Battery Tender Junior 12V Charger and Maintainer: Automatic 12V Powersports Battery Charger and Maintainer for Motorcycle, ATVs, and More – Smart 12 Volt, 750mA Battery Float Chargers – 021-0123

Battery Tender Junior 12V Charger and Maintainer: Automatic 12V Powersports Battery Charger and Maintainer for Motorcycle, ATVs, and More – Smart 12 Volt, 750mA Battery Float Chargers – 021-0123

Buy Battery Tender Junior 12V Charger and Maintainer: Automatic 12V Powersports Battery Charger and Maintainer for Motorcycle, ATVs, and More – Smart 12 Volt, 750mA Battery Float Chargers – 021-0123: Battery Chargers – ✓ FREE DELIVERY possible on eligible purchases

What are battery tender junior 12v charger and maintainer: automatic 12v powersports battery charger and maintainer for motorcycle features?

  • Make sure this fits by entering your model number.
  • Stay charged: battery tender battery chargers and maintainers provide a full charge to your powersport vehicle’s battery before switching to float mode to maintain proper voltage levels for safe, long-term storage
  • Extend battery life: compatible with all 12v lead-acid, flooded, agm, and gel cell batteries. Complete 4-step charging program (initialization, bulk charge, absorption mode, float mode) allows for optimization of battery power, without overcharging or battery damage
  • Includes: 12v, 750ma battery charger and battery maintainer with 12-foot output cord, fused-ring terminal harness for hard-to-reach batteries and alligator clip accessory cables, 5-year warranty, and lifetime customer support
  • Simple & safe: low maintenance, easy-to-use, universal battery charger is just 3.3 x 1.3 x 2.4 inches, 1 lb (charger only). Spark-proof circuitry ensures no-spark connections, and automatic reversed hook-up detection verifies correct connection
  • Monitor power levels: two-color charge status led light indicates the state of the charge and if the battery voltage drops too far under load, adaptive charging will resume full charger output power. Automatic charge cycle functionality switches to float mode after fully charging the battery
Categories: Automotive

Product guides and documents

Battery Tender Junior 12V Charger and Maintainer: Automatic 12V Powersports Battery Charger and Maintainer for Motorcycle, ATVs, and More – Smart 12 Volt, 750mA Battery Float Chargers – 021-0123 AMAZON

Buy Battery Tender Junior 12V Charger and Maintainer: Automatic 12V Powersports Battery Charger and Maintainer for Motorcycle, ATVs, and More – Smart 12 Volt, 750mA Battery Float Chargers – 021-0123: Battery Chargers – ✓ FREE DELIVERY possible on eligible purchases

Looking for specific info?

Can this be used to charge an agm battery?

Stupid me, but don’t all lead acid batteries use the same chemistry? I’ve read only that 6-cell lead-acid batteries should never use a charging voltage exceeding 14.4 volts, since water will begin to h2 gas and o2 gas above that. You risk explosion and loss of electrolyte beyond that. Explain why this is different for agm, flooded, and gel batteries!

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How is axtra 3.6 amp battery charger maintainer compare to battery tender 0.75 amp?

Our battery tender jr charges at .75 ma and the other mentioned charger looks to be a 3.5 amp charger.
Customer service
deltran usa

Is axtra battery charger maintainer better than battery tender?

We can only speak about our deltran products. Since the family started this company in 1965, deltran battery tender® has taken great pride in designing, manufacturing, and distributing technologically advanced products that meet the ever changing needs of our worldwide customers!
Customer service
deltran usa

It looks like axtra 3.6 amp battery charger maintainer is better than this one?

Yes, axtra 3.6 amp battery charger is better than battery tender 0.75 amp charger. Battery tender is overpriced charger for 075 amp. Axtra charger has 0.9 amp and 3.6 amp options to charge variety of 6-volt and 12-volt agm and lead acid batteries.

Looks like axtra 3.6 amp battery charger maintainer is better than this?

This battery tender is just that . It only is capable of an output .75 amps that’s 3/4 of 1amp, designed to maintain a good charge in a good battery. Keeping your battery healthy without overcharging. Auto shut off.

How fast does it work

I actually just used this to charge the battery in my 2009 jeep liberty when the ‘battery light’ came on. It’s been 20 hours and the battery is now full. Now, this unit is not intended to be a fast charger, however, it did get the job done without a problem. If you are looking for a speedy charge, go with an actual battery charger. Hope this answer wasn’t too late!

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Why is this not available in california?

