Can You Leave A Trickle Charger On All The Time?

A trickle charger is an essential tool for car owners that helps prevent their vehicle batteries from completely draining. But have you ever wondered if you can keep your trickle charger on all the time? Don't worry, we thought of the same thing, that is why we have scoured the internet and asked the experts this exact question. Read below to find out the answer. 

The length of how long you can keep a trickle charger on depends heavily from brand to brand. Some trickle chargers will allow you to leave them overnight, while some up to 48 hours. Leaving electrical units like this unattended could also pose a potential fire hazard if they short circuit. 

For more information please continue reading as we will tackle other related questions such as the length of trickle charging, what is a trickle charger, and the effects of trickle charging on your car's battery life. We will also be linking some exciting topics at the end of this article for you to read. So go ahead and finish reading. 

Car battery under the hood, Can You Leave A Trickle Charger On All The Time?

Can you leave your trickle charger constantly plugged in?

Leaving any electronic appliance plugged in or running all the time could cause potential damage to the unit itself. With trickle chargers, the higher the amp, the shorter time it needs to be on, while a lower amp charger may take days

It pays to know what kind of trickle charger you have and the limits of the charger. An electronic can likely experience short-circuiting, especially if it is already experiencing an overload. A short circuit happens when your electrical wire starts to heat up due to too much electricity passing.

Short circuits are potential hazards that can either electrocute you or cause a fire. This can be a huge concern, especially if children or older people are in your house. 

Aside from safety concerns, a trickle charger that is always running also contributes to unnecessary electrical consumption, which can, in turn, add more cost to your monthly electric bill. 

What is a trickle charger?

A trickle charger is a device that prevents your car's battery from losing charge to keep it working. It charges the vehicle battery through low-voltage. This design improves and preserves the battery's health —more on this topic below. 


While the car is running, your alternator is responsible for keeping your battery at full charge. If your mobile's battery experiences a heavy discharge, an alternator might have difficulty recharging it. 

When choosing your trickle charger, it is best to remember that not all car batteries are compatible with all chargers. There are three types of car batteries. AGM [Absorbent Glass Mat], EFB [Enhanced Flooded Batteries], and SLI [Starting, Lighting, Ignition].

It is usually indicated what kind of battery is compatible with the charger. But there are universal trickle chargers available in the market that can charge all three types. 

Click here to see universal trickle chargers on Amazon.


How long does it take to charge a battery with a trickle charger fully?

The car mechanic is using a voltage measuring instrument and charging the battery

Determining how long a car battery will be charging depends on how drained the battery is and how strong the trickle charger is. A completely dead battery charged in a one amp trickle charger may take two days. If it is plugged in using a two amp charger, the charger can fully charge the battery within 24 hours.

Sometimes you can mistakenly identify a battery that already needs replacing with an only drained one. A car battery may last you roughly 3-4 years on average. 

But multiple factors can affect your car's battery. If it is often drained for whatever reason [be it with a faulty alternator or you just forgot to turn off your vehicle without the engine running], draining can shorten the battery's life span. 

Signs that car battery needs replacing

Car repaid garage technician checks lifespan of a car batery with a multimeter

A battery that needs replacing may take longer to charge, even with a more robust amp. It may also quickly discharge even while connected to a properly functioning alternator. Below are some telltale signs that your vehicle's battery has surpassed its life cycle. 

Electronics malfunctioning

One of the most common symptoms you can quickly notice when your car battery fails is malfunctioning electronic parts. Some indications may include power windows not responding, cabin lights flickering has weakened, windshield wipers not working, sunroof unresponsive, and other car electronic components.

Difficulty in start-up

The car battery is responsible for activating converted electrical energy and delivering it to your car's starter, which cranks the engine for the start-up. When starting the vehicle; if your battery already needs replacement, you may experience some difficulty starting up your automobile; it may crank but won't turn.  

