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Battery Chargers > Battery Charger > 4-Step Charger > 12 Volts > CTEK Power Inc

CTEK MULTI US 3300 12-Volt Universal Battery Charger w/ Pulse Maintenance

CTEK Power Inc Battery Chargers

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Code:   CTEK56158



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Shipping Weight: 2 pounds


CTEK Power Inc Battery Chargers - CTEK56158

This powerful, all-weather, four-step charger uses a patented, pulse-maintenance system to charge and maintain all household 12V batteries - cars, campers, mowers, trucks and boats. A practical battery charger fits most applications.


  • Reliable, maintenance-free, 4-step system constantly monitors and maintains 12V battery charge
    • Won't overcharge or undercharge like common trickle chargers
    • Switches automatically to pulse-maintenance phase when full charge has been reached
    • Reduces risk of overheating, sulfation and premature battery failure
  • Easy-to-use, quick-disconnect system
    • Includes 2 battery-cable attachment systems w/ Comfort Connect end plugs - charger plugs right in
      • Eyelet-terminal cable permanently attaches to battery terminals
      • Clamp-terminal cable temporarily clamps to battery terminals
  • Safe, versatile design
    • Approved for indoor and outdoor use
    • Prevents reverse-polarity mistakes
    • Offers (3) 12V current modes
      • Motorcycle icon: lower current for smaller 12V batteries
      • Car icon: higher current for larger 12V automobile and marine batteries
      • Snowflake/AGM icon: special winter mode designed for charging and maintenance in cold weather; also recommended by many AGM battery manufacturers like Optima, Maxima and Odyssey
  • Convenient accessories (sold separately) provide additional security and convenience
    • Know your battery's charge level at a glance w/ optional LED-indicator battery cable
    • Reduce the hassle of charging multiple vehicles w/ additional battery-hookup cables


  • Application: most starter and deep-cycle, 12V, lead-acid batteries - including wet, MF, AGM and most gel batteries
    • Charges batteries w/ capacities from 1.2 Ah - 75 Ah
    • Maintains batteries w/ capacities up to 120 Ah
  • Charge cycle: 4-step, fully automatic charger w/ pulse maintenance
  • Dimensions: 6.5" long x 2-3/8" wide x 1.5" tall
  • Includes:
    • 12V Battery charger (w/ 5' battery-connection cable and 6' power cord attached)
    • 1 Set of 16" battery cables w/ battery-terminal clips
    • 1 Set of 16" battery cables w/ M6 (6.4-mm) eyelet terminals
    • Owner's manual
    • Protective case
  • 5-Year warranty
CTEK MULTI US 3300 bulk charging time chart

This CTEK charger comes w/ two battery cables: one w/ clamp terminals and one w/ eyelet terminals. The 16" long eyelet-terminal cable can be left attached to the battery, and the clamp-terminal cable is great for temporary connections.

CTEK MULTI US 3300 Charger w/ both clamp and eyelet cables

Whenever you want to charge the battery, just plug CTEK's patented Comfort Connect attachment terminal into the receiving end on either of the provided battery cables.

Close-up of CTEK's Comfort Connect plugs

CTEK MULTI US 3300 Charging Process

Safe, four-step process uses switch-mode, pulse-maintenance technology.

  1. Desulfation stage is the initial charging phase. This stage uses electronic pulses to desulfate batteries by converting lead sulfate crystals back to usable sulfuric acid.
  2. Bulk stage is the main charging phase. This stage accounts for 80 percent of the charging process and uses a constant charge level.
  3. Absorption stage completes the charge (to virtually 100 percent) using diminishing current to prevent battery damage.
  4. Pulse-maintenance stage begins 18 hours after the battery is fully charged. In this stage the charger maintains the battery at the optimum charge level of 95 to 100 percent by recognizing any drop in voltage and sending a corresponding pulse of current to keep the battery properly charged. Pulse maintenance can be continued for months at a time.
CTEK MULTI US 3300 charging process chart

A goof-proof design distinguishes CTEK's new-generation chargers from the competition - you don't have to be a mechanical guru to keep your battery working at top efficiency. CTEK's patented charging system monitors your battery, providing exactly the charge it needs during each unique charging stage!

Protects the User

Your personal safety is paramount, and CTEK's spark-free, short-circuit-proof design incorporates a feature that prevents reverse polarity, keeping you safe. You simply cannot make a polarity mistake: The charger will not operate if it is attached incorrectly. In addition, the red alarm light on the charger alerts you if there is a reverse-polarity problem.

Protects the Battery

CTEK's patented, switch-mode, pulse-maintenance charging system is scientifically engineered to safely charge your battery by employing the most up-to-date technology. Using carefully monitored, low-grid voltage, CTEK's patented process differs from competitors' chargers in its ability to provide the precise final voltage that your battery needs to maintain optimum charge level. This sophisticated, interactive device will never overcharge or undercharge your battery. You may leave it attached to the battery for months, making it perfect for seasonal vehicle storage.

