If you drive your car regularly, it’s unlikely you will encounter a completely flat battery, but as car batteries age, they struggle to hold a charge. To keep your car battery juiced, you can use a maintainer/charger. Some of the products in this top five roundup even extend the life of your car battery. Add in the convenience of a portable-size unit, and you have the most proactive solution for a wonky car battery.
Black and Decker BC2WBD 2 Amp Waterproof Battery Charger / Maintainer
- Capacity — 2 or 6 Amps
- Outputs — 3 ports (battery clamps, rings, and 12-volt)
- Weight — 1.7 pounds
- Price — $30
What good is a portable battery charger if it’s ungainly? Believe it or not, but there are “portable” car battery chargers on the market that weigh almost 30 pounds and need to be wheeled around. Unless you’re running a vehicle fleet, something more along the lines of this Black + Decker 2 Amp charger will suit your needs.
Weighing just 1.7 pounds and measuring just 9.1 x 5.3 x 3.5 inches, this tiny power unit can easily fit in a trunk and may even fit in your car’s glove box. The charger is also waterproof and is sealed to protect it from dust and moisture, making it ideal for travel. Both two- and six-amp versions are available — both costing less than $35.
Stanley BC25BS Bench Battery Charger
- Capacity — 15 or 25 Amps
- Outputs — 2 ports (battery clamps and 12-volt)
- Weight — 8 ounces
- Price — $79
Looking for a bit more versatility and durability? Check out the Stanley Bench Charger. With fast, high-frequency technology, it delivers three-stage charging and will automatically switch between modes: fast charge, top-off, and trickle charge. You can set and forget the charger, or you can monitor charging and battery status on a digital LCD screen.
The Stanley Bench Charger also features an alternator check to evaluate battery voltage under load, indicating whether the alternator is maintaining battery level. Considering a bad alternator is the next most common culprit for a car refusing to start, this is a really nifty feature. Last but not least, the charger can also jump-start your car if the battery refuses to charge or if you need to get on the road in a hurry. Sure it isn’t crazy cheap, but the bench charger is full of useful functions.
Sunway Solar Car Battery Charger
- Capacity — 2 Amps
- Outputs — 1 port (12V)
- Weight — 1.5 pounds
- Price — $38
For maximum efficiency, consider a solar-powered charger like this one from Sunway Solar. While this might not be the most robust portable car battery charger, it is convenient and tackles some of the biggest causes of battery drain: Car alarm systems, engine computers, and (for you forgetful folks), headlights left on. Consider this your eco-friendly battery maintainer.
Just mount the solar charger on one of your car’s windows or stick it on the dashboard, plug it into your 12V port, and you are good to go. Features include weatherproof, ultra clear PV glass, a durable ABS plastic housing, and an LED indicator for when the system is charging. Wield the power of the sun, people!
Schumacher SEM-1562A-CA 1.5 Amp Speed Charge Battery Maintainer
- Capacity — 1.5 Amps
- Outputs — 3 ports (battery clamps, rings, and WM-12 connector)
- Weight — 1.4 pounds
- Price — $30
Like the Black and Decker charger, this Schumacher unit is light (1.4 pounds) and compact (7 x 7.5 x 11 inches) for easy portability. The Speed Charge can refuel and maintain six- and 12-volt batteries through a number of different ports, including battery cables, rings, and a WM-12 connector. Distinguishing the Schumacher unit from competitors is an automatic mode that switches between charge and float mode to avoid overcharging the battery.
The Speed Charge also features reverse polarity protection to extend the charger’s life and a one-year manufacturer warranty. Putting out just 1.5 Amps, it would take the Speed Charge a good long while to restore a car battery, so it’s best to use this as a battery maintainer.
Schumacher SE-5212A 2/10/50 Amp Automatic Handheld Battery Charger
- Capacity — 50 Amps
- Outputs — 1 ports (battery clamps)
- Weight — 10.5 pounds
- Price — $65
By far the most potent portable car battery charger in this roundup, the Schumacher Automatic Charger puts out double the maximum amps of the Stanley Bench Charger. There is a bit of a weight penalty for all this power (the Schumacher unit is a hefty 10.5 pounds), but it can also completely restore a battery in less than five hours.
In addition to being able to charge 12-volt batteries, the Automatic Charger puts out three different levels of power: 2- to 6-ampere charge/maintain, 10-ampere boost, and 50-ampere engine start (yes, this unit can jump-start your car). Schumacher says its charger won’t overcharge your car’s battery and it can even lengthen your battery’s life. So, the question is: Do you want a featherweight system or one that can jump-start a planet?
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