Warning Light

If your battery is depleted or running low on power in some cars, a warning light pops out of your dashboard display. Also, a warning light may indicate a problem with your battery. 

Weakened lights

Macro view of modern blue car xenon lamp headlight

Another symptom of a defective battery is flickering and dimming of your headlights and taillights, including your brake lights. It could be a potential safety hazard while driving at night. Weak lights may make your visibility and your visibility to other drivers challenging. This is especially true during rain and snow. 


Corrosion can come from a battery leaking fluid out of it. A physical check by popping up your hood can tell you if you are experiencing this. It could mean that your battery is already due for replacing, as the fluid from your battery is acidic and can cause further damage to other parts of your car if untreated. 

Coroded car battery

What is the effect of trickle charging on your battery life. 

There has been a long belief that trickle charging helps prolong your battery's life. While actually, the benefits of trickle charging to the overall health of your battery are just marginal gains.

But whether it be marginal or not, gains are gains. Some would argue that they would accept any help in improving and prolonging the length of how long you can utilize your vehicle's battery. Therefore, a trickle charger has positive effects on battery health.

One drawback with some trickle chargers is the lack of indicators if the battery is already fully charged or not. If you are not sure how much charge is left on your battery, you may tend to overcharge or undercharge it.

If your charger is equipped with high-end technology that utilizes microprocessors, it will usually have a battery indicator. With this, you can prevent under and overcharging of your battery. Of course, this type of trickle charger would be more expensive than regular ones. 

Another advantage of newer chargers is they automatically stop charging your battery once it is complete. While on the other hand, older and non-smart chargers would require you to unplug them once your battery gets full. 

This regulating feature makes smart chargers better, as this eliminates the chance of overcharging your battery. These regulators also assist in dampening the effects of power fluctuations if ever the charger experiences a sudden surge of electricity from a faulty power supply.

Electrolysis is the primary nemesis of overcharging your battery; this happens when electric currents pass through circuits. In overcharging, the repeated passing of currents can cause a chemical change in the battery, affecting its cycle. This is mitigated with a trickle charger as only small amounts of amps are used to charge the battery. 

Is it OK to leave Battery Tender on all the time?

Yes, you can leave battery tenders on for a very long time, as they are designed to be used this way. Battery tenders are used when storing your vehicle, boat, bike, etc., for a certain period.

These are small chargers that charge your battery with amps to avoid running out of power while in stock. Like trickle chargers, they also help in extending and preventing damage to your vehicle's battery. 

There are multiple types of battery tenders; some tenders draw power conventionally from a wall socket, while some use solar energy through a solar panel

But even though some battery tenders can be turned on for long periods, we should still be cautious, especially if you have to plug it. That is why a solar one can be more advantageous as it is cost-efficient when it comes to your electric bills and is safer. However, a drawback of this is that they are more expensive than non-solar ones. 

In review

Leaving your trickle charger always running can cause multiple hazards in our garage or workplace. It is wise to only power it on when charging a car battery, as this is more cost-efficient in power consumption. This is also another safety practice as electrical appliances should not be left unattended for a long time. 

Furthermore, there are multiple battery types, which require a specific kind of trickle charger. Still, universal chargers are available if you only want to own one charger while juicing up different car battery types. And as always, safety should be our number one concern. 

Here are some related articles we have previously written for you. Go ahead and check them out!

How Long Can A Deep Cycle Battery Last Without Charging

Do RV Batteries Charge When Plugged Into Shore Power?

How Long Can A Car Battery Last Without The Engine On?

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One comment

  1. hi i bought a new interstate battery sealed batt-and bought a deltran 500 ma trickle charger maintainer- this is for my 1990 corvette as with all the drains from equipment that stays on all the time in the car that will drain the battery- the deltran said it can be left on all the time to keep the battery charged up as i don’t use it as a daily driver and 17000 miles on the car now- any advice would be great at this point-thanks Ronald

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