California requires a more energy-efficient version. The ca-compatible 1.25a version is 022-0185g-dl-wh, also available on this amazon page. In fact, it now looks like all the tenders on this page are ca-compatible.

What issues will i have if i choose the battery tender that is 1.25 amps versus the 0.75 amps version? Thanks.

It’s a question of size, current and possibly time. Battery jr. Is smaller, i believe. It is mainly used in motorcycle and smaller battery applications. With lower amperage, there may be some longer times involved as well as working the charger more on heavy duty batteries. Both chargers have a solid reputation and will probably be up to the task. I would use higher amperages for automotive and truck applications and the jr. For motorcycle and smaller applications, unless size and portability are the over-riding factor. I recommend both units.

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Where do you get a negative extension cable? The manual says you need one when charging a battery outside the vehicle.

Not true….the power line on the unit is long enough, if you need longer use a bit higher wire gauge extension cord and you will be fine. My unit and another kind are keeping my two corvettes charged and ready to go.

Will this work with a john deere lawn tractor battery?

I hooked this up to a john deere d125 with a battery i just replaced. After an hour and the voltage up to 13 volts, which is okay, the red light is still on. It’s supposed to go to blinking green at 80%. Put in a question to battery tender, and no response yet.

I have a battery tender jr:plugged into a 120 volt source. I read 12 v ac on my fluke without battery hooked up to it. Will it convert to dc with atv battery hooked up to it ? Yes or no !!!!

That’s the idea behind any type of battery charger ac to dc. If i understand your question properly, you have the tender plugged into a regular ac outlet and are charging a 12v dc atv battery. It will work just fine.

Can this unit be connected to a 12v outlet inside the car instead of connecting it directly to the battery terminals?

No i don’t believe that would work because that terminal pulls power to charge your phone etc. You need to push power into the battery not pull power out.
A good automotive electrician could install a power point inside the vehicle to plug in your battery tender if you wanted but it’s not practical. Just hook it up to your battery.

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Is this compatible with a bmw 1200 gs motorcycle?

None of these actually answer the question. I used this charger on my triumph motorcycle with no problems, but now i have the bmw 1200 gsa, and bmw claims that anything other than their charger will cause an over-voltage situation that will damage the electronics on the bike, and void warranty. I am not sure i believe them, but the downside is very expensive, so i also question whether this will work on the bmw.

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Which one shall work on a battery with ah 100?

Battery tender 021-123 , no issues

Can this battery tender maintain the new lipo battieries?

No, it won’t work. It’s unable to read the state of charge. Battery tender brand is for lead-acid batteries, including agm-type.

How safe is this item to be able to trust it unattended? In terms of fire hazard or lack thereof.

My experience is that it will be fine. It is designed to be unattended, switching from trickle to float. When the battery is fully charged, the charger turns off until the battery drops below a preset voltage. I have two and they are always unattended.

Why the output of charger measure is 0v when no connection but led show works? Is this normal or damaged?

the output clips or ring terminals must be connected to
a battery before the charger can produce an output

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Can i use this for my 2004 mercedes sl500?

I cannot see why not. Just remember this a trickle charge that it will keep your battery charge. Some people think it is a charger and in 20 minutes your battery would be charged. It is not designed to do that. It is intended to keep your battery top off so to speak.

Will this work to charge a lithium battery? (some conflicting responses on the answers section for this product)?

Over all i would say no. It would not charge the battery fully. A full charged regular battery is 12.6 volts. A lithium battery fully charged is 12.8 volts. The output of of the charger isn’t high enough to fully charge a lithium battery. So it would never be fully charged.

If this unit is plugged in upside down do i need to reverse the polarity of the cables at the battery or can the unit safely reverse polarity?

It doesn’t matter… The rectifiers in the unit will only allow the charging voltage to be put out in the correct polarity… You are converting ac to dc via a step down transformer then through a rectifier circuit which will only allow the correct polarity to be put out regardless of how you plug it in… However… The manufacturer strongly discourages modifying the plugs in order to make it fit into a non polarized recepticle… Get an adapter from the nearest hardware store…

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Battery Tender Junior 12V Charger and Maintainer: Automatic 12V Powersports Battery Charger and Maintainer for Motorcycle, ATVs, and More – Smart 12 Volt, 750mA Battery Float Chargers – 021-0123 AMAZON

Buy Battery Tender Junior 12V Charger and Maintainer: Automatic 12V Powersports Battery Charger and Maintainer for Motorcycle, ATVs, and More – Smart 12 Volt, 750mA Battery Float Chargers – 021-0123: Battery Chargers – ✓ FREE DELIVERY possible on eligible purchases

What are our customers saying?

