuration makes it well-suited for keeping smartphones, tablets, USB-C laptops, cameras, CPAP machines, and small camping coolers energized during outdoor trips or unexpected municipal power interruptions.

In terms of physical design and durability, the RIVER 2 weighs approximately 7.7 pounds and measures 9.6 x 8.4 x 5.5 inches, presenting a solid and space-efficient rectangular profile. A sturdy rear-facing integrated carry handle enables quick one-handed transport between a vehicle trunk and a campsite picnic table. Under the hood, EcoFlow integrates an advanced Battery Management System (BMS) that constantly monitors voltage, current, and operating temperatures. The underlying LFP chemistry provides over 3,000 full recharge cycles before degrading to 80 percent of original capacity, representing nearly 10 years of routine use.

Recharging speed is one of the most practical everyday advantages of this power station. Utilizing EcoFlow's X-Stream fast-charging technology, the RIVER 2 can achieve a full zero-to-100-percent recharge from an AC wall outlet in only 60 minutes with the included charging cable. For outdoor off-grid scenarios, the unit also accepts up to 110W of solar input, capable of replenishing the battery in as little as 2.3 hours under optimal sun conditions, giving campers and field crews a sustainable way to maintain power away from civilization.

Users should be mindful of the physical and electrical boundaries inherent to this compact form factor. While 300W of continuous power easily handles consumer electronics, field displays, and small personal gear, it cannot power heavy thermal appliances such as electric skillets, hair dryers, or space heaters. Furthermore, because its 256Wh energy rating surpasses standard FAA and commercial airline carry-on allowances (typically restricted to 100Wh, or 160Wh with airline approval), this battery station is strictly suited for ground travel, road trips, camping excursions, and home preparedness rather than air travel.

The EcoFlow RIVER 2 stands out as an exceptional investment for campers, van travelers, remote digital creators, and homeowners who need a reliable, fast-recharging power station for essential devices and small appliances. Buyers looking to power heavy power tools or entire kitchen setups will need to step up to higher-wattage power stations, but those seeking long-life battery chemistry, rapid AC turnaround, and genuine 7.7-pound portability will find the RIVER 2 to be an outstanding everyday solution.

The EcoFlow RIVER 2 utilizes advanced LFP (lithium iron phosphate) battery cells, providing a substantial lifespan upgrade over traditional lithium-ion alternatives. While conventional battery packs often begin degrading after 500 charge cycles, the LFP cells in the RIVER 2 are rated for more than 3,000 complete charge and discharge cycles before capacity drops to 80 percent. This equates to nearly a decade of regular use, offering long-term reliability for frequent campers and long-term emergency preparation.

With an energy storage capacity of 256Wh and an inverter delivering 300W of continuous AC output, the station offers ample energy reserves for portable electronics. EcoFlow also incorporates power management technology that handles loads up to 600W, preventing unwanted overload shutdowns on supported devices. Integrated thermal and electrical protections continuously track current and voltage fluctuations to ensure safe power delivery across all connected mobile devices and gear.

Recharging convenience is a primary strength of the EcoFlow RIVER 2 platform. Through its integrated X-Stream technology, the unit accepts standard AC wall input via the included wall cable, accomplishing a complete 100 percent recharge in roughly 60 minutes without requiring a bulky external power brick. This allows users to top off their battery completely during a brief stop at home or an RV hookup before heading outdoors.

For remote off-grid operation, the RIVER 2 features a dedicated solar charging port that accommodates up to 110W of clean solar input. When paired with compatible portable solar panels under strong, direct sunlight, the internal MPPT controller can replenish the entire 256Wh battery pack in as little as 2.3 hours. This dual-charging flexibility ensures reliable power availability whether preparing at home or operating off the grid.

The Luvknit Solar Charger Power Bank 20000mAh is an outdoor-focused portable battery pack designed for campers, hikers, road-trippers, and emergency-preparedness kits. Built with integrated charging cables, a Qi wireless charging surface, an onboard solar panel, and dual LED flashlights, this unit targets users who want an all-in-one power reserve without packing separate loose cords. Its 20,000 mAh nominal capacity provides substantial backup power for modern smartphones, tablets, and small personal electronics away from standard electrical wall outlets.