Won't cause overcharging or overheating. These together can cause gassing and excessive acid concentration that shortens the life of the battery by corroding the lead plates. When overcharged, the battery cells become dried out. Electrolytes "boil dry," generating excessive heat that can cause a fire.

Won't cause undercharging or sulfation. Undercharging can be just as damaging to your battery as overcharging because chronic undercharging leads to sulfation. Sulfation occurs when the lead and lead dioxide of the battery's plates react w/ sulfuric battery acid to produce lead sulfate. This in turn is converted back to lead, lead oxide and sulfuric acid. A small, unavoidable amount of sulfation and gassing naturally takes place as a result of the chemical processes occurring in lead-acid batteries. However, extensive undercharging causes extra lead sulfate to accumulate on the lead plates of the battery. Because the crystalline form of the sulfate cannot hold an electrical charge, excessive sulfation greatly diminishes the charging ability of the battery, eventually rendering it unusable.

Provides desulfation w/ a patented process. Desulfation is the reversal of sulfation damage. The CTEK charger's unique process not only prevents the undercharging that produces excess sulfation, it also includes a desulfating step that can often "revive" a lightly sulfated battery. It accomplishes this w/ carefully monitored electronic pulses of energy that help to break down the lead sulfate crystals, allowing the battery to accept charge once again.

Ensures consistent charging w/ low ripple-wave percentage rate. Ripple-wave percentage is the quantity of disturbances exhibited in current and voltage. Even minor variations in household current can cause undercharging or overcharging, but CTEK's low-ripple design regulates the incoming current before passing it on to your battery. This process can cause the charger to be a little slower than linear chargers but results in a healthier, more productive, longer-lasting battery.

Protects the Vehicle and Its Electronics

The charger is also safe for your vehicle. Its sophisticated circuitry is designed to be compatible w/ today's sensitive electronics and audio equipment. You can confidently charge your battery while it is still in the vehicle: no more hefting heavy batteries or dealing w/ tiresome system resetting! CTEK's low ripple rate eliminates the danger of damaging electronic devices connected to the battery, and it prolongs the battery's service life.

CTEK MULTI US 3300 indicator chart

Indicator lights on the face of the charger light up to show the current charging stage.

Additional Specs:

  • Model: 56-158 (MULTI US 3300)
  • Input voltage: 100 VAC - 120 VAC, 50 Hz - 60 Hz
    • Output power is reduced at lower input voltage; a perfect charge will still be achieved
  • Current: 1.1A rms (at full charging current)
  • Charging current: 0.8A - 3.3A max
  • Back current drain: 1.3 mAh per month
  • Charging voltage: 14.4V - 14.7V
    • Nominal charging voltage: 12V
  • Ripple wave: less than 2 percent variance (max 50 mV rms, max 0.13A)
  • Battery cable fuse: 15A
  • Ambient temperature: -4 degrees F to +122 degrees F
    • Automatic reduction of power at increased ambient temperature
  • Cooling: natural convection
    • Do not cover the charger

56-158 CTEK MULTI US 3300 12V 4-Step, Pulse-Maintenance, Lead-Acid Battery Charger

Video of CTEK MULTI US 3300 12-Volt Universal Battery Charger w/ Pulse Maintenance

Videos are provided as a guide only. Refer to manufacturer
installation instructions and specs for complete information.

Video Vendor Information Ctek
CTEK Battery Charger Vendor Information
Video install ctek universal battery charger 2013 mercedes benz sprinter ctek56158
CTEK Multi US 3300 12-Volt Universal Battery Charger Review

Video Transcript for CTEK Battery Charger Vendor Information

CTEK was founded in Sweden. Basically our parent company is a prototyping company. Prototypes everything from plastics to electronic equipment right down to batteries but we actually consider ourselves a battery company with out batteries. We know everything about them. How to make them last longer and perform better. We just deal with the charging and maintenance end of it. 00:18

We have a patented mode of charging for one thing that we go through. Ultimately what this is going to do is bring our battery up to charge and then shut off completely versus your traditional trickle mode or linear charge like others might do on the market. If you could actually see current and voltage what you would see with those traditional charges you are putting in the same current and voltage high amperage level. We actually consider those toasters a lot of times because they generate more heat than charge and ultimately can toast the battery if not used properly or left on too long. 00:45

We have a patented mode of charging for one thing that we go through. Ultimately what this is going to do is bring our battery up to charge and then shut off completely versus your traditional trickle mode or linear charge like others might do on the market. If you could actually see current and voltage what you would see with those traditional charges you are putting in the same current and voltage high amperage level. We actually consider those toasters a lot of times because they generate more heat than charge and ultimately can toast the battery if not used properly or left on too long. 00:45