5Expert Score
A required purchase if you own a harley!

I’m now on my fifth harley and i’ve always used deltran battery tender junior to keep my batteries charged. I just bought my third battery maintenance tender since 2000 and they’ve extended the battery life on each of my harleys. My longest lasting battery started my road king countless times over a six year lifespan. My friends that use a battery tender have had the same experience with all of their bikes. The only time i’ve seen a battery tender supposedly “fail” was on a friend’s harley…the light would never switch from red to green indicating the battery was fully charged. He ended up replacing his battery and when he placed the tender onto the new one, the indicator switched from red to green in less than thirty minutes. The battery tender worked exactly as it should have on the old, defective battery.

5Expert Score
Keep my car always ready to go.

The description says these aren’t for automobile charging… But they will charge an auto if you have the time… And for your extra vehicle that doesn’t make it out much, you may have a day or two to charge it. But then once it is charged just put this trickle-charger on it and your vehicle will start even if you leave it sitting a couple months! I love the feature that prevents over-charging so you can just leave this attached all the time.

5Expert Score
Great little charger

This is fifth charger i’ve purchased. I have a larger capacity battery tender for my truck, 1 each for my wife’s car, my tractor and gator. This new tender is for my generator. I’ve never had a problem with any of them. They maintain the battery for my vehicles and equipment when they sit for months in the off season.

5Expert Score
Extends the life of any battery

Battery tender is exactly what it says. Todays new cars with all the electronics that they have on them puts a constant drain on your battery. When i’m not driving my cars or motorcycles i use battery tender to keep them fresh and ready to go.
By the way i highly recommend the brand name ‘battery tender’ for best quality and performance.

5Expert Score
Perfect battery charger very compact works well

Perfect battery charger very compact works well. Does what it supposed to do replace a more expensive harley davidson charger with this charger. Battery tenders have great reputations and last long time junior doesn’t have all the bells and whistles but it does what it supposed to do and the light on the front gives you a good indication of charging or fully charged that’s all you need. Would highly recommend

5Expert Score
Great product

This is a great product, i will order another.
The cord is a little short for where i park my bike, but i made it work. My battery was completely dead, it charged it to full over night. So if you are looking for a battery gender and charger in one…look no further.

5Expert Score
Works as they say

I own 5 and never had a problem with any of them. I use one on my lawn tractor the battery warrinty is only good for 6 months the battery is going on 6 yrs old.

5Expert Score
Works great

Keep hooked up to my atv. Have been using these on my motorcycle for years and these work perfect. Keep my batteries at full charge so my equipment is ready whenever i am. Would highly recommend to anyone who has toys that the need to keep the batteries at full charge.

5Expert Score
Works great maintaining battery on my subaru!

Subaru had a problem with 2016 outback’s (and think a few years either side too) with battery drain when the car wasn’t used regularly. Previously i was using a regular battery charger with a built in regulator to step down the voltage as the battery became charged. Worked ok but sometimes the terminal clamps became loose and when one would go to use the car … Disappointment. The battery tender has connections to make it very easy to attach permanently to the car’s battery cable terminals with a lead wire that unplugs from the ac portion of it. Offset plug connections on the lead prevent mixing up positive and negative situations. Well thought out system and i would buy again.

5Expert Score
Plug and play. Simple instructions.

Product is exactly what description states. This works wonderfully with my 2022 harley and its built in tender adapter. And by far cheaper than any comparable harley product. Comes with the adapter type cable and standard clamps. The cord has plenty of length. Simple, easy to follow instructions.

4Expert Score
Small, easy to use, and effective

Simply put, this trickle charger is great: simple, easy to set up, easy to use, easy to put away, and gets the job done.

I bought this charger to keep my lawn mower battery charged over long absences. I was amazed that the box it came in was so small, and began to wonder if i had made a bad decision, or if i had been shipped the wrong model. I’m happy to say that neither of the above were true.

I’m also happy to say that this was extremely easy to set up, and put away when i moved.

4Expert Score


4Expert Score
Worth the money

I hardwired this to my honda 3,000 whisper generator. Working good so far but only time will tell.

4Expert Score
Simple easy install and a plug and play product

Had ordered another brand to try something different, but my mistake! I returned the junk charger i originally purchased and order this battery tender. A tried and true product. I have 2 others that have worked flawlessly for the last 5 years. I highly recommend this product for anyone looking for a simple battery tender for long term or short term storage.

