Everstart Maxx 1200A Jump Starter

The day my car refused to start in the grocery store parking lot during a thunderstorm taught me a valuable lesson: being prepared is worth every penny. After that embarrassing wait for roadside assistance, I promised myself it would never happen again. Enter the Everstart Maxx 1200A Jump Starter—a device that’s become as essential to my vehicle as the spare tire. Today, I’m sharing everything I’ve learned about this portable powerhouse after two years of ownership and countless rescues (both my own vehicles and those of stranded strangers).

The Moment of Truth: How I Actually Use My Everstart Maxx

Let me walk you through my first emergency use, because it perfectly demonstrates why this device is so valuable. I had just finished a late shift at work, the parking lot was nearly empty, and temperatures had dropped below freezing. My trusty SUV—which had shown zero signs of battery issues—clicked pathetically when I turned the key.

The process was remarkably simple, even for someone like me who gets nervous around anything electrical:

1. I retrieved the Everstart Maxx from my trunk storage.
2. Flipped open the protective case and powered it on.
3. Connected the red clamp to my battery’s positive terminal, then the black clamp to the negative.
4. Waited for the green “ready” light on the jumper cables.
5. Started my engine on the first try.
6. Disconnected in reverse order (black first, then red).

The entire process took less than five minutes, and I drove home rather than waiting hours for assistance in freezing temperatures. What struck me was how simple and foolproof the device made the process—the smart clamps prevented any mistakes or dangerous situations, and clear indicator lights guided me through each step.

Power to Spare: What Vehicles Can This Thing Actually Handle?

I drive a mid-size SUV with a V6 engine, and the Everstart Maxx handles it effortlessly. But I’ve also used it to jump-start:

• My neighbor’s F-150 pickup truck
• My daughter’s compact sedan
• A friend’s diesel Volkswagen Jetta (yes, it works with diesel engines!)
• A riding lawnmower with a dead battery

The 1200A peak current is the magic number here. In practical terms, this provides enough juice to start virtually any passenger vehicle, from small compacts to large SUVs and trucks. The Everstart Maxx 1200A can reliably jump-start gasoline engines up to 8.0L and diesel engines up to 6.0L (though I’ve personally seen it work on slightly larger diesel engines in moderate weather).

What impressed me most was a situation last winter when my brother’s truck wouldn’t start after sitting unused for nearly three weeks in sub-zero temperatures. The battery was completely dead—not even dashboard lights worked. The Everstart provided enough power to bring it back to life, despite the extreme conditions and deeply discharged battery.

Charging Made Simple: How Long Until It’s Ready?

One aspect I particularly appreciate is the reasonable charging time. From completely depleted to fully charged, the Everstart Maxx typically takes:

• About 4-5 hours using the included wall charger
• Approximately 6-7 hours if charging via the 12V car adapter

The unit arrives partially charged out of the box, but I recommend a full charge before first use. An often overlooked detail is that once fully charged, the Everstart maintains its charge remarkably well. I’ve gone nearly six months between charges with minimal power loss, though I typically top it off every three months just to be safe.

The indicator lights provide a clear picture of the current charge level:

• 1 LED: 25% charged
• 2 LEDs: 50% charged
• 3 LEDs: 75% charged
• 4 LEDs: 100% charged

One charging tip I’ve discovered: while it’s tempting to leave it plugged in indefinitely, once the unit shows full charge, it’s best to disconnect it. Continuous charging for extended periods can potentially reduce the lithium battery’s lifespan.

What’s in the Box? The Complete Package

When I first unboxed my Everstart Maxx, I was pleased to find everything needed to get started immediately:

• The jump starter unit itself
• Heavy-duty smart jumper cables with spark-proof technology
• AC wall charger for home use
• DC car charger for on-the-go power
• Durable carrying case with compartments for all accessories
• User manual with clear instructions
• Quick-start guide (which proved invaluable during my first emergency use)

The build quality immediately impressed me—substantial without being unnecessarily bulky. The case has protected my unit through countless trunk shifts, camping trips, and even an accidental drop on concrete (not recommended, but mine survived without issue).