In terms of charging performance, this battery pack supports simultaneous power delivery for up to six devices through a combination of wired and wireless connections. Physical connectivity includes three integrated cables (USB-C, Lightning, and USB-A) alongside two standard USB-A output ports and a USB-C port. The integrated Qi charging pad offers cable-free power for compatible iPhone, Samsung Galaxy, and other Qi-enabled mobile devices. While the manufacturer advertises fast-charging capability across multiple connected devices, specific per-port wattages and protocol negotiations are not published, meaning power allocation divides among connected electronics during simultaneous multi-device use.

The physical layout of the battery pack emphasizes utility for travel and outdoor recreation, measuring 6.29 by 3.34 by 0.77 inches. Its ruggedized orange casing encloses dual forward-facing LED flashlights for nighttime campsite illumination or emergency signaling. The top surface hosts the integrated solar panel, while the built-in charging cables fold neatly into dedicated channels on the casing to minimize clutter in a backpack or emergency duffel. An included mountaineering buckle lets users clip the battery pack directly to outdoor gear for hands-free transport.

Recharging the power bank can be accomplished via the USB-C input port using standard wall adapters or through the built-in solar panel under direct sunlight. Although the integrated solar panel provides an emergency charging option during extended off-grid outings, small solar surfaces naturally collect energy at modest rates. For routine everyday preparation before trips or flights, recharging the 20,000 mAh battery through a wired wall connection ensures full capacity in practical timeframes. Built-in smart protection circuitry monitors operation to guard against overcharging, overheating, and short-circuit conditions during both charging and discharging cycles.

The primary operational limitation of this power bank centers on expectations surrounding solar input and power distribution. Single-panel solar chargers of this physical size are engineered strictly as secondary emergency top-up solutions, not as primary day-to-day charging methods. Additionally, without published individual wattage ratings or Power Delivery specifications, buyers should not expect laptop charging capabilities or verified high-wattage device replenishment. Charging six devices at once will inevitably divide the available battery current, leading to slower overall charging times across all connected gadgets.

This Luvknit 20,000 mAh portable charger is best suited for outdoor enthusiasts, road-trippers, campers, and household emergency planners seeking an affordable backup battery with maximum connectivity convenience. The combination of built-in Lightning, USB-C, and USB-A cables eliminates the frustration of misplaced cords, while the dual flashlights and carabiner attachment add practical field functionality. Shoppers needing high-wattage laptop charging or ultra-compact pocket carry should look toward dedicated Power Delivery power banks, but for multi-device smartphone backup outdoors, this model offers outstanding practical utility.

Connectivity is the primary design focus of this Luvknit power bank, featuring three built-in cables alongside external ports to eliminate cable clutter. The integrated cords include a USB-C cable for modern Android devices and newer accessories, a Lightning cable for Apple iPhone and iPad devices using Lightning ports, and a USB-A cable for older electronics and power input.

In addition to the integrated cables, the housing accommodates two standard USB-A output ports and a dedicated USB-C port, allowing users to attach their own cords when needed. Combined with the surface-mounted Qi wireless charging pad, this configuration allows up to six devices to draw power at the same time, making it exceptionally functional for families, group camping, and multi-device travelers.

Designed with off-grid utility in mind, this battery pack incorporates a compact solar panel to absorb sunlight when standard wall electricity is unavailable. While solar charging on portable handheld batteries is intended for emergency trickle replenishment rather than primary routine recharging, it serves as a valuable peace-of-mind backup during unexpected outages or outdoor survival situations.

The integrated dual LED flashlights provide steady, high-visibility illumination for camping tents, night hiking, vehicle repairs, and household power failures. Combined with internal safety protections that safeguard against excessive heat, overcharging, and short-circuit risks, the unit serves as a dependable addition to home emergency kits and vehicle glove compartments.