We realize that nobody cares about their battery. It is an evil that nobody wants to see and unfortunately nobody cares about it until it is too late and there is a problem where your vehicle does not start or your batteries are discharged to the point where you need to replace them. With our add on series, the comfort indicator, we have simply made your battery visible now. It is a one time installation. You bolt it directly to the battery with the flashing LED lights in there at all times visible you know where your battery stage of charge is at and if you need to charge it. Everything about our charger is we try to make it really safe, easy to use, and very functional. That is part of the quick connect and comfort indicator series that we have launched. Basically the concept behind it is you can have your one time installation on the battery especially with the comfort indicator series with the LED lights in it, now your battery is actually visible. You know at all times when you need to charge your battery and then it is pretty easy to use basically and you can balance your charger from vehicle to vehicle as you need to charge. 02:07

We like to think we have the best charger on the market. We try to stay ahead of the curve with the technology that we are putting into the battery chargers. CTEKs all are back by five year no questions asked warranty. Every household needs one of these chargers. It is a very robust design and it absolutely works on everything. From your lawn tractor, your boat, your RV, your motorcycle, your sports car. It is a very indispensable product to have.

Customer Reviews

CTEK MULTI US 3300 12-Volt Universal Battery Charger w/ Pulse Maintenance - CTEK56158

Average Customer Rating:  ratingratingratingratingrating4.8 out of 5 stars   (13 Customer Reviews)

This powerful, all-weather, four-step charger uses a patented, pulse-maintenance system to charge and maintain all household 12V batteries - cars, campers, mowers, trucks and boats. A practical battery charger fits most applications.

- CTEK56158

ratingratingratingratingrating by: Bob B. - Employee11/14/2013

Got a booming radio that tends to kill the battery after a day of hanging out at the gravel bar. This charger I installed under the hood and ran the plug to the front bumper. So I have 2 options. 1. If there is power nearby just plug it in and no worries. 2. At the end of the day when back at the house just plug in overnight so battery is fully charged the next day without needing to leave the truck running to charge back up. 107360

- CTEK56158

ratingratingratingratingrating by: Kevin12/26/2012

The CTEK 3300 is being used to keep my hot rod battery charged because it's not a daily driver. It took about one day and then the amber light turned green and has stayed that way for a month now. All I do is unplug the unit from the car and it starts right up. It sure is nice to be able to leave this one hooked up to the car in place of my older one that I would only use for a few hours at a time. So far I'm very happy with it and I would buy another one if I had two batteries to keep charged. 61891

- CTEK56158

ratingratingratingratingrating by: Joel B.06/30/2011

Great charger's that are made by CTEK E-Trailer's service is great and fast. 18284

- CTEK56158

ratingratingratingratingrating by: Robert LaBonte10/08/2013

Very well made. Seems to have every needed option. 103020

- CTEK56158

ratingratingratingratingrating by: Triple D Ranch07/22/2013

thank's work's good 90944

- CTEK56864

ratingratingratingratingrating by: Adam R. - Employee01/20/2014

Review from a similar CTEK Power Inc 12-Volt Universal Battery Charger

I have another trickle charger that I've used for years on my older Harley, but it is a single-mode charger. I decided to get a second one so I do not have to constantly move the one from the bike to the lawn mower to the car, etc and chose this one based on excellent reports from my co-workers who also use this C-TEK unit. Having had this in use for about 3 weeks now I can report that it works well, offers several modes, including the winter storage mode I am using now, and came with very detailed instructions and plenty of adapters for various applications. I'd buy this again. 114205

- CTEK56353

ratingratingratingratingrating by: Todd06/07/2011

Review from a similar CTEK Power Inc 12-Volt Universal Battery Charger

This is my second purchase for etrailer. The service has been excellent each time, and the quality of the products is also excellent. The CTEK battery charger is easy to use. I have used it on Optima batteries, which don't charge as well on conventional chargers. It works great. Just hook it up, and it stops when it is finished. 16321

- CTEK56864

ratingratingratingratingrating by: David04/08/2013

Review from a similar CTEK Power Inc 12-Volt Universal Battery Charger

The reconditioning mode on the 4.3 did in fact recondition my car battery when simply charging it with a CTEK 3.3 didn't. I conclude this based on the better retention of charge after the 4.3 than after the 3.3. As always, etrailer's service was prompt and courteous when I ordered a second 4.3 DS 74922

- CTEK56864

ratingratingratingratingrating by: Barney B05/24/2014

Review from a similar CTEK Power Inc 12-Volt Universal Battery Charger

Very high quality, compact, easy to use charger with many features. It is perfect for maintaining a charge on batteries that only get utilized periodically but can be used to charge as well. Would definitely recommend both the charger and 132255