4Expert Score
Easy to install

Easy to install. I use it on a vehicle i seldom drive, but when i get in it it’s ready to go.

4Expert Score
Works great

Exactly what i needed on my zero turn hustler mower. Will be great for winter storage also.

4Expert Score
California legal battery tender jr 021-0123

This is the new version of the deltran battery tender jr that is listed as an approved energy efficient device.

My previous tender was the same make and model, but used a transformer. When trying to replace it i found some sites said ‘not available in ca’. Some places also had ridiculously high prices.

It was a heavier little beast that used a transformer and california said used too much current for its use case. So deltran brought out this newer version of the battery tender jr. That used solid-state devices and no transformer to change ac to 12vdc.

As many others do, i’ve got the fused ring terminals to sae connector attached to my bike, and hook it up when i park. It seems to work as well as previous tenders i’ve used, though it feels like there’s *nothing* inside.

This is, as all tenders are, a charger, but all chargers aren’t tenders. My bike doesn’t get as much use as i like, but the 0.75a current brings it up to snuff quick enough and then switches to a very low maintenance charge, unlike typical chargers and trickle chargers. This keeps your battery alive instead of cooking it dry. It’s advertised as being able to stay connected for months at a time without harming the battery. If it’s in good shape and you don’t live in bitter cold, putting the tender on once a month for a few hours might save even more watts. This unit is more tender than charger.

It’s rated to charge a maximum size battery of 55ah. That could take awhile with it’s low current. If you go out to the car on a work morning and are greeted by a dead battery, you’ll want something with more juice to get you on the road. But if cold weather just makes your battery sluggish in the morning, putting this tender on when you park at night should do the trick.

While the instructions (and some reviewers) give the impression that the 021-0123 tender jr is for lead-acid batteries only, it’s equally appropriate with agm (absorbed glass mat) batteries, which are lead-acid also, and gel batteries. Other formulations such as li-ion and li-fe that need a *different type* of charger, and it looks like deltran has one for those as well.

The deltran vehicle harness is fused at 7.5a. Many devices like heated gear or tire inflators need more juice and will blow a fuse that small. The wiring will easily handle 15a and possibly (proceed at your own risk) 20-30a for a short period. But the tender will not, so make sure the tender sees the small fuse as required.

I’ve been happy with the tenders i’ve owned, but their customer service is potentially very restrictive, so minus one star there. But if this lasts 5yrs and a day, i’m ok with that.

4Expert Score
Worked on motorcycle, not so much on a very flat car battery. Customer service very good!

Picture: failed capacitor.

I have the ring terminals permanently installed on my motorcycle. It charges that battery very well. Works as expected.

Car (lexus rx350) wouldn’t start. The battery was flat, i presumed, so i connected it to this charger using the alligator clips. The next day, when i checked on it, the led was off. (this is not one of the four possible options – red, green, red flashing, green flashing). Weird, i thought the breaker tripped or something, so i unplugged and re-plugged it in. It began charging (solid red) again. I watched it for 3 hours and it continued on solid red. Perfect, i left it overnight again.

The next day, again, no led. This time, unplugging did not fix the issue. I emailed deltran customer support with my problem and they quickly sent me another one so long as i destroyed this one (cut the cable off) – i guess in case i was lying, and wanted 2 chargers for the price of one. Anyway, after i did so and they sent another, i decided to do some sleuthing.

Unscrewing the 3 screws on the back, i noticed a strong smell of ‘the magic smoke’ that comes out of electronics when ‘the smoke just wants to come out.’ (this is a joke. Laugh) one of the capacitors was bulbous and as a result, ‘leaned’ over slightly as you can see in the image. I suspect as a result of overheating, could be wrong. But i found it interesting that the over-temperature circuit (if there is one?) did not prevent it from destroying itself while charging a battery that was perhaps too large for this charger.

Regardless — great charger for motorcycles and small batteries like lawn tractors, etc. But for a car, probably not recommended if it’s very flat.

Fyi i have purchased a (significantly) larger charger for the car, and 24h later, it’s still charging, so it’s either fully dead or seriously discharged. We shall see. (it’s not that this charger can’t do a car, but it’s just that particular battery is asking a lot of any charger.)

4Expert Score
Works as stated

Rejuvenated my battery on my atv, that i had let set to long. Saved $250 by not having to buy a new battery. Still tending after 30days

4Expert Score
Liked it bought another one

Easy plug long cord

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