Amazon.com: Customer reviews: Battery Tender 12 Volt Junior Automatic Battery Charger

Top positive review

Includes harness not shown in pictures. Don't buy an extra one unless you need to.

December 23, 2016

The item description and images fail to indicate that this item DOES include the ring terminal harness for permanent attachment to your battery. No need to purchase the item linked here: Battery Tender 081-0069-6 Ring Terminal Harness with Black Fused 2-Pin Quick Disconnect Plug

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mustryde

Bummed Out

November 4, 2017

I ordered 2 of the 021-0123 Battery Tender Juniors. They arrived on time, I unpacked one of the 2, hooked leads up to the car battery, plugged in the charger and watched the light as I made the final connection. Everything went as the manual said it would. I was waxing the car as the charger was doing it's thing and after about 15 minutes the charger started "clicking" and died. I unplugged it and waited a few minutes, plugged it back in, and nothing.
I unpacked the 2nd 021-0123 Battery Tender Junior, intended for my motorcycle, plugged it in and it lasted maybe 15 seconds and did the same "clicking" thing and died. The replacement process went smooth but I have not received the new ones yet.

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Peter

Works great with cars

May 21, 2018

Size: 12V @ 750mAVerified Purchase

Works great with cars, riding mowers, and just about any farm machinery with a battery. A great feature is if you touch both connectors there is no chance of a spark. Charges battery and a lot of indicators. Only minor issue is the green and red lights provide the status: blinking, solid, on or off and it's not clear what it means. The legend is written on the wall unit and is very small and hard to read.

If you’re trickle charging a battery to prevent it from dying. For example your sports car in the winter sitting in the garage or other equipment then be sure to keep it plugged in until you use it again. Don’t unplug when the battery is charged and plug it in a few days later. The unit knows when it’s charged and won’t charge a full battery. So keep it plugged in all winter.

If this was helpful please click Helpful below. Thanks!

165 people found this helpful

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11 comment

RedSled

Highly recommended!

November 1, 2016

Size: 12V @ 750mAVerified Purchase

Bought a pair of the Tender Jr. in 2012. I'm sure they have paid for themselves by maximizing the life of my expensive lead-acid batteries. There are plenty of reviews here proving that this is a quality product that has been around a long time. I wish to add that the company that makes Battery Tender products, Deltran, stands by their products. One of my "Juniors" recently stopped working after four years of continuous service. I emailed the company and received a prompt reply. I returned the unit and received a brand new replacement covered under their 5-year warranty. You can't go wrong with this product or company.

Edit: For those considering this product... It is not a battery charger. It is for maintaining fully charged batteries. There are some negative reviews from folks that did not realize what they were buying.

90 people found this helpful

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33 comments

GoldwingDocs

If you own anything with a lead-acid battery, you need one of these. Best charger available!

December 7, 2014

Size: 12V @ 750mAVerified Purchase

This is the ubiquitous Battery Tender Jr., manufactured by Deltran. There are quite a few float charger type products out there that bill themselves as "battery tenders" but the actual product name of this is "Battery Tender Jr." - they have other Battery Tender products, including one with higher charging output, and one with more outputs for charging multiple batteries.

But let's first get back to basics: what is a float charger, and why is it needed?

Lead-acid batteries, of the type used in cars and motorcycles, lose a part of their charge over time just sitting when they aren't even connected to something. When left in a bike that has a clock or radio memory circuit in it that constantly draws power even when the bike is off, that loss of charge is even faster.

Lead-acid batteries "like" to remain at full charge at all times. A battery that is kept at full charge will have a much longer service life than a battery that is left sitting with less than a full charge.

I used to go through a lot of batteries - my motorcycle batteries would last between one and two years before they needed replacement. With multiple motorcycles (not to mention other battery powered things like a generator, snow blower, etc.) this gets expensive!

I figured I would put a trickle (float) charger on my main GL1100 battery to help keep it fully charged. I bought a cheap trickle charger from Harbor Freight, for under $10. I hooked it up to the battery and left it sitting overnight. The next day, to my utter surprise, the battery was dead! The cheap trickle charger, with no intelligence in it and no way of turning off when the battery was charged, overcharged the battery, destroying it! I could charge it fully, but its plates were sulfated, and it would no longer produce enough current to start the bike. This was an expensive lesson - and taught me about the false economy of Harbor Freight float chargers!

