When to Use a Battery Tender or Maintainer

Every type of vehicle needs power to start the engine and operate any electronics, and it derives that power from the battery. Just starting the car on a regular basis can keep the battery charged, so it should come as no surprise that a car that the owner rarely drives — such as a vehicle in storage — may end up with a battery problem. Fortunately, this issue is avoidable, as battery tenders can keep any car battery charged at all times. Here’s how battery tenders work.

Save the trouble of having to replace a battery in the spring, buy a battery tender for your motorcycle when you store it.

Battery Tender vs Battery Charger

A lot of people aren’t sure what makes a battery tender — which is also called a battery maintainer — different from a charger. The main detail to remember is that a battery charger typically sends a constant charge to the battery, with no regard to whether it actually needs to continue being charged. This means it’s possible to overcharge the battery with a charger — which can result in damage to the battery.

On the other hand, a battery tender can sense how much of a charge the battery needs, so it slowly sends a trickle charge to it over a period of several hours. It stops sending a charge once the battery is full. The result is that a battery tender won’t overcharge the battery like a charger might, which can help extend the life of the battery overall.

Using a battery tender or maintainer on your car while it’s in storage could save you from having to replace the battery.

The Best Time to Use a Battery Tender

Clearly, the main advantage of battery tenders is that they won’t overcharge the vehicle’s battery. This makes them perfect for keeping car batteries charged up while the vehicle is in storage. After all, leaving a battery charger connected to a car for months will overcharge the battery, but leaving a battery tender connected for that long is fine because charging will simply stop once the battery is full. This way, car owners can be sure their battery will be fully charged and ready to start the car even after spending months in storage.

Whether you’re about to put your car in storage or have noticed some signs of a bad battery in your vehicle, it may be time to give your car the extra attention it needs.

The contents of this blog are for informational purposes only and are not intended for diagnosing. Gold Eagle Company does not guarantee - expressed or implied - any specific results and a professional should be consulted on more serious issues.

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14 Comments
  • I have a 2000 cadillac eldorado since August, 2018, twice the battery has been completely dead after leaving it overnight.
    Mechanic did diagnostics, said something is draining the battery when car is off but couldn’t find it. Could I use a battery maintainer every night instead of paying lots of money for someone to find out what’s draining battery?

    • Hi, Ann. A good quality battery trickle charger (or maintainer) can be used every day. However, if the battery is losing its charge faster that then tender can keep it up – due to battery failure or something overly draining it, this will not help. Perhaps further tests conducted by certified mechanic may be useful to see what is actually causing this issue may be the next best step.

  • my car is parked outside and most of the time here in winnipeg canada the temp is as low as -30C will a battery tender still worked in these temp. thanks

    • Use a battery warmer

  • THANK YOU FOR SUCH A STRAIGHT FORWARD AND EASY TO UNDERSTAND EXPLANATION.

  • i have a 2007 Audi A6, i go away for 5 months and when i return to s florida, the battery is dead, i have bought 3 new batteries in 3 yrs from audi service and now they want me to buy another battery plus a battery maintainer, can you give me comment on this, i plan to take this up with Audi headquarters, because the service i got here in WPB was horrible and misleading, i will go out and buy a battery maintainer, can you please help me with this problem, i would be forever grateful, thanks

    • Hello, in this particular situation it might be best to consult with a professional and expert in this specific area. If you have any other questions please contact our Consumer Support Team at producttechsupport@goldeagle.com.

    • if your car will sit for months without use, its best to simply disconnect the battery

      • If you do that to many cars (especially Audis), expect an expensive trip to the dealership to recode some of the components in your car. Ironically, that list includes the battery itself! 🙂 It’s important to connect a memory saver when disconnecting the battery from an Audi (even for necessary car repairs).

        When replacing batteries on cars like Audis and BMWs (which have “intelligent battery management”), it’s important to use fully-charged batteries (trickle-charge them with a battery tender until at 100%), then swap the batteries out while using a memory saver to prevent your electronics from forgetting important information (and I’m not talking about radio presets!). I don’t know why Audi made it so complicated but it’s all necessary.

    • Check to see if the vehicle has a fuse labeled as “IOD” or ignition-off draw. If you store the vehicle without pulling this fuse, it will drain the battery. Today’s vehicles typically draw power from the battery constantly, for computers, entertainment systems, all those bells’n’whistles. This relies on the vehicle being started and driven regularly so the battery can keep up with the demand. When stored, the battery is fairly quickly depleted.

      This may help but batteries are physical mechanical things and need maintenance, replacement, and often just die if not properly maintained.

  • My jump starter shows 12+ volts, but it is only a surface charge — it will not start my car. A load test drops the voltqage to zero. If I replace the agm battery in the jumper, can I use a tender/maintainer to keep the jumper at the ready?

  • I thought that it was interesting when you said that one thing to consider when you are needing to charge your car battery is to use a battery maintainer instead of a standard battery charger since the maintainer will be sure not to overcharge your car battery and damage it. I have been thinking about getting a new car but I have been worried that I would charge it incorrectly and cause internal damage. I would be sure to purchase a battery maintainer so that I wouldn’t have to worry about damage or extra expense.

  • I do maintenance for a local fire department. they have a vehicle that has modems and computers along with flash light battery chargers that require staying powered up all the time. they equal almost 2 amps of draw. I have tried a battery maintainer that will charge at 5amps then float. Once the battery drops back down the maintainer will not start charging again it times out. Do you have a recommendation for at tender that will work in this application. Thank you.

    • Hi. There are many battery tenders that would fit this situation such as the Schumacher and Battery Tender brands, which can be readily found at most automotive and online retailers. Hope that helps!