How We Evaluated
This review covers portable and semi-portable ground power units in the 12V–28V DC range — the equipment category that serves general aviation, business aviation, rotorcraft, and light military operations. We do not cover large fixed-installation 400Hz frequency converters or diesel-powered mobile GPUs in this guide, as those serve a fundamentally different operational profile. For 400Hz equipment, see our frequency converter directory.
Each manufacturer was evaluated across 14 criteria: peak starting amps, continuous output capability, battery chemistry options, weight-to-power ratio, voltage regulation accuracy, cold-weather starting performance (tested or documented below -20°C), charge time, cycle life rating, build quality and environmental protection rating, connector compatibility, warranty terms, after-sales support availability, geographic distribution network, and total cost of ownership over a 5-year period.
We relied on published manufacturer specifications, publicly available test data, distributor documentation, and maintenance community feedback. We did not receive review units, compensation, or advance access from any manufacturer. Where specifications could not be independently verified, we note the limitation.
Red Box Aviation
Red Box Aviation has been manufacturing ground support equipment since 1993, originally from facilities in southern England. In 2024, the company was acquired by LPA Group, an engineering specialist in power connectors and electromechanical systems for aviation, rail, and industrial markets. The acquisition has expanded Red Box's manufacturing capabilities and distribution reach without significantly altering the product line.
Red Box offers the widest range of any manufacturer in this review. The product catalog spans battery start units from 12V to 28V in both lead-acid and lithium configurations, mains-powered continuous DC supplies from 25A to 600A, combination start-and-continuous units, and transformer rectifier units capable of 3,000A peak output. This breadth makes Red Box the default choice for operators who want a single supplier across their entire ground power infrastructure.
Strengths
Broadest product range in the industry. NATO codification on most units simplifies military procurement. The RBSC continuous power supply line is specifically engineered for high-use MRO and military environments with precise voltage regulation. Strong international distribution network through authorized dealers. The aircraft search tool on their website helps match specific aircraft models to compatible GPUs — a useful feature that no other manufacturer replicates as effectively.
Limitations
Pricing tends to sit at the premium end of the market. Lead times can be extended for custom-configured or less common models. The 2024 acquisition by LPA Group introduces a transitional period that some operators have noted affects responsiveness, though the company states operations continue as normal.
Start Pac
Start Pac has been manufacturing portable ground power equipment in the United States since 1997. The company specializes in portable starting units, combination GPU/power supplies, and the patented Quick Change battery system that allows field replacement of battery modules in under 60 seconds without tools. The product line covers 24V and 28V configurations for aviation, as well as units for locomotive, military, and heavy machinery applications.
Start Pac's key differentiator is the Quick Change system. In operations where downtime cannot be tolerated — medevac, military, or high-volume FBO environments — the ability to swap a depleted battery module for a fresh one in seconds rather than waiting for a recharge cycle is a genuine operational advantage that no other manufacturer in this review offers.
Strengths
Quick Change battery system is unique in the industry. Lithium units weigh 42% less than equivalent lead-acid models. Strong customer support and a 30-day money-back guarantee. American-made with ISO 9001 certification. The GREEN GPU model is the first 100% emission-free autonomous ground power unit — significant for operators facing airport sustainability mandates. Lifetime trade-in program for older units adds long-term value.
Limitations
Lower peak starting amps compared to Red Box's largest units. Primarily focused on portable and semi-portable equipment — does not offer fixed-installation TRUs or 400Hz frequency converters. Battery warranty treats batteries as consumable items, which may not be covered under the standard warranty if damage occurs from misuse.
Powervamp
Powervamp is the only UK-based manufacturer in this review that designs and produces both 28V DC battery carts and 400Hz frequency converters under one roof. Based in Somerset, England, the company has been manufacturing ground power equipment since the early 2000s and has built a particular reputation for its Coolspool range of 28V DC battery carts and its solid-state frequency converter installations at major international airports.
Strengths
Only UK manufacturer covering both DC and 400Hz from a single product line. The Coolspool range has won industry awards for its combination of environmental performance and starting capability. The JetGo 300 continuous power unit is specifically designed for regional DC operators. Strong on sustainability — the entire Coolspool range is positioned as a cost-saving, environmentally friendly alternative to diesel GPUs.
Limitations
Smaller distribution network compared to Red Box or Start Pac. Higher price point on 400Hz equipment relative to ITW GSE's equivalent solid-state units. Less presence in the US market than American-manufactured alternatives.
StartStick
StartStick entered the market in 2014 and has rapidly established itself as the dominant player in the ultra-portable GPU segment. With over 2,500 units deployed globally — including adoption by Airbus, US Special Operations Aviation, US Air Force, and allied military forces — the product has achieved the kind of institutional validation that typically takes decades.
The core proposition is extreme portability. StartStick GPUs weigh between 10 and 20 pounds, feature single-button operation, and are designed to be stowed inside the aircraft rather than maintained as separate ground support equipment. For helicopter operators in particular, the ability to carry a GPU onboard eliminates the single largest operational constraint of remote field starts: dependency on ground equipment that may not be available at the destination.
Strengths
Lightest GPU in the market by a significant margin. Military-grade certification (MIL-STD-810H) for shock, vibration, and environmental resistance. Single-button operation eliminates training overhead. Patented integrated design combines battery, connector, and carrying handle into one unit. NATO 3-pin connector compatibility across most common military and GA aircraft. Proven in the most demanding operational environments on the planet.
Limitations
Limited to engine starting only — does not provide continuous power for extended maintenance. Capacity is sufficient for 1-3 starts depending on aircraft type, not for high-volume FBO operations requiring dozens of starts per day. Premium pricing for what is functionally a single-purpose device. Only available in 28V — operators with 12V or 14V aircraft need to look elsewhere.