So it was with a bit of trepidation that I tried the Battery Tender Jr. - I didn't really want to throw another $100 down the drain for another new battery. The difference with the Battery Tender products is that they are intelligent: they have computers inside that analyze the state of charge of the battery to which they are connected, and alter their output to adjust: Initialization, Bulk Charge Mode, Absorption Mode, Float Mode).

The result: I'm still using that battery five years later, and it still works like it is brand new. I was so impressed that I bought more: I now own five Battery Tender Jr.'s, and they are connected to all of my bikes and devices, 24/7. Every time I park my bike, I plug it in. I have not had a single battery go bad in the five years since I have started using Battery Tenders - and every battery still performs like it is brand new.

The Battery Tender Jr. comes with a 12 foot cord and a plug. This plug then attaches to one of two included connectors: a set of alligator clips, for temporary attachment to a battery, or a set of ring terminals, for permanent attachment. I use the ring terminals, then feed the other end of the connector up through the bike somewhere where it can be hidden. In my wife's PC800, the connector hides behind the right passenger footpeg. In my GL1500, it hides in the left passenger cubby. When I park the bike, I simply flip open the cubby, plug in the Battery Tender, and I know the battery is protected and maintained.

The Battery Tender is designed to be pretty much indestructible. You can hook it up backwards to the battery, and nothing will happen. You can start the bike with it connected, no problem, it simply turns itself off. It's spark proof, and has an indicator light that flashes and changes color to tell you the state of your battery, and what it is doing to manage it. It has a five year warranty, which I have not had to use.

The Battery Tender works great on standard flooded wet-cell lead-acid batteries, as well as AGM (absorption glass mat) batteries. If you have a gel-cell battery, there is a different version that has programming to work properly with them.

And you can now get accessories that plug into the Battery Tender vehicle-side connector when the Battery Tender is not connected. These provide USB charging outputs and 12 volt cigarette lighter-style power ports to allow you to plug your electronic devices into your vehicle. See more about these accessories here: Battery Tender USB Charger and 12 volt Socket

Overall, this is one of my favorite products, they work amazingly well, keep your batteries in top shape, and cost less than a quarter of the cost of a single new battery. I can't recommend them highly enough.

569 people found this helpful

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66 comments

Ryan

Saves you money and headaches.

December 26, 2017

Size: 12V @ 750mAVerified Purchase

Paid for itself the first use. Fantastic.

Accidentally killed a brand new car battery leaving a stereo hooked up in a car that sat for two weeks.
Drained that sucker down to 4 volts. :-0

Once a car battery is at 9v or lower, common knowledge is it has to be replaced. But sometimes newer batteries can be saved.

Apparently the key to saving a drained new battery is to trickle charge it back to life very slowly.

I let the tender charge it for a couple hours, unplugged it and finished charging the next day.
Battery took a full 13 volts and holds it well!
Yay battery saved!
If I would have jumped a battery that low it would have killed the battery and possibly the alternator.

Thing saved me like 80 bucks already.

Then I replaced a battery in another car, and found it wasn't quite charged all the way brand new.
Apparently even new batteries should be trickle charged before the first use to prolong the life.

Brought that one from 12.4 to 13.0 volts in a couple hours.

I haven't even got to it's intended use yet, which is to maintain a charged battery for long periods of time.

This could break tomorrow, and I'd still feel I've got my money's worth and buy another one.

22 people found this helpful

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Carlos Berguido

Does exactly what it promises to do very well

May 6, 2018

Size: 12V @ 750mAVerified Purchase

Our 2016 Honda Fit LX with KARR alarm is usually only driven once a week for a few miles, and now after 2 years and about 2000 miles, the battery is too discharged to start the engine if I forget to lock the car. Subsequent current measurements showed much less is drawn from the battery when the car sits with the doors locked than when the doors are left unlocked. Measurements also show that even with the doors locked, which is usually the case, the battery is below full charge most of the time, which is not a good thing for the life of lead acid batteries.

