The best car battery chargers

A built-in thermal sensor adjusts the charge to a cold garage, five amps brings a run-down car battery back, and it can then stay connected all winter. It takes 6V and 12V, lead-acid and lithium (LiFePO4), so the car, a 6V classic and a lithium motorcycle battery are all covered. CTEK’s MXS 5.0, which owners rate higher, costs more and takes 12V lead-acid batteries only.

What owners say: Hooking it up is simple and the rest is automatic, by owners’ accounts, and it keeps batteries healthy; one has brought more than one dead battery back to life with it. Its small size, solid build and modes for every kind of battery all win praise.

• Wall bracket and screws included
• Reaches a car parked nose-in
• 3-year warranty

Built to be left on: it checks the battery, charges it in eight steps and holds it at full for as long as it’s connected, adjusting to the temperature, so a car can sit on it from November to April. It has an IP65 case and a five-year warranty, and CTEK began in 1997 in Vikmanshyttan, a Swedish village.

What owners say: Simple to use and at home on all sorts of vehicles, owners say, bringing batteries back to full and keeping them there; one is still going strong after eight years, and the reconditioning mode earns praise for reviving older batteries.

• 8-step automatic charging
• Small-battery program for motorcycles
• Dustproof, water-resistant case
• 5-year warranty
• Clamps and eyelets included

The GENIUS5’s smaller sibling: 2 amps for 6V and 12V batteries, lead-acid or lithium. NOCO designs it for batteries up to 40Ah, the size in most motorcycles, mowers and ATVs, and says it will maintain bigger ones, so it also suits a car that sits for weeks.

What owners say: Small enough to leave under the hood, owners say, with instructions that are easy to follow; it keeps batteries in good health and copes with lithium as well as lead-acid, and one credits it with reviving a completely dead battery. One finds it too slow for bigger batteries.

• Mounting bracket in the box
• LED status indicators
• 3-year warranty

Fifteen amps at 12 volts brings a big truck, RV or boat battery back from low far sooner than a maintainer can, and it charges 24-volt batteries too, at 8 amps. Nine stages end in a float charge that can run all winter, and it compensates for the temperature, with a winter mode for the cold months.

What owners say: Owners say it does the job reliably and feels solid and well made, and they like the charging speed, the choice of modes and the charge reading on the screen; opinions on its power vary.

Heads up: It’s a charger, not a jump starter, and NEXPEAK says it can’t bring back a battery that has dropped to 0 volts.

• Colour screen shows charge %
• 9-stage charging
• 2 m (6.7 ft) cord
• Built-in cooling system
• 2-year warranty

A pocket-sized 12-volt maintainer for a motorcycle, a summer car or a lawn tractor parked until spring. At 800 milliamps it charges a motorcycle battery of up to 30Ah and, slowly, a car battery of up to 80Ah, then holds it on a steady float so it doesn’t run down over the winter.

What owners say: Clip it on and forget it, owners say: it’s small, keeps batteries charged and, as one notes, never overcharges. Some call it dependable, while others had one stop working after about a year.

Heads up: MOTOPOWER rates it for indoor use only, from −20°C to 50°C, so run it in a garage or shed rather than out on the driveway.

• Ring terminals stay bolted on
• Won’t overcharge, 24-hour timer
• Spark-free, reverse-polarity safe
• Pocket-sized
• Alligator clips also included