Best Battery Tender

Last Updated on September 1, 2020

Ending up with a flat battery after leaving your car unused for an extended period of time can be a frustrating experience. Relying on jumper cables isn’t the best resolution to such a problem, because you can’t assume that there will always be someone around to help give your car a jump. While carrying a spare battery might not be the worst idea, it’s still quite a cumbersome affair.

Investing in a battery tender will eliminate the need for jumper cables or backup batteries by providing a continuous flow of charge to your battery when not active. Not only that, but it will help lengthen the life of your battery and maintain its peak performance for years to come.

Check out the quick list below for links to customer reviews and prices for my picks or read on for the full review:

  1.  Battery Tender 022-0165 DL WH
  2.  NOCO Genius G3500
  3.  Battery Tender Plus 021-0128
  4.  Stanley BC15BS
  5.  Battery Tender 021-0123

A battery tender is a device that transfers power from a standard AC outlet in the form of amperes to your battery which maintains its operational state through long periods of inactivity. Battery tenders are microprocessor controlled, which grants it the ability to perform multiple charging functions without damaging the battery. Most battery tenders are light in terms of weight, making them extremely portable.

Battery tenders require an average charge time of 2 to 10 hours to fully charge your battery. Leaving your battery connected to a battery tender for more than that will not take from its capacity or affect its health negatively. Bear in mind, not all battery types can be charged using a battery tender. Make sure that you’re aware of your battery type first so you can purchase the appropriate charger for it.

Battery Tender vs Battery Charger

Leaving a battery charger connected to your vehicle for a prolonged period of time will result in an overcharged battery, which ultimately degrades the performance of the battery and can definitely damage it or render it useless.

Alternatively, a battery tender slowly sends a trickle charge over a specific period of time to get a sense of how much of a charge the battery requires. After fully charging the battery, the battery tender will cease sending any more charges. Which means that your battery won’t be overcharged or run the risk of damage.

How to Best Use Your New Battery Tender

First time using a battery tender? Here’s a complete guide on how to properly utilize your battery tender.

First and foremost, put on cloth and eye protection and avoid any contact with water or soap. Also, make sure that you’re in a ventilated area before moving forward.

Try to maintain a distance between the charger and the battery, that, of course, is governed by the length of your cable. Also as a safety precaution, keep the charger’s cables away from any moving objects.

For a positively grounded vehicle, join the negative black clip with the negative terminal of the battery and join the positive red clip with the chassis of the vehicle.

For a negatively grounded vehicle, join the positive red clip with the positive terminal of the battery and join the negative black clip with the chassis of the vehicle.

Plug your charger into an electric outlet then turn it on. Now, observe the light indicators on the charger to find out the status of the battery.

    Flashing Red Light: the charger is on and the microprocessor is functioning ideally.

    Steady Red Light: the charger is proceeding to charge the battery.

    Flashing Green Light: battery is 80% charged or more and ready to be used.

    Steady Green Light: battery is fully charged.

Best Battery Tenders

Are you wondering which battery tender you should purchase? Look no further, we’ve taken the time to try out a number of products and have compiled a list of the best battery tenders on the market.

Battery Tender 022-0165-DL-WH

This unit is one of the most popular ones on the market because of the wide range of applications that it offers, from automotive powering all the way to marine battery charging.

This is a completely sealed and maintenance-free device that possesses dual charging stations, each delivering 12 volts at 1.25 amperes independently, allowing it to charge more than one battery at once.

With an array of safety measures like being spark proof and having a reverse protection feature, this device sets the bar high. Also, temperature variation will not affect the charging performance of this unit by virtue of its temperature compensation feature.


  •  Highly affordable 
  • Dual charging stations
  • Temperature compensation
  • Reverse polarity and spark proof
  • AGM and Lead Acid compatible
  •  Short power cord
  • Not for gel batteries

NOCO Genius G3500

This unit excels when it comes to safety as it is designed to protect against overcurrent, overcharge and overheat. Also, it’s spark proof, water resistant and equipped with reverse polarity protection.

This device supports both 12v and 6v batteries at a super fast charging speed. The G3500 can be used as a maintainer for starter or deep cycle batteries. It’s also capable of reviving heavily sulfated or dead batteries.

The G3500 is a compact and lightweight unit that is easily portable. The two additional mounting holes help avoid any mechanical trouble and the rubber base helps against slipping.


  • Low energy consumption
  • Portable lightweight design
  • Supports 12 Volt and 6 Volt batteries
  • Spark proof 
  • Water resistant 
  • A bit noisy
  • Slow charge speed for large batteries

Battery Tender Plus 021-0128

This unit comes bearing 50% more power than its junior model. The technology that this unit provides is designed primarily for lead acid batteries, which means that not all battery types can be charged by this device.

The device switches into maintenance mode once your battery is fully charged, keeping the voltage at an appropriate level. That process takes place by using a self-timer that will initiate the float charging mode within 72 hours of the battery being plugged.

Along with a 4-stage program, reverse polarity and spark proof protection, it’s safe to say that the Tender Plus is a very well rounded device to use for maintaining the health of your battery.


  • Portable and easy to use
  • Rugged metal construction
  • Spark proof and reverse polarity


  • Not compatible with all battery types


Stanley BC15BS Battery Tender

This tender charger is an ideal unit for overcoming a dead battery situation as it is capable of feeding 40 amps to a vehicle’s engine to help it start. This unit comes with three charging modes, rapid charging, top-off charging and trickle charging. Moreover, this device is available as a 15 amps model or a 25 amps model.

The Stanley BC15BS features an LCD screen that helps with monitoring the status of the battery, which is an improvement from the LED indicators that most chargers use.

To the right of the screen, there are four buttons that offer a few quick options like engine start, battery voltage, alternative check and battery recondition. The alternator check determines whether the charging system is functioning properly or not.


  • LCD display panel
  • 40 amp engine jumpstart
  • Four buttons for quick options
  • Three stage charging program
  • Works for AGM, Gel, and Wet Cell Batteries
  • Large

Battery Tender 021-0123

This reputable unit is one of the top tiers on the market in terms of quality and performance. Fully automatic and microprocessor controlled, ensuring a fully charged and maintained battery through a multi-step program.

The Tender 021-0123 is compatible with all 12v lead acid batteries. It also supports sealed and flooded batteries like AGM and Gel batteries. Further, it’s capable of reviving dead batteries safely.

The indicator lights on this device will keep you informed about the status of your battery during every stage. The compact and lightweight design makes this small charger easily portable. All in all, this is a highly recommended tender charger.


  • Very affordable
  • Four step charging program
  • SuperSmart charging technology
  • Compact and lightweight
  • Compatible with most batteries
  • Can get hot

Picking one of the reviewed products might get a bit too tricky since they all share a lot of fundamental features. However, our number one spot for the best battery tender has to go to the NOCO Genius G3500 because of its outstanding compatibility and its ability to support both 12v and 6v batteries. Not only that, it has shown to be a prime example of safety and top notch performance.

In the second place, an absolute beast of a charger, the Battery Tender 021-0123. For an amazing array of features and an astounding amount of power to come at such an affordable price, no wonder why this is a popular choice among users.


Have you found our information useful? Let us know which one of these products you think is the best for you.

Share on facebook
Share on twitter
Share on pinterest
Share on email
Share on print

Leave a Comment

Your email address will not be published. Required fields are marked *