Product Specifications for Battery Tender Plus 12V 1.25 Amp Battery Charger & Maintainer
| BM Part #: | 021-0128 |
|---|---|
| Brand: | Battery Tender |
| Voltage: | 12 Volt |
| Charging Rate: | 1.25 Amp |
| Input Voltage: | 120 VAC 60 Hz |
| Length: | 4.87" |
| Width: | 3.25" |
| Height: | 2.93" |
| Shipping Weight: | 4.30Lbs |
| Warranty: | 10 Year |
| Product Manual: | Download |
| Datasheet: | Download |
What's in the box:
- 12V, 1.25 AMP battery charger with LED status light to show battery status
- Fused ring terminal accessory cable for hard to reach batteries
- Fused alligator clip accessory cable for an alternate connection
- 10-year warranty and lifetime customer support
- Smart 4-Step Charging: Automatically moves from bulk charge to float mode, no manual switching required.
- Wide Battery Compatibility: Works with flooded, AGM, and gel cell 12V batteries from 14Ah to 80Ah.
- Dual Connection Cables: Includes both alligator clips and a ring terminal harness for quick, repeat hookups.
- Reverse Polarity Protection: Alerts you and shuts down automatically if clamps are connected backward.
- 10-Year Warranty: Backed by the longest warranty in the battery charger industry for lasting peace of mind.
- Compact, Durable Housing: Measures 4.87" x 3.25" x 2.93" and weighs just 1.45 lbs for easy storage.
Product Description
Is your battery dying every spring after sitting all winter? A regular trickle charger can't fix that—it just pumps out constant current whether your battery needs it or not, which cooks the plates and shortens its life. The Battery Tender Plus 021-0128 was built to solve exactly this problem.
This 12V, 1.25 Amp smart charger reads your battery and adjusts on its own. It fully charges, then automatically switches to a gentle float mode that holds your battery at peak voltage without ever overdoing it. Plug it in and forget about it—for a weekend or an entire winter.
How the 4-Step Charge Works
Instead of blasting one steady current, the Plus moves through four stages:
- Initialization: checks battery condition and confirms correct polarity before power flows
- Bulk Charge: delivers full 1.25 Amp output to restore capacity fast
- Absorption: tapers current as the battery nears full charge to prevent heat and gassing
- Float Maintenance: trickles in just enough current to offset natural self-discharge, indefinitely
One Charger, Almost Every Battery
The Plus handles flooded, AGM, and gel cell batteries from 14Ah to 80Ah. That covers cars, trucks, motorcycles, ATVs, UTVs, boats, snowmobiles, and lawn equipment—so if you've got more than one vehicle sitting in the garage, this one charger can maintain all of them.
Built to Protect Your Battery (and Your Investment)
Sulfation—the hardening of lead crystals on a battery's plates—is the #1 cause of premature battery failure, and it happens fastest when a battery sits discharged. By keeping your battery at proper float voltage around the clock, the Plus helps prevent sulfation before it starts, which is why owners often stretch battery life from 2-3 years to 5 or more.
It also comes with real safety features: reverse polarity protection, spark-free connections, and a design that won't damage sensitive vehicle electronics. Backed by a 10-year warranty, it's a charger you install once and trust for the long haul.
Ready to stop replacing batteries every spring? Add the Battery Tender Plus to your cart and give your battery the charge it actually needs.
Frequently Asked Questions
What vehicles and batteries is the Battery Tender Plus compatible with?
A: It works with any 12V flooded, AGM, or gel cell battery between 14Ah and 80Ah, which covers most cars, motorcycles, ATVs, boats, lawnmowers, and other powersports equipment.
Can I leave the charger connected for weeks or months at a time?
A: Yes. Once the battery reaches full charge, the unit automatically switches to float mode and maintains proper voltage without overcharging, making it safe for seasonal storage all winter long.
How do I hook up the charger to my battery?
A: Connect either the included alligator clips or ring terminal harness to your battery terminals, then plug the charger into a standard wall outlet. The indicator lights will show charging status automatically.
Will this charger overcharge or damage my battery?
A: No. Unlike a basic trickle charger, the Plus uses temperature-compensated, multi-stage charging that tapers current as the battery fills, so it won't overheat or overcharge the battery even if left connected indefinitely.
What's included in the box?
A: You'll receive the Battery Tender Plus charger, a combination alligator clip and ring terminal cable, and an instruction manual to get you started right away.
Cross Reference & Compatibility
Customer Reviews
battery mart has been a great source of my batteries, this charger is working fine.
The battery tender works great. It is well designed and fits in the engine area of my very well. There are some
little lights on the battery tender to let you know if the battery tender is charging or if the car battery is fully charged.
Super fast shipping. After frying, my battery from using an inferior product. I decided to just stop playing around.
Great trickle charger
Just what the Dr. Ordered. Excellent!
After a problem happened I finally got this charger to work. The problem is in the pigtail HD motorcycle has on/or hooked to battery. I took the seat off and hooked the pigtail that come with the charger to the battery and run it out by HD's plug. Seems to work great.
Installation was easy, works fine so far