The BLASOUL Solar Power Bank is a high-capacity external battery pack engineered specifically for outdoor recreation, emergency backup preparedness, and multi-device mobile users. Outfitted with a nominal 49,800 mAh lithium-polymer battery, built-in cables, and an integrated solar cell, this unit serves as a self-contained mobile power station. It best suits campers, hikers, road trippers, and homeowners preparing for severe weather outages who require dependable backup power without packing a tangled assortment of separate charging accessories.

Charging performance is anchored by versatile wired and wireless options, delivering up to 22.5W through supported Power Delivery 3.0 and Quick Charge 3.0 standards. The dedicated built-in USB-C cable provides up to 20W when used alone, which the manufacturer states can take an iPhone 14 up to 60 percent in approximately 30 minutes. In addition to tethered charging, the unit features an elevated 15W wireless charging pad compatible with wireless-capable devices such as recent Apple iPhone and Samsung Galaxy handsets. Buyers should note that nominal battery capacity represents internal cell storage rather than net delivered energy, as routine voltage conversion and environmental factors naturally influence usable output.

The physical casing measures 7 by 3.66 by 1.28 inches and is built to withstand demanding conditions, featuring an IP65 rating for water, dust, and shock resistance. Cable management is neatly integrated into the frame, stowing three output connectors (Lightning, USB-C, and Micro-USB) along with a USB-A input cable directly within molded channels. An ultra-bright LED flashlight is integrated into the housing, offering steady beam, SOS emergency beacon, and strobe signaling modes for nighttime campsite navigation and roadside breakdowns.

Replenishing the power bank itself can be accomplished either via an external wall adapter using the built-in USB-A lead or through compatible USB-C inputs. While the integrated solar panel provides auxiliary top-off capability when exposed to direct sunlight, solar replenishment is fundamentally slow due to the compact surface area and should be treated as an off-grid safety net rather than a daily charging method. Because of the substantial 1.28-inch profile and heavy battery mass, the charger is much better suited for storage in backpacks, dry bags, or emergency bins than everyday jacket pockets. Furthermore, because a 49,800 mAh lithium battery rating significantly exceeds standard 100Wh airline carry-on limits, air travelers should consult airline policies and avoid counting on this unit for standard commercial flight travel.

The primary limitations of this power bank stem directly from its heavy-duty capacity and ruggedized build. Everyday commuters looking for an ultralight, pocket-friendly charger will find the substantial dimensions cumbersome for quick urban transit. In addition, integrated cables cannot be individually swapped or upgraded if a single connector experiences wear over time, meaning users must handle the tethered leads carefully. Full AC wall replenishment also requires dedicated planning before heading outdoors, as relying on the solar panel alone to fill an empty battery pack of this size is impractical.

The BLASOUL 49800mAh Solar Power Bank is an excellent match for outdoor enthusiasts, remote field workers, and families assembling storm-ready emergency kits. Minimalist commuters and airline passengers will be better served by a slim, lower-capacity power bank that complies smoothly with standard flight regulations. However, for anyone needing multi-day battery reserves, broad cross-device compatibility, and all-in-one cable convenience away from electrical grids, this rugged charger offers outstanding practical value.

Wired charging speeds on the BLASOUL battery pack reach up to 22.5W via compatible PD 3.0 and QC 3.0 fast-charging protocols. The integrated USB-C cable delivers up to 20W output when used independently, offering rapid power delivery to modern smartphones, action cameras, and portable camping gadgets.

Wireless charging functionality supports up to 15W maximum output for Qi-enabled devices. Users can simply place an iPhone, Samsung Galaxy, or compatible wireless earbud case on the designated charging zone, eliminating the need to untangle cords during downtime at camp or at a work desk.

Outdoor resilience is reinforced by an IP65 weather-resistant casing designed to repel dust, splashes, rain, and minor trail impacts. The rugged exterior makes it a dependable companion for kayaking, fishing, backpacking, and unpredictable outdoor environments.

Emergency functionality is bolstered by the top-mounted LED illumination system and solar charging strip. The flashlight toggles between continuous steady light, an emergency SOS distress pulse, and a rapid strobe signal, while the built-in solar panel provides passive trickle replenishment during extended grid failures.