So the hunt was on for some device that would sense the car battery state, bring it to full charge, and maintain that charge automatically indefinitely, without requiring turning off and/or removing the charger. This Battery Tender Junior 021-0123 12 V 750 ma unit appeared to meet the requirements.

I was glad when the package arrived, because this meant I was able to start measuring voltage and current at the connected battery, to make sure the unit was doing what I expected it to do. The unit that plugs into the outlet has 10 feet of cord from the unit to the connector that attaches to either the about 2 foot cord of the clamp harness or the about 1.5 foot cord of the terminals. I decided on using the clamp on harness because it was just long enough for the connector to reach through the Fit front grill where I used a cable tie to hold the cord in place so I could tuck the connector back inside the grill while driving.

When first connected, the car battery measured 12.3 volts, which is below full charge. When powered on, the unit started flashing red during initialization, then switched to solid red. At this time, the voltage at the battery gradually increased above 14.4 volts, indicating the constant current charging bulk phase. After a while, the voltage dropped and the LED switched to flashing green, indicating the constant voltage absorption phase. Finally, the voltage dropped and the LED switched to solid green indicating maintaining a full charge.stage.

For testing, I used 2 digital meters, one in parallel with the battery terminals to measure DC volts, the other in series with the AC supply to measure current in 120 VAC ma. During this solid green indicating maintaining a full charge.stage,the DC volt meter shows 13.09 to 13.14 volts, while the 120 VAC used by the unit shows 3 to 50 ma, or at a 25 ma average, approximately 3 watts of 120 VAC power consumed. Of course, as the unit detects the parasitic drain on the battery by the alarm and always on car systems, the AC power consumed will rise to replace the drained energy. The unit did not feel warm after this short bit of testing.

Added 5/8/18. I noticed there is a second state while the light stays solid green, With my car's 12 volt AGM battery, after the trickle charge state indicated by solid green, the charger then enters a standby state with the LED still solid green, where the tender monitors the battery voltage, ready to trickle charge as needed. When this is happening, the meter reads a steady 13.12 volts instead of the 13.09 to 13.14 volts described above. I did not measure the power consumed in this standby state, but I would not be surprised if less than 3 watts is being consumed in standby.

I am satisfied that this product was designed well to do the job. I will update if anything changes this view.

5 people found this helpful

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Jennifer S.

LOVE IT!

May 10, 2019

Size: 12V @ 750mAVerified Purchase

I have two bikes, a Kawasaki Vulcan 800a with a high performance gel battery, and a Yamaha V-Star 950 Tourer with a (VRLA) Valve Regulated Lead Acid battery. The information on these batteries and how to charge them can be confusing or even a little scary. The Yamaha owner's manual was over-the-top with caution about charging the VRLA battery, even suggesting that you take the battery to a dealer to charge it. WHAT? That's stupid. Because of all of that nonsense, I actually contacted someone at the manufacturer to make sure that I was getting the right charger. I was assured that the Battery Tender Jr. would work for both of my battery types, but they also recommended getting the Battery Tender 800 (waterproof) Charger, if I was going to be charging my bikes outside. I don't. I have a garage, so I felt comfortable purchasing the Jr.
I can honestly say that this is the greatest "tool" I have purchased for my bikes in a long time. I am kind of mad at myself for not getting one of these SOONER. Why did I screw around with a regular charger for so long? This is a smart-charger. It takes all of the guess work out of charging, and it is SO EASY to use! I attached the pigtail connector to my 950's battery, connected it to the power cord, and plugged it into the the wall outlet. Done. It fully charged my battery and gave me an indication that it was done within 12 hours, from basically fully discharged. I used it again to charge the neighbor's John Deere rider mower's battery with the standard clips. Easy-peasy.
Right away, I ordered another pigtail connector for my 800.
I don't know why anyone wouldn't buy one of these. I am a convert. No more bulky charger for me! This thing is the shizzle!
Love, love, love it!

2 people found this helpful

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Kindle Customer

Great Charger, easy to use, works perfect.

