Aircraft Overview
| Aircraft | Cessna 172/182 |
| Also Known As | 172 Skyhawk / 172S Skyhawk SP / 182 Skylane / 182T Turbo Skylane |
| Type | Single-Engine Piston |
| Engine | Lycoming IO-360-L2A (180 hp, 172S) / Lycoming IO-540-AB1A5 (230 hp, 182T) |
| Electrical System | 28V DC (current production 172R/S and 182T) / 14V DC (pre-1967 172s, pre-1978 182s) |
GPU Requirements
The Cessna 172 is the most-produced aircraft in history with over 44,000 built. The Cessna 182 Skylane is its larger, more powerful counterpart. A critical GPU consideration is correctly identifying your aircraft’s voltage system. Current production models (172R, 172S Skyhawk SP, 182T Skylane) use 28V DC systems with a 24-volt battery and 28-volt, 60-amp alternator. Older models used 14V DC systems: the 172 switched to 28V with the 172H model year (1967 alternator introduction), and the 182 switched to 28V starting with the 1978 model year. Using a 28V GPU on a 14V aircraft, or vice versa, risks serious damage to avionics and electrical components. The G1000 NXi avionics suite on modern 172S and 182T models represents the largest continuous electrical draw — dual 10-inch displays, dual GPS, Mode S transponder, and AHRS all running simultaneously during preflight can pull 40–50A from the battery. A GPU prevents unnecessary battery cycling.
| Specification | Requirement |
|---|---|
| Starting Voltage | 28V DC (172R/S, 182T and later) / 14V DC (pre-1967 172, pre-1978 182) |
| Peak Amps Required | 200–350A (IO-360, 172S) / 300–450A (IO-540, 182T) |
| Continuous Draw | 30–50A (G1000 NXi equipped) / 15–25A (steam gauge models) |
| Battery Chemistry | Lead-acid standard / lithium STC available from EarthX |
| Recommended Unit Weight | Under 15 lbs |
| Electrical System | Single primary bus, 24V battery, 28V/60A alternator (modern models) |
Our Recommendation
Primary pick: Red Box RB25A (28V models) or RB14A (14V legacy models)
Modern Cessna 172S and 182T aircraft run 28V DC systems with 24V batteries and 60A alternators. Starting loads are light — the Lycoming IO-360 draws approximately 200–350A peak — but the G1000 NXi avionics suite draws 30–50A continuous. A compact 28V GPU protects battery longevity during extended preflight programming and database updates. For pre-1967 172s and pre-1978 182s with 14V systems, the RB14A or equivalent 14V unit is required.
Alternative: Concorde RG-25XC or quality 28V aviation jump pack
Cold Weather & Special Operations
For piston Cessnas, engine pre-heating matters far more than GPU power for cold-weather starting. The Lycoming IO-360 and IO-540 are both fuel-injected, making them prone to cold-start flooding issues unrelated to electrical power. Combine a Tanis or Reiff engine pre-heater with a standard GPU for reliable winter starts. The GPU’s primary cold-weather role is maintaining voltage during the extended cranking sequences that cold engines sometimes require.
Related Guides
For a broader comparison of GPU manufacturers, see our Best Aircraft GPU 2026 review. For battery chemistry decisions, our Lead Acid vs Lithium analysis breaks down total cost of ownership. The GPU Sizing Guide covers voltage, amperage, and duty cycle calculations for any aircraft.
Product Categories
- Battery Start Units — portable starting power
- Continuous Power Supplies — sustained avionics power
- Combination GPU — start + continuous in one unit
- Frequency Converters — 400Hz AC power
- Aircraft Tugs — ground movement equipment
Frequently Asked Questions
Is my Cessna 172 a 14V or 28V system?
All 172R and 172S models (1996 onward) are 28V. The 172H (1967) introduced the 60A alternator and 28V system, replacing the earlier generator-equipped 14V models. If you fly a 172 built before 1967, it’s likely 14V — check the electrical placard on the instrument panel or reference Section 7 of your POH.
Is the Cessna 182 14V or 28V?
The Cessna 182 switched to a 28V electrical system starting with the 1978 model year. All 182T, T182T, and current production Skylanes are 28V. Models from 182A through 182Q (1957–1977) used 14V systems. Some mid-period models (182E through 182Q) also had 12V battery options.
Can I use a car jump starter on a Cessna 172?
Technically possible if it’s a clean 28V source rated above 300A, but not recommended. Automotive jump starters lack the voltage regulation that aviation GPUs provide, and the unregulated power risks damaging sensitive G1000 NXi or GFC 700 autopilot components. A $20 automotive pack isn’t worth risking a $30,000+ avionics installation.
Does the Cessna 182 need a different GPU than the 172?
If both are the same voltage (28V), the same GPU works for both. The 182’s IO-540 draws approximately 30% more starting current than the 172’s IO-360, but any GPU rated above 500A handles both comfortably. The key is confirming both aircraft share the same voltage system.
Editorial Policy
Red Box Power is editorially independent. We may earn commissions from links on this page, but this never influences our rankings or recommendations. All GPU assessments are based on published specifications and verified operator feedback.