When to Use a Battery 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 maintainers can keep any car battery charged at all times. Here’s how battery maintainers work.
Battery Maintainer vs Battery Charger
A lot of people aren’t sure what makes a battery maintainer — 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 maintainer 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 maintainer won’t overcharge the battery like a charger might, which can help extend the life of the battery overall.
The Best Time to Use a Battery Maintainer
Clearly, the main advantage of battery maintainers 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 maintainer 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.
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 than the tender can keep it up – due to battery failure or something overly draining it, this will not help. Perhaps further tests conducted by a certified mechanic may be useful to see what is actually causing this issue may be the next best step.
Usually, a parasitic draw can be located by connecting an ammeter to the battery, then removing one fuse at a time to see if the draw stops when a certain fuse is pulled.
Any auto/electric shop can trouble-shoot your problem.
my car is parked outside and most of the time here in winnipeg canada the temp is as low as -30C will a battery maintainer 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 firstname.lastname@example.org.
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 maintainer 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.
We have a 2008 335i BMW. Battery was several years old and car isn’t driven much. The clock & radio started losing settings so I started using a Trickle Maintainer for about a year now. Finally replaced the battery yesterday. No issues with resetting the computer. Thanks.
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.
Take pos cable off before you leave
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 maintainers that would fit this situation such as the Schumacher brand, which can be readily found at most automotive and online retailers. Hope that helps!
Check your vanity mirror lights
“A lot of people aren’t sure what makes a battery maintainer — which is also called a battery maintainer — ”
Oh, good to know.
Big difference Richard, I have a C4 , and where I store my Corvette, there is no running electricity. I currently live in Illinois, hoping to change that soon, but the winters get really cold as you know, Would my best bet be to take the battery out of my car, and hook it up to a maintainer ? Thank you
You send this to EverStart, Their customer service could not answer my question as to if it was ok to leave their BC3E maintainer on for long periods of time
I have a C4 and where I store it, there is no running power source. Should I take the battery out of the Corvette once it is fully charged, and hook it up to a battery maintainer ? Thank you
What is the difference between a maintainer, tender & trickle charger. I am lead to believe that for my RV, which will be in storage for 5 months should have a tender and not a trickle charger on its chassis battery (?) Is a maintainer a tender charger ( interchangeable name)?
Hello I have a 1999 Corvette which I store for winter Dec-Mar in my unheated NH garage. I have used battery maintainers like Battery Tender & Schumacher for years. I have a 6 year old DieHard AGM which may have bad cell, I noticed red “bad battery” light on most days. My question, as we are in middle of winter now, could I leave maintainer hooked up till better weather to replace battery? Is there any harm or advantage leaving it hooked up 2 more months?
Excellent article. Learned all I need to know about a battery maintainer. Thanks.