Product Comparison: Battery Tender Junior 021-0123 vs Battery Tender Plus 021-0128

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General Specifications
Battery Tender
Battery Tender
Junior 021-0123
Plus 021-0128
About the Product
The Battery Tender® Junior offers much more than a trickle charger could offer. It has a brain. It's lightweight, compact, and fully automatic; very easy to use, especially in small spaces. It will keep your battery fully charged so that it is ready to go when you are!
The Battery Tender® Plus is a 1.25 amp battery charger designed to fully charge a battery and maintain it at proper storage voltage without the damaging effects caused by trickle chargers. Included is a quick connect ring terminal harness for hard to reach areas and alligator clips for an alternate connection.
Key Specs
Output Current
750 mA
1250 mA
Output Voltage
6V, 12V
Compatible Batteries
AGM, Gel, Lead-acid, Flooded, MF
Lead-acid, Flooded, MF, AGM, Gel
Recommended Capacity
30 Ah
40 Ah
Output Cord
12 feet
12 feet
What customers say about "Key Specs"
Battery Tender Junior 021-0123 Battery Charger
  • Just the Ticket for my lawn tractor, put the lugs on the battery terminals and charges like a dream. When I want to use the tractor I disconnect the connector and use the cap that comes with it in the end and start the tractor up.
  • Charging voltage is temperature compensated. It increases the charge voltage when it is cold outside and decreases the charge voltage when it is hot.
  • The Battery Tender works great on standard flooded wet-cell lead-acid batteries, as well as AGM (absorption glass mat) batteries.
  • Cables are short, so unless you’re arms length from the vehicle, you need the extension.
  • Impossible to connect to car batteries that do not have raised terminals.
Battery Tender Plus 021-0128 1.25 Amp Battery Trickle Charger
  • Excellent battery charger to keep my lead acid batteries topped off. As mentioned AGM requires a different charger that is optimized for it, whereas this charger is what you want for lead acid. I charge my motorcycle, and both cars with it.
  • Works, as promised, with lead acid (including AGM) batteries. This is the second one that I've owned and is connected directly to the battery of a 2014 model year automobile.
  • I don't use that car too often, so this keeps the system topped off nicely. It is compatible with the AGM battery that is OEM to the car. I've also used this to fully top off my Land Cruiser's SLA battery.
  • I've wanted to buy a battery tender for years. I finally bought two of them for two motorcycles. If you have an AGM battery, you'll definitely want one of these. Now my bike kicks over quickly even if it's been sitting for a couple of weeks in the winter.
  • Probably a great product. HOWEVER my VMAX MR127 12 Volt 100Ah AGM Deep Cycle said not to use anything less than 6 amps to change it.
Size & Weight
3.41 in.
4 in.
2.39 in.
11 in.
1.9 in.
11 in.
1.8 lbs.
3 lbs.
What customers say about "Size & Weight"
Battery Tender Junior 021-0123 Battery Charger
  • The new unit is so light weight it almost seems hollow inside.
  • Light weight and shutting down when fully charged.
  • These are small, light weight, and do their job. We use these on car , quad, mower, and motorcycle batteries when they sit in the winter.
  • The unit is pretty solid in build and has a solid weight to it.
Battery Tender Plus 021-0128 1.25 Amp Battery Trickle Charger
  • This is a great small battery charger.
  • It's smaller, lighter in weight, easier to use.
  • The charger is very easy to use, compact and light weight. The cables are long enough to reach the battery easily.
  • Small and light weight. Easy to use. Good indicators on charging status and battery charge.
Start Voltage
2 V
2 V
Charging Steps
1 - Initialization, 2 - Bulk Charge, 3 - Absorption Mode, 4 - Float Mode
1 - Initialization, 2 - Bulk Charge, 3 - Absorption Mode, 4 - Float Mode
Back Current Drain
1 %
0.5 %
IP Protection
Reverse Polarity Protected
Spark Proof
Automatically switches to float / maintenance voltage after fully charging the battery., If the battery voltage drops too far under load, full charger output power resumes., Solid state two color LED indicates stage of charger, Safety timer: 80 Hrs
Temperature compensated to ensure optimum charge voltage according to ambient temperature, Automatically switches from full charge to float charging mode, Reverse Polarity Protection to ensure user safety. Red & Green Lights Alternately Flash in this condition, Safety timer: 72 hrs
What customers say about "Features"
Battery Tender Junior 021-0123 Battery Charger
  • Easy to see lights that inform you of charge process.
  • Auto off feature sp you don't have to worry about ruining your battery.
  • Easy hookup once you have the ring terminal harness hooked up to your battery/batteries. no more fumbling around with alligator clips an having to open your hood to charge.
  • Spark free circuitry is nice (won't spark if alligator clips are accidentally touched together; note that a spark is still possible when connecting alligator clips to the battery).
  • No danger of attaching the wrong positive/negative -- it has reverse polarity protection
  • The charger unit doesn’t appear to be waterproof or encapsulated. I don’t recommend leaving it outdoors or year-round in an unheated garage.
  • Will not charge a fully dead battery.
Battery Tender Plus 021-0128 1.25 Amp Battery Trickle Charger
  • It is a bit slow, but I like the built in safety features that allow me to keep my battery fully charged while my car is in storage.
  • Bought 2. The feature I liked on this is that it does NOT shut of after 30 minutes so I can keep my summer sports cars charging all winter
  • Another handy feature is that LED indicator instructions appear on the unit. How thoughtful! This information is very helpful. Yet you don't have to dig for the manual.
  • I used this on a dead battery. It didn't completely charge until I realized I needed to add some distilled water to the battery. The feature that shows the state of charge (green light) was thus very useful.
  • This unit is not waterproof due the vents on top, so I put it up on a piece of wood to keep it off the floor, and shielded it with an inverted bucket in case it rains.
Warranty / Certifications
Manufacturer Warranty
5 year(s)
10 year(s)
Other Information
69.95 $

Price History

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