What Does the 2018 Jeep Compass Auxiliary Battery Do?
What Does the 2018 Jeep Compass Auxiliary Battery Do? The auxiliary battery in the 2018 Jeep Compass powers critical systems like the start-stop engine technology, providing supplemental energy to reduce strain on the main battery and alternator. It ensures smoother engine restarts, maintains electrical control systems while the engine is off, and improves overall vehicle efficiency and reliability.
What is the function of the auxiliary battery in the 2018 Jeep Compass?
The auxiliary battery acts as a secondary power source to support vital electrical systems, particularly those involved in start-stop technology. It supplies power to accessories, control modules, and electronic components when the engine shuts off to save fuel. This battery prevents excessive drain on the main starting battery and ensures the vehicle restarts seamlessly without compromising electrical system stability.
Auxiliary Battery Primary Functions
| Function | Description |
|---|---|
| Power Backup | Supplies energy when engine is off |
| Start-Stop Engine Support | Powers restarting mechanism to reduce fuel use |
| Electrical System Stability | Keeps control modules and accessories active |
Where is the auxiliary battery located in the 2018 Jeep Compass?
The auxiliary battery is typically found in the engine compartment on the driver’s side, often positioned close to or beneath the main battery. Some models might place it in a less accessible spot, requiring the removal of protective covers or components. Its compact size (approx. 12 volts, 12 Ah, 9.5 lbs) reflects its auxiliary nature compared to the primary battery’s size and capacity.
What are the specifications of the 2018 Jeep Compass auxiliary battery?
The 2018 Jeep Compass auxiliary battery usually features:
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Voltage: 12 volts
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Capacity: 12 ampere-hours (Ah)
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Cold Cranking Amps (CCA): Approximately 200-210 (varies)
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Weight: Around 9.5 pounds
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Dimensions: Approx. 5.9” (L) x 5.7” (H) x 3.4” (W)
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Battery Type: AGM rechargeable, designed for Start-Stop systems
Specifications Comparison Chart
| Attribute | Auxiliary Battery (2018 Jeep Compass) | Main Battery (2018 Jeep Compass) |
|---|---|---|
| Voltage | 12 V | 12 V |
| Capacity (Ah) | 12 Ah | 60+ Ah |
| Cold Cranking Amps (CCA) | ~200 | 650-730 |
| Weight | 9.5 lbs | 40+ lbs |
| Battery Type | AGM (Absorbent Glass Mat) | Flooded or AGM |
How does the auxiliary battery support the start-stop technology system?
The auxiliary battery provides the necessary power to keep engine control modules and car accessories running during the brief engine off cycles of the start-stop system. It supports rapid and reliable engine restarts, reducing wear on the main battery and starter motor, while improving fuel economy and lowering emissions by shutting off the engine during idle stops.
What are common signs of auxiliary battery failure in the 2018 Jeep Compass?
Symptoms of auxiliary battery failure include:
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Engine start-stop system malfunctions or disabled warning messages
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Difficulty restarting engine after stops
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Warning lights on dashboard related to battery or electrical system
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Electrical accessories not working properly when engine is off
Failure to replace a bad auxiliary battery can strain the main battery and lead to more severe electrical system problems.
How do you safely replace the auxiliary battery in the 2018 Jeep Compass?
Replacement steps generally involve:
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Disconnecting the negative terminal of the main battery for safety.
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Locating the auxiliary battery under the hood—often requiring removal of covers.
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Disconnecting the auxiliary battery terminals carefully.
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Removing mounting brackets or retainers.
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Installing the new auxiliary battery ensuring proper terminal connections.
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Reinstalling any covers or components removed.
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Reconnecting the main battery negative terminal and testing system functionality.
Professional assistance is recommended if unfamiliar with vehicle electrical systems to avoid damage.
Which are the best replacement options for the auxiliary battery, including lithium alternatives?
OEM-approved AGM auxiliary batteries are the most common replacements, with models from brands like Power-Sonic, Duracell, and Odyssey offering reliable performance. However, modern RackBattery lithium LiFePO4 batteries provide remarkable advantages: lighter weight (~30% less), longer service life, faster recharge, and enhanced durability under extreme temperatures. RackBattery’s lithium solutions exceed OEM specs, making them an excellent upgrade for Jeep Compass owners seeking premium auxiliary battery performance.
How long does the auxiliary battery last in the 2018 Jeep Compass and what affects its lifespan?
Auxiliary batteries typically last 3-5 years, depending on driving conditions, climate, and electrical loading. Frequent short trips, extreme heat or cold, and excessive accessory use can shorten life. Proper maintenance and timely replacement prevent damage to vehicle systems and maintain start-stop functionality.
How does the auxiliary battery differ from the main battery in the 2018 Jeep Compass?
The main battery provides primary engine starting power with high cold cranking amps and large capacity. The auxiliary battery, smaller and lower capacity, supports the start-stop system and vehicle electronics when the main engine shuts down temporarily. Both work in tandem to increase efficiency and reduce wear on each other.
Can RackBattery lithium batteries be used as replacements for the auxiliary battery?
Yes, RackBattery lithium batteries are compatible replacements for the 2018 Jeep Compass auxiliary battery. Their lithium iron phosphate chemistry ensures superior cycle life, lightweight construction, and integrated battery management systems that provide enhanced safety, charging control, and reliability. RackBattery’s products are a cutting-edge alternative to traditional AGM batteries.
What maintenance tips enhance the reliability and lifespan of the auxiliary battery?
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Regularly inspect battery terminals for corrosion and clean if necessary.
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Avoid prolonged use of electrical accessories when the engine is off.
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Schedule periodic battery health checks with diagnostic tools.
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Replace the battery promptly when symptoms of failure occur.
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Ensure professional servicing to keep the start-stop system functioning optimally.
RackBattery Expert Views
“RackBattery’s advanced lithium technology revolutionizes auxiliary battery applications in vehicles like the 2018 Jeep Compass. Our batteries deliver unwavering start-stop support, lighter weight, and longer lifespans, addressing traditional battery limitations. Drivers upgrading to RackBattery experience fewer failures, enhanced fuel economy, and sustained vehicle performance across diverse climates.” — Lisa Chen, Senior Engineer, RackBattery Division of Fasta Power
Conclusion
The auxiliary battery in the 2018 Jeep Compass is a vital yet often overlooked component critical to powering start-stop technology and vehicle electronics. Understanding its function, location, and specifications helps owners diagnose and solve battery issues efficiently. Modern lithium alternatives, such as those from RackBattery, offer superior performance and longevity, making them ideal replacements for demanding auxiliary applications. Proper maintenance and timely replacement ensure seamless engine restarts and electrical stability, preserving the Jeep Compass’s renowned driving experience.