Beyond Jump Starting: Can It Actually Charge My Car Battery?

This is where I need to clarify a common misconception. The Everstart Maxx is primarily designed for jump-starting, not as a battery charger. While it delivers a powerful burst of current to start your engine, it doesn’t have the sustained output required to fully recharge a depleted car battery.

However, in practical use, I’ve found it can provide a small amount of charge to a battery that’s only slightly discharged. If your battery has enough power to illuminate dashboard lights but not enough to crank the starter, connecting the Everstart for about 15 minutes before attempting to start can sometimes help.

For actual battery charging, you’ll still want a dedicated battery charger or maintainer. I pair my Everstart with a separate trickle charger for situations requiring battery rehabilitation rather than emergency starting.

The Tech Hub: USB Charging Capabilities

One feature I use far more often than I initially expected is the USB charging functionality. The Everstart Maxx includes:

• Two USB-A ports (5V/2.1A each)
• One USB-C port (5V/3.0A)

These ports transform the jump starter into a high-capacity power bank. During a recent power outage, I used it to keep our phones charged for nearly three days. The 18000mAh capacity translates to approximately:

• 6-7 full charges for an average smartphone
• 3-4 charges for a tablet
• Multiple charges for wireless earbuds, portable speakers, or action cameras

The USB-C port is particularly useful for newer devices and offers faster charging for compatible electronics. The multi-function capability transforms this from an emergency-only device to something I use regularly, making it an even better value proposition.

Battery Specs: What’s Under the Hood?

The heart of the Everstart Maxx is its lithium-ion battery pack. With 18000mAh (66.6Wh) capacity, it strikes an excellent balance between power and portability.

For comparison, this is roughly 5-6 times the capacity of a typical smartphone battery, allowing for multiple jump starts on a single charge. In my experience, I’ve been able to jump-start four vehicles consecutively before needing to recharge.

What makes this particularly impressive is the unit’s ability to maintain peak performance in a wide range of temperatures. The lithium chemistry performs better in extreme conditions than traditional lead-acid portable jump starters, remaining operational from -4°F to 140°F (-20°C to 60°C).

Safety First: Protection Features That Matter

As someone who was initially nervous about working with car batteries, the safety features of the Everstart Maxx were a major selling point for me. The unit includes:

• Reverse polarity protection (prevents damage if you connect the clamps incorrectly)
• Over-current protection
• Short circuit protection
• Over-temperature safeguards
• Over-voltage protection
• Anti-reverse charging technology

These protections are more than marketing points—they’ve saved me from potential errors. When helping a friend jump-start his car in a dimly lit parking garage, I accidentally reversed the clamps. Instead of sparks or damage, the unit simply displayed an error light and wouldn’t deliver current until I corrected the connection.

The smart jumper cables are particularly noteworthy, featuring:

• Spark-proof connections
• Thick, well-insulated cabling
• Robust clamps that grip securely
• Built-in circuit protection

For someone who doesn’t consider themselves mechanically inclined, these safety features provide tremendous peace of mind.

Keeping It Ready: Maintenance Tips I’ve Learned

Proper maintenance ensures your jump starter will be ready when needed. My routine has evolved to include:

1. Quarterly Charging: Even if unused, I recharge the unit every three months to maintain optimal battery health.
2. Post-Use Recharging: After jump-starting a vehicle, I recharge the unit as soon as convenient, regardless of the indicated battery level.
3. Cleanliness Check: I periodically inspect the clamps and cables for dirt, corrosion, or damage. A light wipe with a dry cloth keeps the metal contacts clean.
4. Temperature Awareness: I avoid leaving the unit in extreme temperatures for extended periods. During summer, I don’t store it in the car but instead keep it in my garage.
5. Function Testing: Every few months, I power on the unit, check all functions, and test the flashlight to ensure everything works properly.

This maintenance routine takes minimal time but maximizes reliability. The one time I neglected to follow my own advice and left the unit uncharged for nearly eight months, I noticed a significant decrease in capacity—a mistake I haven’t repeated.

