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Few Canadian drivers ever thought of needing a battery maintainer just a few years back, but with the multitude of electronics and computer modules packed into today’s vehicles, all drawing power to some extent with the ignition off, and the practise of some owners parking their rides for days at a time for whatever reasons, these little devices for traditional 12V batteries have seen a surge in popularity.

What Is a Battery Maintainer?

Unlike a traditional battery charger, a car battery maintainer is considerably more compact and operate on much lower amperage rates. They’re not designed to fast charge car batteries or provide boosting power to a discharged battery but as their name suggests they maintain a battery’s state of charge.

They are definitely not the same as trickle-chargers which must be regularly and frequently checked when in use to prevent overcharging.

Types of Battery Maintainers

Different types of batteries such as lead-acid, AGM, and gel have different requirements for their maintainers. You need to know which type your vehicle has and to check if the maintainer you’re considering is compatible. This information is often printed on the top side of the battery, but if not, check with an authorized dealership to find out. There are maintainers on the market that also have charging and boosting capabilities. These can come in handy if you have other electric start equipment that might need starting help from time to time such as snow blowers, mowers, ATVs and such. But those dual-feature units are usually considerably larger than the pocket-sized maintainers and that difference is important as we’ll find out.

Your car’s battery will determine the kind of maintainer you buy.Photo by Amazon

Features to Look for When Buying a Battery Maintainer

A maintainer is not a plug it in and forget it unit unless it has the capability of detecting a full battery charge and then shutting off the power to the battery when that state is reached. Most maintainers have this feature, but check the label.

A maintainer that doesn’t automatically power down when the battery is fully charged can overcharge and permanently damage the car battery as well as creating a fire risk. Getting a unit with a display on charge rates and polarity confirmation is also helpful.

How to Use a Battery Maintainer

Follow the maintainer’s instructions for proper use. It will involve connecting the unit’s clamps to the battery’s terminals or posts and then plugging in the maintainer to a household 120v outlet, in that order, to avoid any sparks. This means knowing which post is positive and which one is negative. Positives are usually marked with a plus sign on the battery top and have a red coloured cable attached while negatives have a minus sign and are attached to a black cable. The connection has to be solid and metal to metal, meaning cleaning off any corrosion on the battery posts and cable ends and twisting and scraping the teeth of the maintainers’ clamps on the cable ends to scrape down to clean metal.

If your battery is hidden away in a fender well or under-floor location in the trunk or passenger area, find and use the booster jump posts installed under the hood by the automaker. You may have to refer to the owner’s manual if these aren’t clearly marked. Some drivers will permanently mount a car battery maintainer under the hood thanks to their compact size and connect it to the battery with cable eyelets; this should only be a job for an experienced DIYer or a professional tech. With this set up, the 120v power cord can be routed the same as block heater cord for easy and repeated access.

As there is always the risk of venting explosive gases when providing external power to a battery, the area where they are being used should be well ventilated such as an outdoor parking spot or an open ended carport.

How much do car battery maintainers cost?

Expect to spend anywhere between CDN $20 to CDN $80 for a maintainer, depending on the brand and features.

Battery maintainer connected to car's battery
If it has the capability to ‘switch off’, you can leave the battery maintainer connected to the car’s battery without worrying about overcharging.Photo by Getty

Battery Maintainer Vs Charger

Maintainers are not designed for quick charging like a purpose built charger/booster. They may bring a discharged battery back to life if there’s no internal problem with the battery, but it may take hours or days to reach a full charge.

Using a Battery Maintainer during winters

Maintainers are safe to use in colder weather, but they can take longer to do their job if the vehicle is parked outside. But if they’re left plugged in during vehicle downtime this usually doesn’t present any problems.

FAQs

  • Can a battery maintainer recharge a dead battery?

Yes, depending on the health of the battery, and the amount of time you have to spare. If short on time, you can jump start your car instead.

  • Is it okay to leave a battery maintainer on all the time?

Yes if it’s equipped with an auto-off feature.

  • Should I disconnect battery when using a battery maintainer?

No, thanks to the low power flow from the maintainer to the battery, there’s very little risk of damaging the vehicle’s wiring or other components.

  • Do battery maintainers shorten battery life?

No, quite the opposite. Regular maintainer users report extended battery life thanks to the lack of extreme charge and discharge rates when using these devices.

  • Can a battery maintainer overcharge a battery?

No, if they’re equipped with an auto-off feature as most are.

  • Can you start your car with a battery maintainer connected?

If its 120v power source is disconnected there is no risk of damaging the maintainer when starting a vehicle that it’s hooked to. Battery maintainers are available from all auto parts stores and Canadian Tire and start at around $50; a smart and cheaper alternative to waiting for roadside service and being delayed in getting going.

If you’re looking to purchase the best battery maintainer, we have a small selection of top rated ones available online.

Top Rated Battery Maintainers on Amazon

Noco Genius1

Price: CDN $60.79

The battery maintainer has 50,119 ratings online and an average score of 4.6 out of 5. The manufacturer calls it an all-in-one device with battery maintainer, charger and trickle charger built in.

Where to buy:Amazon

Noco Genius 1

Motopower MP00205A

Price: CDN $25

This battery maintainer has 10,888 ratings in total and an average star rating of 4.6 out of 5. The manufacturer claims that the unit can maintain nearly all types of batteries for cars, motorcycles and RVs.

Where to buy:Amazon

Motopower MP00205A

Top Rated Battery Maintainer on Walmart

Everstart BM1E

Price: CDN $29.88

This model has 600 consumer ratings with an average score of 4.2 out of 5. The manufacturer claims that the unit is fully automatic and is built using lightweight polymer plastic.

Where to buy:Walmart

Everstart BM1E

Top Rated Battery Maintainer on Canadian Tire

Noco Genius2

Price: CDN $69.99

This product has 227 ratings online and an average score of 4.6 out of 5. The unit can be used on 12V and 6V batteries. Manufacturer also claims that the product can also power up dead batteries.

Where to buy:Canadian Tire

Noco Genius2

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