Audio Authority (White Lightning)
Audio Authority's White Lightning line occupies a unique position in the market: affordable, well-built GPUs aimed at owner-operators and small maintenance shops rather than commercial or military buyers. The product range covers both 14V and 28V configurations, with prices starting significantly below the premium manufacturers — the entry-level 14V experimental aircraft model retails for $475.
Aviation Consumer magazine's 2024 portable ground power roundup awarded Audio Authority the top recommendation among the GPUs tested, citing build quality, stable voltage output, and value for money. The units use aerospace-grade components with torch-soldered, silver-plated connections and heavy-gauge output cables (up to 0 AWG wire delivering up to 1,600A peak).
Strengths
Best value-for-money in the market. Aerospace-grade construction at consumer pricing. Available through Aircraft Spruce and Sporty's — the two retailers most GA owner-operators already use. Automatic shutdown timer prevents battery drain if left connected. Available in 14V for experimental and 12V aircraft, a segment that most premium manufacturers ignore. Aircraft jumper cable accessory ($163) allows car-battery jump starts in emergencies.
Limitations
Lower continuous output than professional-grade units. Not certified to military standards. No lithium battery options currently available. Limited to the GA and experimental market — not suitable for commercial MRO or high-volume operations.
Tronair
Tronair approaches ground power from the GSE side rather than the battery manufacturer side. As one of the largest ground support equipment manufacturers globally, Tronair's GPU product line sits within a broader catalog of jacks, towbars, lavatory carts, and service equipment. The company offers both portable and mobile GPU configurations across the voltage range, with particular strength in the commercial aviation segment.
Strengths
Broadest GSE catalog in the industry — operators who standardize on Tronair for their wider GSE fleet can consolidate GPU procurement under the same vendor. Strong in the commercial aviation segment. Global service network. Towable mobile units serve the bridge-gate environment where portable packs are insufficient.
Limitations
GPU is not Tronair's primary focus — the company is a generalist GSE manufacturer rather than a power specialist. Less depth in the portable/battery segment compared to dedicated GPU manufacturers. Pricing requires direct quotation — less transparent than manufacturers who publish retail prices.
Head-to-Head Comparison
The following comparison focuses on the portable 28V DC battery start unit category, as this is the segment where all six manufacturers compete directly and where most purchasing decisions are made.
Not sure what voltage or amperage you need? Our GPU Sizing Guide walks through the calculation step by step, or browse our aircraft-specific recommendations for model-matched GPU suggestions.
Our Recommendations
Best Overall — Red Box Aviation
For operations that need a single supplier across multiple power categories — starting, continuous, combination, and TRU — Red Box Aviation remains the most comprehensive choice in 2026. The product range is unmatched, the NATO codification simplifies military procurement, and the international distribution network ensures parts and support are accessible globally. The LPA Group acquisition has strengthened rather than disrupted the business.
Best for High-Volume Operations — Start Pac
FBOs processing dozens of starts per day benefit most from Start Pac's Quick Change system. The ability to swap battery modules in under 60 seconds eliminates recharge-related downtime entirely. The GREEN GPU model adds a zero-emission option for operators facing sustainability mandates. American manufacturing and the lifetime trade-in program make this the best long-term value for professional users.
Best Portable — StartStick
For helicopter operators, remote field operations, and military applications where every pound matters, StartStick is the clear winner. At 10–20 lbs with MIL-STD-810H certification, it eliminates the need for ground-side equipment entirely. The $995–$1,445 price point is justified by the operational flexibility it creates.
Best Value — Audio Authority White Lightning
Private aircraft owners and small maintenance shops that need a reliable, well-built GPU without professional-grade pricing should look at Audio Authority's White Lightning line. Starting at $475 with aerospace-grade construction, it delivers more quality per dollar than anything else in the market. Available through Aircraft Spruce and Sporty's for convenient purchasing.
Frequently Asked Questions
What is the best aircraft ground power unit in 2026?
The best GPU depends on your operation. For portable engine starting, Red Box Aviation and Start Pac lead with lithium and lead-acid options across the widest range. For fixed-installation continuous power, Powervamp and ITW GSE offer the most comprehensive solid-state ranges. StartStick is the top choice for ultra-portable field use under 20 lbs.
How much does an aircraft ground power unit cost?
Portable battery start packs range from $475 for basic 14V units (Audio Authority) to $3,000+ for high-capacity lithium 28V packs (Red Box, Start Pac). Mains-powered continuous supplies range from $1,500 to $8,000. Fixed-installation TRUs and 400Hz frequency converters can exceed $20,000 depending on power rating and configuration.
Should I buy a lead acid or lithium GPU?
Lithium GPUs weigh 40–50% less and last roughly twice as many charge cycles, but cost 2–3x more upfront. For daily use in professional maintenance environments, lithium's lower total cost of ownership typically wins over a 5-year horizon. For occasional use by private owners (fewer than 50 starts per year), lead acid remains the cost-effective choice. See our full Lead Acid vs Lithium analysis for detailed cost modeling.
What voltage GPU do I need for my aircraft?
Most certified aircraft with 24V electrical systems require a 28V DC GPU. Older or experimental aircraft with 12V systems need a 14V DC unit. Commercial jets and large turboprops require 400Hz AC power at 115V or 200V. Check your aircraft's POH or maintenance manual for specific external power requirements, or use our aircraft-specific GPU finder for model-matched recommendations.
This guide is part of our technical reference series. Related reading: Lead Acid vs Lithium Cost Analysis · GPU Sizing Guide · TRU Specification Guide · Complete Equipment Directory