REFERENCE 25-00 · BATTERIES & ENERGY STORAGE
Battery Charging Voltage Chart
Reference charging voltages for 12V nominal lead-acid (flooded/AGM) and LiFePO4 battery banks. Charging the wrong chemistry with the wrong profile is one of the most common causes of premature battery failure we see in the field.
Flooded & AGM Lead-Acid (12V Nominal)
| Stage | Voltage |
|---|---|
| Bulk / Absorption | 14.4–14.8V |
| Float | 13.2–13.8V |
Temperature compensation matters: lead-acid charging voltage should shift by about 0.0167V per °F for a 12V battery (6 cells × 0.0028V per cell per °F, or 0.005V per cell per °C). Lower it as the battery gets warmer than 77°F (25°C) and raise it as it gets colder. That is Trojan’s published figure; follow your battery maker’s number if it differs. Most quality converters/chargers with a remote battery temp sensor (BTS) handle this automatically — without one, a charger can overcharge in summer heat or undercharge in cold.
LiFePO4 (12V Nominal)
| Stage | Voltage |
|---|---|
| Bulk / Absorption | 14.2–14.4V (never above 14.6V) |
| Float | ~13.5V (many packs don’t require float at all) |
These figures reflect common defaults from Victron and Epoch (Epoch publishes 14.2–14.4V bulk/absorption, float off or 13.3–13.6V, 13.2V re-bulk and a 14.6V maximum; Epoch charging specs) — always confirm against your specific battery/BMS manufacturer’s published settings, since LiFePO4 charge profiles vary more between brands than lead-acid does. Do not apply lead-acid-style temperature compensation to LiFePO4. Instead, respect the BMS’s low-temperature charge cutoff — charging LiFePO4 below ~32°F (0°C) causes lithium plating and permanent capacity loss, even though most BMS units will block it automatically.
Never Mix Charge Profiles
A converter or inverter/charger set for lead-acid absorption/float behavior will chronically undercharge a LiFePO4 bank (never reaching full capacity) or, on some older non-adjustable units, can fail to properly terminate the charge cycle. Confirm your charger has a dedicated, adjustable lithium profile — or a BMS that can safely accept a lead-acid-style charge curve — before switching chemistries in an existing rig.
Related Reference Pages
Wire Ampacity & Voltage-Drop Chart
Electrical & Power Systems
LiFePO4 Battery Buying Guide
Full Field Guide
⚠ Safety note: This page is for informational purposes only and is not a substitute for the advice of a qualified professional. Incorrect charging voltages can damage batteries, void warranties, or in rare failure conditions create fire risk. Always verify settings against your specific battery and charger manufacturer’s current documentation. United Mobile RV LLC is not responsible for outcomes of DIY work performed using this reference. Rev. 1 — August 2026.
OUR TOOL KIT
Battery testing gear
Victron SmartShunt battery monitor — Shows what each appliance actually draws, in amps, on your phone.
Fluke 117 True-RMS multimeter — The meter we use for 12V and 120V diagnosis.
NOCO GENIUS10 smart charger/maintainer — Keeps the house or chassis battery topped up in storage or between trips, including lithium.
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