NOCO GENIUS1 battery charger

The GENIUS1 charges at 1 amp. NOCO rates it to recharge batteries up to 30 Ah and to maintain batteries of any size, so above 30 Ah it works as a maintainer rather than a charger.

Checked against sources on by the TrueAmps editorial team.

NOCO GENIUS1 smart battery charger with clamps
Charge current
1 A
Battery voltages
6 V / 12 V
Recharges batteries up to
30 Ah
Lithium (LiFePO4) mode
Yes
Weight
0.77 lb
Safety listing
UL 1236

Ratings are the manufacturer's own, from NOCO's spec page, checked September 24, 2026. Safety listing: ETL (Intertek), directory record, checked September 24, 2026.

See NOCO GENIUS1 on Amazon

Battery size it is rated to recharge

Largest battery each NOCO charger is rated to recharge. GENIUS1: 30 Ah.GENIUS130 AhGENIUS240 AhGENIUS2D40 AhGENIUS5120 AhGENIUS10230 Ah
Recharge rating from NOCO spec pages. All are rated to maintain batteries of any size.

Charger or maintainer

NOCO's own manual gives the honest picture: a 30 Ah battery at half charge takes about 22.5 hours on the GENIUS1. That is fine for a motorcycle over a weekend. It is slow for a flat car battery.

Where it earns its place is storage. Clip it to a car, bike or boat that sits for weeks and it holds the battery at full. The table below uses NOCO's charge-time ratio for sizes it is rated to recharge.

It works with lead-acid (wet, AGM, gel, EFB, MF, calcium) and lithium LiFePO4 batteries at 6 or 12 volts, per NOCO's spec page.

How long the GENIUS1 takes

Estimated hours from half charged to full, using the charge-time ratio in NOCO's own manuals. How the estimate works.

BatteryFrom 50%From flat
10 Ah7.5 h15 h
20 Ah15 h30 h

Nearest chargers in the range

ModelAmpsUp to AhLithium
NOCO GENIUS1 130Yes
Battery Tender Junior Multi-Chemistry 1-Yes

All battery chargers side by side

Head to head: GENIUS1 vs GENIUS2, GENIUS1 vs Battery Tender Junior

GENIUS1: questions people ask

Can a NOCO GENIUS1 charge a car battery?

NOCO rates the GENIUS1 to recharge batteries up to 30 Ah and to maintain batteries of all sizes. Check the Ah figure on your battery label; above 30 Ah, treat it as a maintainer.

How long does the GENIUS1 take to charge a battery?

NOCO's manual lists about 18 hours for a 24 Ah battery and 22.5 hours for 30 Ah, both from 50 percent charge.

Is the GENIUS1 safety listed?

Yes. It appears in an Intertek directory record for NOCO battery chargers evaluated to UL 1236, checked September 24, 2026.

Check the GENIUS1 listing on Amazon