Warranty Coverage: What’s Protected and for How Long?

The Everstart Maxx 1200A comes with a 1-year limited warranty covering manufacturing defects and workmanship issues. While this is fairly standard for the industry, I appreciate that the warranty process is straightforward.

My experience with a minor issue (a loose USB port after about 10 months of use) was positive. The customer service team was responsive, and after providing proof of purchase and photos of the issue, they arranged a replacement unit that arrived within two weeks.

Some important warranty notes I’ve discovered:

• Keep your receipt or proof of purchase
• Register your product online when possible
• Damage from improper use isn’t covered
• The warranty doesn’t cover normal capacity degradation over time

While I would prefer a longer warranty period (some premium jump starters offer 2-3 years), the overall reliability of the unit has made this a minor concern in practice.

Weather Warriors: Performance in Extreme Conditions

Living in an area with both scorching summers and freezing winters, I’ve tested the Everstart in a wide range of conditions. Its performance has consistently impressed me.

In winter conditions (as low as -15°F/-26°C), the unit has successfully started vehicles when other portable jump starters failed. The lithium technology maintains power delivery capability in cold weather far better than lead-acid alternatives.

During summer heat waves (up to 105°F/40°C), I’ve noticed only minimal impact on performance, though I try to keep the unit out of direct sunlight to prevent overheating.

One particularly memorable use was during a blizzard when my vehicle wouldn’t start after being parked outside overnight in heavy snow. Despite being stored in the cold vehicle, the Everstart had enough power to start my engine on the first attempt.

For extreme weather use, I recommend:

• Bringing the unit to room temperature before charging it
• Storing it in a moderate-temperature environment when possible
• Keeping it in the carrying case to provide insulation against temperature extremes
• Allowing a cold unit to warm slightly before attempting a jump-start in freezing conditions

Troubleshooting: Solutions to Common Issues

Over my years of ownership and helping others with their units, I’ve encountered several common issues and developed reliable fixes:

Issue: Unit won’t power on

• Solution: Press and hold the power button for 3-5 seconds
• Solution: Connect to a charger for at least 30 minutes, then try again
• Solution: Perform a reset by holding the power button for 10 seconds

Issue: Jump-start function doesn’t work despite full charge

• Solution: Ensure clamps have good, clean contact with battery terminals
• Solution: Check that the vehicle’s battery isn’t completely dead (some voltage is needed)
• Solution: Wait 30 seconds after connecting clamps before attempting to start
• Solution: For stubborn starts, connect the unit, wait 2-3 minutes to allow some charge to transfer, then attempt starting

Issue: USB ports not charging devices

• Solution: Try a different USB cable
• Solution: Press the power button twice to activate USB charging mode
• Solution: Check that the device being charged is compatible with the provided amperage

Issue: LEDs indicate charging but unit never reaches full charge

• Solution: Try a different charging cable or adapter
• Solution: Allow 6-8 hours for a complete charge
• Solution: If persistent, the battery may be degrading and approaching end-of-life

My most useful troubleshooting tip: when in doubt, consult the manual. The troubleshooting section contains specific error codes and their meanings that can save significant time and frustration.

The Numbers Game: Understanding Peak Amperage

The “1200A” in the product name refers to the peak amperage—the maximum current the unit can deliver in short bursts. This specification is crucial for jump-starting, as vehicle starters require a significant current surge to turn over the engine.

In practical terms, the 1200A rating is more than sufficient for most vehicles, including:

• Compact and mid-size cars (typically require 400-600A)
• SUVs and light trucks (typically require 600-800A)
• Larger trucks and diesel engines (typically require 800-1000A)

What I’ve learned is that the cranking amps (CA) or cold cranking amps (CCA) ratings are more relevant for consistent performance than peak amps. The Everstart delivers approximately 400-500 CCA, which explains its reliable starting capability even in cold weather.

