Well, the Black and Decker/Vector 2A smart maintainer I bought about 2 years ago appears to have taken a dump. It charges my battery up to 14.5VDC at 2A even though the battery is sufficiently charged. I noticed a lot of electrolyte boiling out of the positive terminal and was curious as to why it is doing it. Luckily this happened on my other car (not the Stang) and on a 3 year old battery.

I'm looking to buy a new smart battery maintainer and need something that is 110% reliable as a set and forget setup that can withstand -20F winters and +100F summers with 100% humidity.

What does the Stang community recommend? I noticed that Deltran has a 0.75A Battery Tender Jr for $30, a waterproof 0.8A Battery Tender for $40, and a 1.25A Battery Tender Plus for $50

Thanks in advance!

 

I stand behind this one from harbor freight. Cant beat it for the price. Left it on my 08 GT last winter for 5 months, and she started right up. Why waste a bunch of money on the expensive ones, all it needs to do is maintain the charge (not to rub it in, but it looks like it works better then your B&D which was probably not cheap)

Oh yea, I live in Michigan where the weather is crap most of the time -10 to 100 degrees and mega humid and it still works like a champ.

 

Are you talking about the $6 Harbor Freight float/maintainer? I have that one and it seemed rather puny at first. Did you charge up the battery first before using it? It was never designed to be a charger, just a maintainer.

The B&D was $18. I'm willing to spend a little more for something that is 110% reliable since it will be used on the Mustang.

 

there is only one answer. Battery tender plus. They have been building em for 30 years and I have been using em for almost that long. The cheap one from harbor freight will never withstand the elements you describe.

 

What about the Battery Tender Jr or Waterproof units? Does the Tender Plus use a lot of mechanical parts?

 

is one less expensive to run than the other? Ele bill wise

 

The Battery Tenders come in 3 flavors for our application (maintainer):
0.75A (Jr)
0.80A (waterproof)
1.25A (Plus)

I liked the 2A because it would actually provide charging plus float maintenance, but I suppose even .0.75A is enough to overcome parasitic draw (about a max of .25A) and supply some charging capacity to the battery.

I am intrigued by the Waterproof unit because it is supposed to be fully encapsulated. Supposedly you could charge the battery with the Tender submerged in water and it is resistant to vibration and shock. The Tender Plus seems the most powerful but is also the largest/bulkiest and I assume it has more mechanical parts with large/fat transformer coils.

 

I think you'll be happy with any of the Battery Tender line. The jr. will charge and maintain and should be plenty sufficient to keep a charged battery maintained.

 

I've used my Battery Tender Jr on a variety of both conventional and AGM/dry cell batteries over the last 3-4 years and I've been very happy with it. I have found that it will charge a battery over time, but it obviously takes longer than a charger/maintainer with higher output. It will bring the little 7 lb AGM battery in my Miata up to a full charge (after being run completely down....interior lights left on) in less than 24 hours. Bigger batteries take a little longer. Paid $30 for it IIRC and it has been worth every penny. I might even get a second one this winter since I'll likely store 2 or 3 of my cars over the winter, although in the past I've just switched it from one car to another every week or two during the winter and that method has worked to keep them all topped up.

 

I use the Battery Tender Plus; I bought it at Pep Boys out here in Cali. I works great it comes with a detachable cord that makes hook up easy when the car is in storage. The Tender has taken a dead battery and overnight fully charged it for confident rides. I highly recommend this unit, it's a little more expensive than the others but at always you get what you pay for.

Jed

 

I examined the Black and Decker and couldn't find the source of the problem. I did see signs of moisture/condensation buildup inside the plastic casing. I'm pretty sure I want a fully encapsulated/waterproof charger now.

 

I have used the Battery tender Jr. for my boat and my Mustang with very good results.

 

I'm curious about the Tender Jr and Tender Plus. They don't look like sealed units, so how well do they fare against moisture and extreme temperature conditions?

 

The Tender Jr I have is just a wall-wart with all the circuitry built into the part that plugs into the outlet. Looks pretty well sealed up to me, assuming the outlet you're plugging into isn't in a place with high moisture. I use mine inside, but my unattached garage sees temperature swings from below 0 to over 90 degrees every year, and has occasional problems with moisture/condensation inside. Never had a problem with my Tender Jr in the 3-4+ years I've had it.

 

I did some quick comparisons between the Jr and Waterproof models and found that the Jr. is $10 cheaper and has a 5 year warranty compared to the 3 year on the Waterproof.

Since it will be in my dry garage I pick the Jr.

 

The Tender Waterproof arrived and it is a very beefy unit. It's about as heavy as a brick even though it's the size of a small discman, I guess it is from the encapsulation. From my experience, warranties are almost meaningless. I learned that the hard way with Goodyear tires and many other expensive items.

 

It looks like the Battery Tender crapped out. I left it on for 6 hours and it is still charging (amber LED) at 14+ VDC @ 0.8A (max current). I can hear a boiling sound from the battery. So much for a smart charger...

 

brand new? I have been using em for over 20 years with never an issue with em in 365 days a year. Think about that..

 

Hopefully, that warranty will actually be of use to you this time...

 

Sorry for the late update. I re-read the instructions and couldn't find any useful data. I went online and read some PDF files and discovered that the Tender needs to charge the battery until it reaches 14.4-14.5 VDC (during the absorption charge phase) before it goes into maintenance/float modes. This caused my battery to make gurgling noises since it had to maintain 14+ VDC for quite some time, but I haven't seen any signs of boiling over or acid seepage through the terminals. It switched to the "green" mode by itself, so I think all is well.

If I had to do this again I'd probably use a dumb charger at 10A to boost the battery charge before using the lower capacity Battery Tender.