April 3, 2016

Size: 12V @ 750mAVerified Purchase

Thes was just what I was looking for.
My son and I have a Polaris Quad (4 wheeler) and if it sits in the garage in the winter, the small battery tends to weaken over time.
This product is so easy to use.
It includes an extra connection wire that installs on the batter of the vehicle and stays there. To plug the charger into the vehicle, you don't need to access the battery, you just connect it to the wires that come with a nice, weatherproof connector.
Also, you can leave it connected all the time, whenever you're not using the vehicle. It has an overload protection so it won't over charge the battery.
No matter how cold it is, or how long it's been sitting, the battery is always fully charged.
From what I read, a fully charged battery will last longer, and the cost of the battery tender was very reasonable.

Thanks for reading

10 people found this helpful

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Bochco

Great Little Charger

December 11, 2018

Size: 12V @ 750mAVerified Purchase

I bought this charger to keep our convertible topped off while sitting for weeks at a time during the winter months. Usually the car will be hard to start after a few days of sitting, so we were using a regular battery charger to keep it up. This was a pain in the rear, so we bought this trickle charger. The install was easy and it came with everything I needed. This does include the charging adapter cord that attaches to the battery. The adapter cord also has a cap for it so it stays protected from the elements while you're driving around.
We hooked up the charger for the first time and the light on it turned solid red, indicating the battery is low (below 80%) and the charger is charging. After a short time, it went to flashing green indicating the battery is above 80% charge. Not long afterwards, it went to solid green which indicates the battery is 100% charged. Once it's solid green, you can leave it connected indefinitely. it will only supply enough output to keep the battery charged. If you have any electrical items that draw current when the car is off (such as an aftermarket alarm system which our car has), this charger will ensure the battery stays topped off and ready. We let the car sit for a week in sub freezing temps (in the garage as the charger isn't rated for outdoors) and when we went to start the car, it started like it was a hot summer day. If there are any drawbacks to this unit, I would have to mention that the connector is very tight to connect and disconnect, especially when it's cold. However, this is what you want. You don't want a loose electrical connection, therefore to us, it is not a negative.
We love this charger and highly recommend it!!

2 people found this helpful

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Eighch Dot

Perfect for Seldom-Driven Exotics...

November 28, 2017

Size: 12V @ 750mAVerified Purchase

So, I own one of these so-called "exotics"... you know the type handmade, too expensive to be honest about and temperamental as all get out. If you have prior experience with exotic vehicles, then you know their designers go out of their way to build "perfectly balanced" vehicles. While that is all arguable, one thing is for sure, they make some wild decisions on electronics and battery placement. In my case, the battery is INSIDE the cabin. **No bueno** What's worse, the battery sits behind a fully electronic passenger seat, under a ton of bulkheads and trim work. Taking it out can take an hour. The problem is, if you lose power, the chairs don't work... no access to the battery to change it!!! Don't mention the fact it has a battery disable switch that has to be reactivated with black magic and voodoo. Best to keep the battery in good shape.
Enter the Battery tender Jr. Love this product. Companies like Aston martin, Ferrari (name a hundred more) will sell you an "integrated" system running you over a thousand bucks to keep your seldom-driven car alive. Don't bother. Just get this and keep a smile on your face.

4 people found this helpful

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mqqn

Great product for the price - will save you many times the money in battery replacements over time.

January 20, 2018

Size: 12V @ 750mAVerified Purchase

Indespensible for the person with machinery / vehicles that have batteries. This is the single version of the larger Battery Tenders. These come in a blister pack with a harness designed to be mounted to the terminals of your battery for quick connect, as well as a harness with two nice quality "alligator clip" style connectors for "clamp-on" use. I have three of these - one on a Harley, one on a Kawasaki and one on my lawn tractor.

During the summer when I am riding and mowing I only connect the tender if I am not going to be using the bike or mower for a few weeks. Once the snow flies, all three get hooked up and I can rest easy knowing my batteries are being, well, tended to!

The unit keeps a charge on the battery until it gets "fully charged" and then switches to a "maintaining" mode which "exercises" the battery to keep it from sulfating (if applicable) and keeping the battery fresh and ready. This tender WILL extend the life of your batteries, particularly if you are a "park it and walk away" type of maintenance manager - that will kill a battery way before it's time.

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