One important note: the 1200A rating represents ideal conditions. Factors that can reduce effective amperage include:

• Low charge level in the jump starter
• Extreme temperatures (particularly cold)
• Age of the unit (capacity naturally decreases over time)
• Poor connections at the battery terminals

Charging Indicators: How to Know When It’s Ready

The Everstart Maxx features a straightforward LED indicator system for charge status:

• During charging: LEDs flash sequentially to show charging progress
• When fully charged: All four LEDs remain solid
• During use: LEDs show remaining capacity (4 = 76-100%, 3 = 51-75%, 2 = 26-50%, 1 = 1-25%)

One subtle detail I’ve noticed is that the last 10% of charging takes disproportionately longer than the first 90%. This is normal for lithium batteries and reflects the battery management system’s balancing process to ensure cell longevity.

For optimal battery health, I’ve found it best to disconnect from the charger within an hour of reaching full charge, though occasional overnight charging hasn’t caused any noticeable issues with my unit.

Beyond Vehicles: Powering Small Appliances

While primarily designed for vehicle jump-starting, the Everstart Maxx can power various small appliances and devices through its USB ports. I’ve successfully used it to power:

• LED camping lights (ran for nearly 20 hours)
• A small USB fan during a summer power outage
• A CPAP machine for emergency use (though only for a few hours)
• Various rechargeable tools with USB charging capabilities

The 18000mAh capacity translates to approximately 66 watt-hours of energy, which provides context for potential run times. For example:

• A 10W device can run for about 6 hours
• A 20W device can run for about 3 hours
• A 5W device can run for about 12 hours

It’s worth noting that the Everstart Maxx does not have an AC inverter, so it cannot directly power standard household appliances that require wall outlets. For such applications, you would need a dedicated portable power station with inverter functionality.

Competitive Landscape: How It Stacks Up

I researched extensively before choosing the Everstart Maxx, and having now used it for years, I can confidently compare it to alternatives:

Compared to NOCO Boost Plus GB40 (1000A)

• The Everstart offers higher peak amps (1200A vs 1000A)
• The NOCO has a slightly more compact design
• The Everstart provides better value at typically 20-30% lower cost
• Both offer similar safety features and reliability

Compared to STANLEY J5C09 (1000A)

• The Stanley uses lead-acid technology (heavier, larger)
• The Everstart’s lithium battery holds charge longer when stored
• The Stanley includes an air compressor (handy but adds bulk)
• The Everstart performs better in cold weather

Compared to Schumacher SL1397 (1200A)

• Similar performance specifications
• The Everstart typically costs less
• The Schumacher includes a slightly longer warranty
• Both offer comparable safety features

After extensive use, I believe the Everstart Maxx 1200A hits the sweet spot of performance, features, and value. While premium brands might offer incremental improvements in build quality or additional features, the core functionality remains comparable at a significantly higher price point.

Where to Buy: Finding the Best Deal

The Everstart Maxx 1200A is primarily sold through Walmart as it’s their house brand for automotive accessories. This exclusivity actually simplifies the purchasing process and typically ensures consistent pricing.

I purchased mine in-store during an automotive department sale, but they’re regularly available:

• In Walmart’s automotive section
• On Walmart’s website
• Occasionally through third-party marketplace sellers (though I recommend buying directly from Walmart for warranty purposes)

Pricing typically ranges from $79-99 depending on sales and promotions. I’ve noticed seasonal patterns in pricing, with the best deals often appearing:

• During major holiday sales (Black Friday, Memorial Day, etc.)
• Early winter (November-December) when battery issues become common
• During automotive department promotions

If purchasing in-store, I recommend checking the manufacturing date (usually printed on the box) and selecting the newest production available, as this ensures the maximum battery lifespan.

