CTEK4.3 Test & Charge, 12 Volt Fully Automatic Charger with Unique Battery and Alternator Testing, Ideal for Long Term Storage

This was a second unit in our family... bought by my son for his car. The first unit bought over 2-3 years ago and regularly used is still working fine. The new unit looks like the old except that the output cable now is as robustly constructed as the AC power line. The old output cable was just a 2-wire cord (unprotected). Otherwise same as before.... works great.... simple operation... and very effective in keeping car batteries from being from being flat due to prolonged lack of use.

I have a 2009 BMW 335 that I drive infrequently. I was getting the yellow low battery and inspection pictograms regularly. The battery is less than 1 year old. Before using this charger I confirmed that it isn't an AGM battery. I bought the extension cables so I could close the hood while charging.The CTEK does work, but it takes a long time to go beyond step 4 to step 7 (green light, fully charged). Once fully charged the pictograms stopped coming up. The 1st charge attempt with the recondition step included took more than 24 hours to reach full charge., but the battery was low again after 1 week of not driving, the time went blank. Reaching the fully charged state again in the 2nd charging session without reconditioning took about 3 days! I am leaving it connected for an extra day or so in the hope that the battery will remain fully charged longer.

This charger keeps one’s battery at its full and best charge state for the many days when car is garaged.It will let you know if there is an issue with your battery so steps can be taken before battery failure when away from home. Provides peace of mind. Phil – 01-09-2025

Cord could be longer. Bought extension.

Easy to use. Keeps battery charged. Just a bit pricey for what it is.

The MUS 4.3 Test & Charge is my second CTEK Product (the first being the Lithium US for my motorcycle). Please be advised that I may be slightly biased (not affiliated/sponsored by anyone).I purchased this unit specifically for keeping charge on stored vehicles and reconditioning batteries in daily driving cars. Per the user manual, CTEK recommends RECOND once a year or whenever battery is depleted completely. If you’re just buying this unit for the first time, it might be a good idea to RECOND too.It took about 9.5 hours (15:30-01:00 next day) to complete all 7 cycles, including RECOND, on my BMW F13 650i. Even though this car mostly sit in my garage for the past half a year or so, it still kept a lot of juice. Its BMW OEM battery is either 90 or 105 Ah, that would take a longgggggg time to charge if it were completely dead.Yes, CTEK is much more expensive than competitors’ products, but it has automatic sequence to test, charge, and maintain your batteries. Other products out there will certainly get the job done as well, though I’m not sure if they’ll do it as well as this unit. There is a nice feature splitting the charge sequence into a faster bulk cycle (<80%) and absorption (80-100%). Not to mention that it will perform tests on the battery and alternator so you won’t waste electricity to charge if it will just die again soon.Generally speaking, $100 for this product is amongst the best investment for your precious weekend cars. If you can afford to have fun, you should definitely keep a battery trickle charger on hand, especially if you live in a colder climate. You wouldn’t want a dead battery to ruin a nice day out, and you definitely don’t want inferior chargers to damage your batteries.

Easy tips (that are not in the manual or on any video)1) TESTING the battery: don't plug in the CTEK MUS 4.3 (into a power outlet) just hook it up to the battery and flip the mode to the appropriate one you wish to test.2) Charging the battery: Plug into the wall, clip on the battery, select an appropriate mode.I had a DEAD battery. I refilled it with a proper mixture of Epson salt + distilled water. I put on an older charger that did steady 2 amps for 24 hours (caps off). Once it was "boiling" I removed the older charger and place the CTEK on the battery. Set it for reconditioning, did this twice. The battery holds a perfect charge.Note: Epson Salts + distilled water will work. I didn't need to remove the old battery acid. The batter was 22 months old, it was just sitting for almost a year.250g Epson salt + 16 oz of Distilled water.Magnesium sulfate and lead sulfate undergo a single replacement reaction. Magnesium metal is more reactive than lead, so it is capable of replacing it in the plates. Take note; Magnesium sulfate is highly soluble in water. With this, lead metal is gradually restored and removed around the plates

Would buy again