I've seen a number of posts this past winter about Battery Tenders or other similar product. I've been an advocate for years (around 10) on this product. My current two Battery Tenders I am using are getting "long in the tooth" (one's 9 and the other 7 years old, used for months at a time over winter) and I noticed it could take as much as 24 hours for the shut off charge (green light) to come on. I also saw another post recently where a member said that his battery tender device burned up his battery. I called the manufacturer and asked the factory technical gurus two questions regarding the cars I use them on (2021 F type R and 2022 Genesis GV70)...
1) is my old BT going to fry either of my car's batteries because of the tender's age? Answer...the only plausible reason a Battery Tender could burn up a battery would be if your car had an older style lead-acid battery and the water/acid level went dry in a cell(s) or got very low. Sealed/no maintenance batteries as are installed in most modern cars recently, it's next to impossible for that to happen.
2) are my two tenders getting worn out, it seems to take a long time to get the car's batteries up to full charge (green light, I call it)? Answer...the age of the BT is the first 4 numbers of the serial number...the first two numbers are the week of manufacture and the second two numbers are the year, e.g. 1714 would be the 17th week of 2014). Both of my BT's are 1.25 amps and the tech told me that used to be satisfactory years ago, but most newer cars have electronic systems and batteries that are way different (more powerful) then the older ones. You really should be using a 4-4.5 amp BT, it will charge those cars batteries a lot more quickly.

So, today I bought two new Battery Tenders, 4.5 amps, from Walmart...around $65 each including tax.
Hope this helps, some one!

 

Both those answers are spot on in my view.

 

Lot's of posts on this subject already.

The best units on the market in my opinion are the Cteks and Victron.


not something you should go with the cheapest option. How much is your AGM battery going to cost to replace??

 

Agree. I've got 2 units which I rate equally highly - CTEK and an OPTIMATE

 

wow...I didn't realize the CTEK tender was that much more superior than the Battery Tender brand. My older 1.25 amp ones I mentioned in my original post came with a 10 year warranty and these new 4.5 amp ones have a 5 year warranty. I'll stay with what I'm used to...hell, I probably wont even own the car in 5 years!

Here is a recently published article comparing the Battery Tender and the CTEK unit...looks like it was published in 2022, so it should be recent.

https://www.cnet.com/roadshow/news/b...ry-maintainer/

 

These are "Paid" placements. What you are reading is advertising. That is why there are links to purchase from the article.

 

I'll have to take your word for it, Zach, regarding the "pay for recommendations" comment. Interestingly, I once again GOOGLEd the "CTEK VS Battery Tender" performance issue and came up with nothing...just a few other write ups that appeared to be like you mentioned.
I'm sure CTEK makes a very good product, but for me, Over the years, I've owned 4 Battery Tenders and have had no issues with any of them. Only one of them crapped out when it was about 5 years old, the factory wanted to see it (probably to check for abuse) and replaced it with a new one and they reacted quickly....so I don't see that as anything negative. So I'll stick with "the horse that brought me", the Battery Tender. It may not be the most expensive or have the gadgets that the CTEK has, but it truly is a very good and reliable battery maintainer.

 

I've had 2 small "Battery Tenders" for twenty years. No problems at all. I would strongly recommend.