Best Battery Charger for Your Boxster

If you plan on ever parking your Boxster for more than 3 weeks, you will need the Best Battery Charger for your Porsche Boxster.

A major concern when parking, winterizing or storing your Porsche Boxster is the draining of the car battery. The car battery will eventually die due to parasitic draining.

Porsche Battery Bosch AGM
Save Your Battery

Why You Need Best Battery Charger for your Porsche Boxster?

Boxsters are not very user friendly if your battery dies. In fact, you cannot even get access to the battery unless you have a spare battery sitting around. You need to prevent parasitic draining of your battery.

Parasitic Battery Draining

A parasitic battery drain happens when an abnormal and continuous discharge of power occurs after having shut off the engine. This can happen in your Boxster in as little as 3 weeks. Porsche recommends charging your battery if you plan on not driving it for 6 weeks.

Battery charging
Automotive batteries lose their efficiency when not in use.
The charge available in your battery can be measured with a battery hydrometer.
We recommend that the battery voltage be tested by your authorized Porsche dealer who has the appropriate equipment.
If the car is not driven for prolonged periods, the battery must be charged at least every 6 weeks. A discharged battery allows rapid formation of sulfates, leading to premature deterioration of the

Porsche Boxster Owner’s Manual

The Cause of Parasitic Battery Draining:

  • Short circuit in your wiring
  • Incorrectly installed car power accessory (i.e. Radar Detector, Laser Jammer, etc.)
  • Defective alternator
  • Old battery or in poor condition
  • Corroded or loose battery cables
  • Extreme temperatures (over 100 degrees Fahrenheit) or cold (under 10 degrees Fahrenheit)
  • Excessive Short Drives
  • Human error (dome light or headlights left on, etc.)

Failure to heed this warning will result in a dead battery.

Help I Have a Dead Battery!

If you have a dead battery and need to open the front luggage compartment to gain access to the battery. This will be the process to jump-start your Boxster, but it will not be easy or straight forward. Thus the best process is the knowledge of the existence of this issue and the application of using a battery charger to prevent a dead battery from occurring.

Dead battery and Can’t Open Hood

Your Battery is located in the “frunk” (front luggage compartment.) If your battery becomes discharged, it will result in you not being able to access your front luggage compartment. Your key fob will not work, nor with the electric switches located inside the car.

As a result, a dead battery will prevent the front luggage compartment lid from opening to access your battery. That is without the aid of a donor battery!

How to Unlock the Hood with a Dead Battery

Critical Note: You cannot start the engine with this method, This process is for late 986 and 987/987.2 models. And, This entire process is located in the owner’s manual.

  1. Firstly, unlock the driver’s side door and open it.
  2. Secondly, remove the plastic cover from the fuse box (located in the driver-side footwell.
  3. Pull out positive terminal red terminal in the fuse box
    using the plastic yellow gripper.
  4. Use a jumper cable to connect the positive terminal in the fuse box to the positive terminal of the donor battery.
    Note: If the vehicle was locked, the alarm horn will sound when the negative cable is connected.
  5. Use the black jumper cable to connect to the negative terminal of the donor battery to the door frame ground (located on the door arrester.)
  6. Press button 2 on the remote control for approx. 2 seconds to unlock the luggage compartment lid. This will also switch the alarm system off.
  7. Disconnect the negative cable first, then the positive cable.
  8. Push positive terminal C into the fuse box and push on the plastic fuse box cover.


Watch 5-10 YouTube videos on these steps before attempting!

Preferred Method to Deal with Dead Battery

The preferred method to address your dead battery in your Boxster is to charge the battery overnight using the method below.

How to avoid a Dead Battery?

You have to connect the battery to a battery maintainer (not a trickle charger) to charge your battery. Porsche has made this easy via your 12V cigarette lighter located in the passenger footwell.

Use the Best Battery Charger for your Porsche Boxster

Porsche sells a Battery charger for this very purpose.

Where to Connect your Battery Charger

Generally, Automobiles have their 12V Power accessory outlet (cigarette lighter outlet) wired so that the 12V power adaptor outlets will only work when the automobiles are running, or when the key to start the car is inserted and turned to the ACC position.

The 12V power adaptor located in the center console is wired only to be active when the key is in the ignition (except on certain models of 986.) Therefore you need to use the other 12V power accessory adaptor when charging.

The Porsche Boxster Models 987/987.2/981 and 718 have a footwell 12V power accessory adaptor. The footwell 12V power accessory adapter is always on. As a result, when charging your battery during storage make sure to use the footwell 12V power adaptor outlet and not the unit located in the center console.

Boxster 986 European 12V Cigarette Lighter

On the Boxster 986, there are 3 different versions of the cigarette/power adaptor socket. The non-smoker’s package comes with a socket that is 1mm larger in diameter than a normal socket. If your center console is working with your CTEK with no key in the ignition, you are good to go!

UK Boxster 986s are strange. On some, the lighter is hot all the time and on others, it is not. We think it has to do with the year. The owner usually finds out when trying to use a charger that goes through the lighter, because it will not work unless the lighter is hot all the time.


