I have been using my CTEK 3300 daily just after a week after I purchased my 2010 Jag Xk in 2014. I also have a spare 3300 I use at times for my other car ( Lexus LS430) It works fine other than an occasional glitch with the power button unable to change the modes properly. After speaking with CTEK customer service today, I was informed that the power button becoming problematic is common. I'm still under warranty and CTEK is willing to upgrade me to a CTEK MUS 4.3 (reconditioned).. no cost to me other than shipping it back. Is it worth while to upgrade to the MUS 4.3 or the latest MXS 5.0? I'm willing to just buy a brand new one on Amazon for a few dollars more than the 3300 if it is worthwhile. Not sure about the MXS 5.0 as it is out a shorter period of time. What maintainer do you guys have and do you think one is that much better than another? Thanks all for the feedback.

 

I have a CTEK MUS 4.3 and recommend it over the 3300 because it is a newer design with additional functions. Because your 3300 is defective and under warranty, it's definitely worth upgrading to the MUS 4.3 for a nominal shipping cost.

I can't address the differences, if any, in functionality between the MUS 4.3 and the MXS 5.0. Because they're similar in appearance and both use 8-step charging modes and work with AGM batteries, I don't know if the price difference is just marketing hype or is for a real difference in functionality and performance. I suggest that you read the user reviews on Amazon for both models. Here's the Amazon product descriptions:



Let us know what you decide to do.

 

Thanks Stuart S... The product reviews don't help much and they try to hype the sales. Getting an exchange for my faulty 3300 won't be my decision maker either as I always get my preference regardless of best prices. I'm leaning toward the 4.3 because of the many positive reviews now and in the past when it first was introduced. I don't need 2 of them and will keep my 2 3300s as back ups.. So.....that's the answer. Purchase the MUS 4.3 and after using it. give my review. Not looking to exchange my 3300 for a remanufactured CTEK.. I always want NEW NEW.. period.

 

 

I have both the 4.3 and the 4.3 Charge and Test. I like them both but the Charge and test has a thick wire to the convienience plug (so an extension would be needed if you shut wire through trunk).

 

Update: I have my new battery installed in my 2010 XK with my CTEK 3300 attached directly to the battery via eyelets to positive and negative to a ground in trunk. I have a comfort cord coming out of the trunk between the rubber seals. I can see the amber going to green and back to amber. It stays on each mode maybe 15 seconds or so. Back and forth. I changed the charger itself with another CTEK 3300 and it does the same thing. Calling tech support doesn't diagnose but the tech tells me the charger is doing what is was intended to do. Again, he is willing to exchange my 3300 for a remanufactured 4.3 MUS, but my concern is why are both of my chargers doing the same thing when they never did it for all the years of my car ownership? Is it something with my car? The battery that I removed is is great shape so I know the charger has not damaged the battery. Not sure of my next step other than waiting for the trunk lights to go out after awhile and see what the voltage is at the battery when the modes change colors. To be continued.

 

Hook up the charger , close the boot and lock the car. Walk away for a few hours and come back to take a look. I assume the charger is outside the car. It should be green . Don't bring the key back , leave it inside away from the car.

 

Here are my results at the battery with the CTEK 3300 hooked up after leaving hatch open until lights went off. CTEK will show green and stay on for approximately 20 seconds. At the battery when green, and once Voltage drops to 12.79 CTEK then goes amber and voltage shoots to 14.23 Volts within a total of 7 seconds and then the CTEK Turns green again. I assume that CTEK 3300 wants the voltage to stay above 12.80 before kicking in the charge mode (amber). (I wonder if the CTEK MUS 4.3 will behave differently)

PS. For all I know, my CTEK 3300 might very well had been behaving this way from the day I purchased it 4 years ago! I never actually stood over it and watched it switch modes from amber to green. Sometimes we over analyze but can never be sure what was in the past. One thing is for sure. My original battery with the 3300 is still good as new! Go figure.

 

Boca I have the 4.3 MUS on my car. It is an 8 step charger with the 8th step being a pulsed long term charger. I believe it kicks in after maybe 3 weeks . Take a look at the Ctek web site and it gives a good description on how it works and what it does. Also there are some youtube demos that also shows how it works. As you saw I have an external connection and the unit is mounted to my lift and I just plug it in under the rear of the car. I last took my car out 5 or 6 days ago and plugged it in after the drive. It goes through all of it's cycles and stops at step 7. This is green and the float charge stage. The voltage it puts out to maintain the battery is 13.7 V and sits at this voltage until it meets the 3 or 4 week stage and the voltage changes. I have not read the charging cycle of the 3300 so I can't say if it cycles from green to amber and at what voltage.