Charging an AGM battery
An AGM battery needs a charger with an AGM setting. On NOCO's GENIUS5, the AGM mode charges to 14.8 volts, where the standard 12 V mode stops at 14.5, according to its manual.
Checked against sources on by the TrueAmps editorial team.
What the AGM mode changes
The GENIUS5 manual lists one mode for wet, gel, enhanced flooded, maintenance-free and calcium batteries at 14.5 V, and a separate one for AGM at 14.8 V. The lithium mode sits at 14.6 V and, in NOCO's words, is for batteries "with Battery Management Systems (BMS) only" (GENIUS5 user guide). The takeaway: choose the mode that matches the label on your battery.
AGM is printed on the battery label. If you are not sure, the battery maker's charging instructions come first, and the charger manual second.
Chargers that list AGM support
Every charger on this site lists AGM among its supported battery types. Size it the same way as any charger: by the largest battery the maker rates it to recharge.
| Charger | Amps | Recharges up to | Amazon |
|---|---|---|---|
| NOCO GENIUS5 | 5 | 120 Ah | NOCO GENIUS5 on Amazon (paid link) |
| NOCO GENIUS10 | 10 | 230 Ah | NOCO GENIUS10 on Amazon (paid link) |
| NOCO GENIUS2 | 2 | 40 Ah | NOCO GENIUS2 on Amazon (paid link) |
| Battery Tender Junior Multi-Chemistry | 1 | not published | Battery Tender Junior Multi-Chemistry on Amazon (paid link) |
Ratings from each manufacturer's product page, September 24, 2026. Estimate the charge time for your battery.
Questions people ask
Do AGM batteries need a special charger?
They need a charger that supports AGM. On NOCO's GENIUS5 that is a separate 12V AGM mode, which its manual lists at 14.8 volts against 14.5 volts for standard lead-acid.
Can I charge an AGM battery in normal mode?
Follow the battery maker's instructions and the charger manual. NOCO provides a dedicated AGM mode on the GENIUS5, which suggests it treats AGM as its own case.