NOCO Genius 1

It ranks #2 (A tier) on our consolidated car battery chargers board, drawn from 6 independent outlets.

Limited amperage. No smart-charging features.

Someone who wants a small, simple maintainer to keep a car, motorcycle or boat battery topped up while it sits. Its compact size and ease of use earned it second place on our car battery chargers board, and reviewers praised a robust build and a three-year parts and labour warranty. Its limits are a 1-amp output and no smart-charging features, so if you need to recharge flat batteries rather than maintain charged ones, pick the CTEK MXS 5.0 at the top of the board, or the NOCO Genius 10 for large batteries.

Our research recorded robust construction that withstands long-term use, and NOCO backs it with a three-year warranty covering parts and labour. A maintainer spends most of its life at very low current, which is an easy duty. Keep the clamps clean and the unit dry and it should outlast the warranty by years.

It can, but slowly. At 1 amp a flat 60 amp hour car battery needs well over two days to reach full, so the NOCO Genius 1 is best treated as a maintainer that keeps a charged battery full. For recovering flat batteries the CTEK MXS 5.0 charges about five times faster.

Roughly one amp hour of capacity per hour, plus about a fifth for losses. A small motorcycle battery that is half flat takes about ten hours, and a car battery takes more than a day. Connected to a battery that is already charged it simply holds it there, which is the job it is built for.

Yes, that is its purpose. Once the battery is full it holds the charge at a low current rather than overcharging, so it can stay connected for months of storage. Mount it off the floor, keep it away from water and connect the black clamp to bare metal on the chassis.