Trickle Chargers

The standard “dumb” trickle chargers provide an unregulated charge to your battery. If left not monitored, trickle chargers can boil a battery’s fluid dry. You need to purchase a smart charger with maintenance mode support.

Maintenance Mode

When you use the Porsche Battery Charger, select the pulse maintaining mode. Pulse maintaining mode charges the battery while storing your vehicle.

What is the Best Battery Charger for your Porsche Boxster

CTEK Multi US 7002 Smart Charger for your Battery

The new CTEK Multi US 7200 is highly recommended, use the CTEK Multi US 3300 at a minimum (no longer being sold.) Also, be sure to purchase the CTEK cigarette plug adaptor and to use the cigarette plug in the passenger side wheel well (not the cigarette plug in the center console.)

The CTEK charger is designed and engineered in Sweden. CTEK is the No. 1 car battery charger for OEM application.

CTEK Chargers

CTEK Multi US 3300 Charger similar to Porsche Charger

The look of this CTEK 3300 Multi US recommended charger should look similar to the Porsche OEM charger.

CTEK is the preferred battery charger for the most prestigious engineering car brands in the world: Porsche, Audi, Lamborghini, Bentley Motors, Scania AB, BMW, Rolls-Royce Motor Cars, Chevrolet (Corvette), Ferrari, Alfa Romeo S.p.A., Maybach-Motorenbau GmbH, Aston Martin, Arctic Cat, Yamaha Motor Company, Maserati, Mercedes, and more.

These chargers are sold as OEM accessories in dealerships such as Audi, BMW, Bentley, Porsche, Ferrari, Jaguar-Land Rover, Lamborghini, Volkswagen, and more worldwide.

CTEK MULTI US 3300 Battery Charger
CTEK MULTI US 3300 Battery Charger

To provide maximum battery charging performance, CTEK is constantly updating its technology. The Original Porsche Charger delivered 4A and now deliver 5A of service. The NEW CTEK Multi US 7200 offers up to 7.0 A of service.

CTEK Chargers on Amazon

I have been a faithful CTEK customer for just over 10 years.

NOTE: If you get the CTEK charger and wish to use your 12V auxiliary power adaptor (cigarette lighter) for charging, make sure to add the Cig Plug adaptor below.

Top 10 Benefits of Using a CTEK Smarter Charger

TOP 10 CTEK Benefits
Click photo for link to the TOP 10 CTEK Benefits

Warnings About Battery Charging

Charging your car battery produces hydrogen gas. Hydrogen gas could cause an explosion, resulting in serious personal injury or death.

  • Always charge your battery in a well-ventilated area.
  • Never charge a frozen battery. It may explode because of gas trapped in the ice. Allow a frozen battery to thaw out first!
  • If you get electrolyte (battery acid) in your eyes, or on your skin, immediately rinse with cold water for several minutes and call a doctor.

About Your Boxster Battery

Boxstertips recommends that you are using an AGM (absorbed glass mat) battery in your car. AGM batteries are maintenance-free, provide good electrical reliability, and are lighter than the flooded lead-acid type. AGM batteries stand up well to low temperatures and have a low self-discharge. The leading advantages are a charge that is up to five times faster than the flooded lead-acid version, and the ability to deep cycle. New CTEK battery chargers have a separate AGM battery support mode.

NOTE: The ultimate battery above an AGM battery, would be the Porsche Lithium-Ion Lightweight Battery starting at just over $5000 USD. Carbon Fibre case included!

Other Articles of Interest

Battery Charger FAQ

How do I use my Porsche battery charger?

Porsche recommends to charge your battery when not using your car for periods longer than 6 weeks. Current model Porsche’s have 12V power adaptor(s) located in the cabin of the car that are hard-wired directly to the battery. Use your Porsche battery charger to use this (hard-wired) 12V power adaptor via the cigarette lighter connector.

Will a trickle charger recharge a dead battery?

Most Trickle charges run at a low power output level. Trickle chargers are not recommended because If a trickle charger is left not monitored, they can boil a battery’s fluid dry. A smart charger such at the Porsche/CTEK Charger 5A can restore a battery to full charge over time.

Is it safe to leave a trickle charger on all the time?

A standard trickle charger should not be left on all the time. If a trickle charger is left not monitored, they can boil a battery’s fluid dry. It is better to use a smart charger or a battery maintainer, therefore avoiding any possibility of incorrectly charging the battery and ensuring the battery is conditioned as well as charged, your batteries last significantly longer.

Can you leave a trickle charger on all winter?

It is not advisable to leave a standard trickle charger on all winter. If a trickle charger is left not monitored, they can boil a battery’s fluid dry. It is better to use a smart charger or a battery maintainer, therefore avoiding any possibility of incorrectly charging the battery and ensuring the battery is conditioned as well as charged, your batteries last significantly longer.

Will a car battery recharge if you let it sit?

No, a car battery will immediately start to dissipate it’s charge level. Car batteries cannot charge themselves. Only the car’s alternator or external charger can restore or maintain the correct charge level of your car battery.

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