- CTEK56864

ratingratingratingratingrating by: Dan S.12/20/2013

Review from a similar CTEK Power Inc 12-Volt Universal Battery Charger

This CTEK charger got my large automotive battery up to full capacity in no time, and is maintaining it perfect through cold winter storage. As usual, prompt & well packaged delivery from etrailer! 110746

- CTEK56864

ratingratingratingratingrating by: AD03/25/2013

Review from a similar CTEK Power Inc 12-Volt Universal Battery Charger

I have ordered products from etrailer for years and have never been disappointed in the products , price or promptness of delivery. 72365

- CTEK56864

ratingratingratingratingrating by: Ted C.11/28/2012

Review from a similar CTEK Power Inc 12-Volt Universal Battery Charger

Have ordered from etrailer in the past, fast shipping and battery charger seems to operate fine! 60127

- CTEK56864

ratingratingratingratingrating by: R Hochnadel02/20/2014

Review from a similar CTEK Power Inc 12-Volt Universal Battery Charger

Exactly what I needed to maintain several different size batteries at the same time. 117061


Ask the Experts about this CTEK Power Inc Battery Chargers
Expert Answers about CTEK MULTI US 3300 12-Volt Universal Battery Charger w/ Pulse Maintenance - CTEK56158Do you have a question about this Battery Chargers?

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  • Can the CTEK Battery Chargers Resurrect Nearly Dead Trailer Break Away Batteries
  • The CTEK US 3300 12-Volt Battery Charger, # CTEK56158, may be able to resurrect your batteries but if they were dead long enough, they would probably be too far gone to bring back to working order. The best bet for this scenario would be the CTEK MULTI US 7002 12-Volt Universal Battery Charger, # CTEK56353, because it has a special reconditioning mode that restores the power capacity of stratified batteries. The 7002 also has an 8-step charging process.
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  • Can the CTEK MULTI US 3300 12-Volt Universal Battery Charger be Used on a 12 Volt 2 Battery System
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  • Using 7-Way Accessory Circuit to Maintain Trailer Mounted Battery
  • That is a great question. The 12-volt accessory feed from the 7-way CAN be used to maintain your trailer-mounted battery during travel, but it will NOT recharge a battery from a depleted state. To charge a depleted battery, a charger like the # CTEK56158 CTEK Universal Battery Charger can be used. The 10 or 12 gauge wire used in the accessory circuit will prevent enough current from going through to worry about overtaxing or damaging the alternator. To prevent the trailer mounted battery...
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  • How To Charge Trailer Battery From a Chevrolet Silverado With a 7-Way Connector
  • To keep the trailer battery charged you will need to run a 10 gauge power wire like the, part # 10-1-1, from the 12 volt power pin (# 4 terminal at 11:00 position) on your trailers 7-way connector, to the positive terminal on the trailer battery. Now when the trailer is connected and you are towing, the tow vehicle will provide a maintenance charge to the trailer battery. It will not charge the battery from a discharged state. You will want to test the # 4 terminal at the 1:00 position...
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  • Will CTEK Battery Charger Charge Battery Without Damaging It?
  • If the car battery is merely discharged but otherwise in good repair, using a CTEK charger will not damage it. CTEK chargers will not over charge a battery, once full charge is reached, the charger switches to pulse maintenance, which maintains the charge rather than applying full power to the battery. A charger like the CTEK Multi US 3300, part # CTEK56158 would be best suited for a car battery. The charger is suitable for deep-cycle batteries. This charger features three modes, one...
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  • CTEK Battery Charger Does Not Stay in Desulfation Stage for More than a Few Seconds
  • There is no set time for each charging phase for CTEK battery charger # CTEK56353. If the battery is at or above the terminal voltage preset level then it will go on to stage 2. This would mean that the battery does not necessarily have sufficient lead sulfate crystals that need to be converted back to sulfuric acid. Also, on batteries that are completely dead or have excessive sulfation, the charger will not be able to resurrect it. Check to make sure that the connection points on the...
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  • Differences Between CTEK Battery Chargers # CTEK56864 and # CTEK56158
  • Both products are smart chargers, meaning that they adjust their charging current and voltage continuously depending on the condition of the battery being charged, rather than pump the same current continuously. Both automatically switch to pulse maintenance mode once a full charge is reached. I have included a manufacturer video that might be of interest and also one demonstrating one type of installation in a vehicle of part # CTEK56158. The CTEK Multi Universal Charger, part #...
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Info for this part was:

Test Fit:
Joe V

Expert Research:
Michael L

Video by:
Andrew K

Expert Research:
Patrick B

Expert Research:
Michael H

Expert Research:
Jameson C

Expert Research:
Rachael H

Video Edited:
Chad S

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