The SOARAISE 48000mAh Solar Power Bank is an outdoor-focused, high-capacity portable charger engineered for campers, road trippers, emergency-preparedness shoppers, and multi-device users who spend extended time away from AC outlets. Equipped with a massive 48,000 mAh lithium-polymer battery and four foldable solar panels, this unit serves primarily as a self-contained power hub. It is best suited for outdoor recreation, base camps, and severe weather backup where carrying separate cables and finding wall power are difficult.

Charging capability focuses on device versatility and simultaneous power sharing. The charger features a 5V/3A (15W) USB-C port that the manufacturer states can boost an iPhone from 15% to 60% in approximately 30 minutes, alongside two standard USB-A outputs and an integrated wireless charging pad. The system supports charging up to seven devices at the same time across its cables, ports, and wireless surface. Compatible phones include the iPhone 12 through iPhone 17 series as well as Samsung Galaxy S21 through S24 models. Buyers should understand that nominal battery capacity does not equal delivered energy to devices due to normal voltage conversion, thermal overhead, and cable resistance.

The build design emphasizes all-in-one convenience with an outdoor aesthetic. Measuring 6.38 by 3.43 by 1.57 inches, the unit combines a rugged black shell with high-visibility orange accents for quick locating in a backpack or survival tote. Rather than relying on a single small solar cell, it incorporates four fold-out solar panels that unfold to capture sunlight and snap securely against the casing for transport. Four built-in charging cables-USB-C, Phone, Micro-USB, and USB-A-tuck cleanly into molded grooves on the chassis, preventing cable tangles and ensuring support for both modern and legacy devices.

Daily operation and recharging depend on your power source and environment. While the quad-panel solar system is rated by the manufacturer to harvest energy up to five times faster than standard single-panel banks, portable solar charging remains an emergency and supplementary option rather than a quick replacement for grid electricity. For routine use, users should fully replenish the 48,000 mAh pack via wall adapter prior to leaving home, utilizing the solar panels to top off energy during sunny outdoor activities.

There are several realistic limitations buyers must consider before purchasing this model. At over 1.5 inches thick, this battery pack is noticeably bulky and unsuitable for everyday pocket carry or slim purse storage. In addition, its 48,000 mAh rating at typical 3.7V lithium-polymer voltage translates to roughly 177 Wh, which exceeds the standard 100 Wh limit set by the FAA and major international airlines for passenger carry-on bags. Furthermore, the 5V/3A charging ceiling provides standard smartphone fast charging but lacks the higher-wattage USB Power Delivery or PPS protocols required to power full-size laptops.

This solar portable charger is an outstanding choice for outdoor enthusiasts, tailgaters, road trippers, and families preparing home emergency storm kits who need high-capacity backup and total cable independence. Commuters seeking a lightweight pocket companion or air travelers needing a TSA-friendly flight charger should look toward smaller 10,000 mAh or 20,000 mAh battery packs. For off-grid resilience and multi-device camping convenience, the SOARAISE 48000mAh model offers exceptional utility in a durable package.

The SOARAISE 48000mAh Solar Power Bank delivers wide-ranging device connectivity designed to streamline mobile charging without requiring loose cords. The integrated cable array features dedicated USB-C, Phone, Micro-USB, and USB-A plugs, ensuring immediate compatibility with modern smartphones, older electronics, and rechargeable camping accessories.

Beyond the built-in cables, the power bank includes three dedicated ports: two USB-A output ports and a bidirectional USB-C input/output port rated up to 5V/3A. Together with the top-mounted wireless pad, the unit can distribute power to as many as seven connected devices simultaneously, functioning as a practical charging station for group outings and family trips.

Featuring four foldable high-efficiency solar panels, this portable charger captures sunlight up to five times faster than traditional single-panel solar banks according to manufacturer claims. The folding panel design unfolds quickly to maximize surface area under direct sun and folds flat against the body for easy packing.

While the solar panels provide valuable off-grid maintenance and emergency power during extended wilderness trips or power outages, natural solar charging speeds depend heavily on sunlight intensity and outdoor conditions. For best results, users should fully charge the battery via a wall charger before trips, using solar input to supplement power while off the grid.