I purchased 4 of these as I have had battery tenders over the years and they worked flawlessly, not these new ones made in CHINA (JUNK!). I noticed that the red light was on all the time (charging) and it should only stay on for a short while than when battery is charged it goes to green. I checked the voltage output and found only putting out 9.01 vdc (should be over 12vdc), called customer service and they wanted to charge me a "warranty return fee" and possibly other chargers also on top of shipping charges to get the faulty product back to them.-these are less than 9 months old! The cost to have this item warrantied far exceeds what I paid for it. To bad, battery tender USED to be a great way to keep batteries at optimum condition, I had to go out and purchase battery minder units to use in stead. I AM REALLY DISAPPOINTED IN YOUR POOR QUALITY AND LACK OF WARRANTY TO STAND BEHIND YOUR PRODUCT BATTERY TENDER. I hope others may read this and not make the same mistake I made.BUYER BEWARE!

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.

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.

I have three of these now. They keep my riding mower or ATV battery charged in the winter. I was buying a new battery every spring until I got this. I use the other ones on a car I don't drive often and on another car that sits outside in the winter and I have no problems starting them no matter how long they sit. Occasionally I forget it's there and the connector that can be used to change the type of leads acts as a break away. I know it's not intended for that, but I also don't intend to back away with it still plugged in, it just happens sometimes.

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

I've had several of these over the past 12 or so years and still have all of them and all of them are still in working order. I've even partially driven over one of them with my car and it still functions perfectly. I just bought this one for a back up generator at work because the one someone had bought before stopped working and of course, left us with a dead battery when we needed it. :(

I've used them on motorcycles, and 4 wheeled vehicles as well as boats and not an issue! If you want something to keep a good battery good, this is it! If you want to charge a bad battery, this is NOT it!

"Made in China" is a bummer! I wish more American companies could afford to build stuff here.