Product Comparison: CTEK Multi US 3300 vs CTEK MUS 4.3 (56-864)

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General Specifications
MUS 4.3 (56-864)
About the Product
The CTEK MULTI US 3300 is a versatile battery charger in a compact format that makes it convenient and easy to charge and maintain all household vehicles. The special cold mode means that you can charge during the extreme winter months without problem.
The CTEK MUS 4.3 battery charger is perfect for those with high demands and can solve a broad range of battery-related problems. It offers state of the art technology that was previously only found in CTEK’s professional products and features 8 patented steps to maximize battery life and performance.
Key Specs
Output Current
1100 mA
4300 mA
Output Voltage
Compatible Batteries
Wet, Gel, MF, EFB, AGM
Wet, Gel, MF, Lead-acid, Ca, AGM
Recommended Capacity
90 Ah
160 Ah
Output Cord
12 feet
What customers say about "Key Specs"
CTEK Multi US 3300 Fully Automatic Battery Charger
  • Surely it is an intelligent charger. And which can stay safely connected indefinitely to keeping up a needy and charging battery.
  • The CTEK charged the battery in my 928 from totally dead to fully charged in about 48 hours.
  • Charger worked OK the first few times that I used it but then it stopped detecting any batteries or responding to button pushes.
  • This device would more accurately be called a battery charger/maintainer. It is beautifully constructed out of high quality materials, and works brilliantly to charge and maintain batteries for a variety of transportation modalities (car, motorcycle, etc.).
  • This exact item and model number was recommended on many different car forums that I frequent. If you have a BMW, you know that they are really fussy about everything, but especially the battery. I
CTEK MUS 4.3 (56-864) Fully Automatic 8 Step Battery Charger
  • Works great on BMW's and Chevy's. Supports AGM batteries and regular batteries.
  • Brought two AGM batteries back to life that my old charger could not charge. Worth every penny.
  • We have a bunch of motorcycles in our stable, a few of them use AGM batteries, and we found out the hard way that regular Battery Tenders don't do well with this new battery technology, so we're slowly switching everything over to these new CTek charger/maintainers.
  • A little slow (but that doesn't matter since I'm looking at reconditioning and long term trickle charges).
  • I really don't like the fact that each time you plug the unit into the wall socket there is a noticeable spark it's a little concerning an unnerving. I thought the unit was defective but after reading a few reviews seems to be something common with the unit itself.
Size & Weight
1.5 in.
1.5 in.
6.5 in.
6.5 in.
2.4 in.
2.5 in.
1.1 lbs.
1.4 lbs.
What customers say about "Size & Weight"
CTEK Multi US 3300 Fully Automatic Battery Charger
  • The CTEK 56-158 is small, well-built and virtually identical to the Porsche charger.
  • The unit is small, compact, and pretty tough. You can tell it was engineered for a marine environment and so is very immune to a lot of circumstantial issues that other chargers can't deal with.
  • These small "smart" trickle chargers are perfect for any vehicle that is battery started and does not get operated or driven on a regular basis.
  • This is a nice, small, battery charger that has done a great job of charging and maintaining my car batteries.
  • This is my second purchase of this battery tender. I use them to keep my car batteries charged when the car is parked a long time. They are easy to use, relatively small.
CTEK MUS 4.3 (56-864) Fully Automatic 8 Step Battery Charger
  • It has so many features and the unit is very compact compared to my old charger.
  • Loved the simplicity, the size, weight, packing and the 8 stage.
  • This really does the job. Relatively fast and very light weight.
  • The unit is very compact with ample cord length. I installed permanent battery connector so that I can easily plug it into the car.
  • Charged my motorcycle battery right up, was pleased with the way it works, and it is small and compact.
Start Voltage
2 V
2 V
Charging Steps
1 - Desulphation, 2 - Bulk Charge, 3 - Absorption Mode, 4 - Pulse
1 - Desulphation, 2 - Soft start, 3 - Bulk, 4 - Absorption, 5 - Analyze, 6 - Recond, 7 - Float/Fully charged, 8 - Pulse
Back Current Drain
1 %
0.025 %
Ambient Temperature
- 4°F to +122°F
- 4°F to +122°F
IP Protection
Reverse Polarity Protected
Spark Proof
Maximizes Battery Performance In Vehicles, Reliable In Any Conditions, Extends Battery Life, Trusted Oe Supplier, Low Ripple Advantage, Safe For Vehicle and User
Maximizes Battery Performance In Vehicles, Reliable In Any Conditions, Extends Battery Life, Trusted Oe Supplier, Low Ripple Advantage, Safe For Vehicle and User
What customers say about "Features"
CTEK Multi US 3300 Fully Automatic Battery Charger
  • It has a very nice "recondition" mode to extend battery life.
  • Cables provided are as advertised and the display is almost idiot-proof...also, disconnected the power to see if it defaulted to original settings...but it didn't, thus ensuring a trickle charge will resume even during power outtages.
  • All in all, I'm really happy with this product so far. A nice touch is having the bag that comes with it to store the device and cables.
  • The quick connect cable makes it so much easier than having to unhook and rehook-up each time.
  • The fewer LED indicators on the 56-158 leave something to be desired for information, as compared to the other CTEK's models. It also does not have an LED to indicate "recondition" mode, but the manufacturers information says that it does it automatically.
CTEK MUS 4.3 (56-864) Fully Automatic 8 Step Battery Charger
  • I like the fact that they have in-line fuse’s. Lights are very bright on the unit and the selection mode is responsive when making your selections.
  • The unit feels sturdy and doesn't feel like I'm going to pull any of the cables out of the unit and it does come with a nice bag with a up step-by-step instructions on the back of the bag.
  • The charger has a reconditioning feature that is programmed to attempt to restore a battery that has the plates coated. This is a normal progression of battery life and when the battery is abused.
  • The desulphation program is another great feature I liked that can help restore battery performance. I wish the unit didn't have to keep all the led display lights lit during the float stage of the charging.
  • Clamps could be a little better (stronger with alligator clips).
  • Could have a longer clamp wire (just about for me, but cars with terminals far apart may have an issue).
Warranty / Certifications
Manufacturer Warranty
5 year(s)
5 year(s)
Other Information

Other reviews