Safe Storage: Keeping Your Jump Starter Ready

Proper storage is crucial for maintaining your jump starter’s performance and longevity. My approach includes:

1. Location Considerations: I store mine in a cool, dry place—typically in my garage on a shelf rather than in my vehicle where temperature extremes can affect battery life.
2. Charge Level: I ensure it’s at least 50% charged before storing for extended periods (lithium batteries prefer partial charge for long-term storage).
3. Case Usage: I always keep it in the provided carrying case, which offers protection against dust, moisture, and minor impacts.
4. Cable Management: I neatly coil the jumper cables to prevent strain at connection points and ensure the clamps don’t contact each other.
5. Accessibility Balance: I store it somewhere accessible enough for quick retrieval in emergencies but protected from curious children (the jumper clamps should be treated with appropriate caution).

During road trips or when traveling in remote areas, I do keep the unit in my vehicle, accepting the minor battery degradation risk in exchange for guaranteed accessibility when potentially needed most.

Common Problems: Issues to Watch For

After extensive personal use and conversations with other owners, I’ve identified several recurring issues worth monitoring:

Battery Degradation Over Time
All lithium batteries eventually lose capacity. After about two years of regular use, I’ve noticed approximately 15-20% reduction in total capacity—still more than enough for jump-starting but with fewer available device charges.

Clamp Deterioration
The metal contacts on the jumper clamps can corrode over time, especially if exposed to moisture or battery acid. I inspect these regularly and clean them with a wire brush if needed.

Charging Port Wear
The micro-USB charging port (on older models) or USB-C port (on newer versions) can become loose after repeated use. I’m careful to avoid yanking the cord and ensure proper alignment when connecting.

Cold Weather Performance Reduction
While better than lead-acid alternatives, extreme cold still impacts performance. I’ve noticed approximately 30% reduced capacity when using the unit in sub-zero temperatures.

Case Zipper Failure
Several users report zipper issues on the carrying case after 1-2 years. While not affecting functionality, it’s a minor annoyance. I reinforce the zipper stops with a few stitches of heavy thread as preventative maintenance.

Diesel Compatibility: Yes, But With Caveats

The Everstart Maxx 1200A is indeed compatible with diesel engines, but with some important qualifications:

• It reliably jump-starts diesel engines up to about 6.0L in displacement
• Cold weather significantly impacts performance with diesel engines
• Heavily discharged diesel batteries may require multiple attempts
• Glow plug systems draw additional current and may require a pre-warming cycle

My experience with diesel vehicles has been generally positive. I’ve successfully jump-started:

• A 2.0L Volkswagen diesel sedan (easily, even in cold weather)
• A 3.0L diesel SUV (started on first attempt)
• A 6.7L diesel pickup (required connecting the jump starter, waiting about 3 minutes, then attempting to start)

For larger diesel engines, especially in cold weather, I recommend:

1. Ensuring the jump starter is fully charged
2. Connecting the unit and waiting 2-3 minutes before attempting to start
3. Cycling the ignition to “ON” position for 10 seconds before cranking to allow glow plugs to warm
4. If the first attempt fails, waiting 5 minutes between attempts to allow the jump starter to recover

My Final Verdict: Is It Worth It?

After two years of ownership and dozens of uses (both emergency and convenience), I can confidently say the Everstart Maxx 1200A has exceeded my expectations and earned its place in my essential vehicle equipment.

What I Love:

• Reliability when it matters most
• Intuitive operation even under stress
• Versatility beyond jump-starting
• Excellent value compared to premium brands
• Compact size that doesn’t sacrifice performance

What Could Be Improved:

• Longer warranty period
• More durable carrying case
• Additional charging options (wireless charging pad would be nice)
• Better cold weather performance rating

When I calculate the value proposition—factoring in the cost of even a single roadside assistance call, the convenience of not waiting for help, and the additional USB charging functionality—the Everstart Maxx 1200A Jump Starter is perhaps the best automotive investment I’ve made. It delivers genuine peace of mind that extends beyond my vehicle to knowing I can help others in need.

Whether you’re a daily commuter, weekend adventurer, or someone who simply prefers self-reliance, this jump starter offers capability and convenience that makes it an essential addition to your vehicle preparedness kit. Just remember to keep it charged, store it properly, and it will be ready when you need it most—which is exactly when such reliability matters.