How many volts is a Lexus RX 350?
In the standard RX 350, the electrical system uses a 12‑volt battery. Hybrid variants, such as the RX 350h, incorporate a high‑voltage battery pack that operates well above 12 volts.
The question spans two versions of the RX 350 lineup. The gasoline RX 350 relies on a conventional 12‑volt electrical system for starting, lighting, and electronics, while the hybrid variants use a separate high‑voltage battery to power the electric motor and assist the gasoline engine. The exact voltages depend on model year and technology, but the 12‑volt system is consistent across the gasoline version, and the hybrid’s high‑voltage pack sits in the low hundreds of volts.
Voltage overview by RX variant
Below is a quick breakdown to distinguish the two main configurations you might encounter:
- Gasoline RX 350: 12‑volt electrical system. The 12V battery powers starting, lighting, and onboard electronics, with the alternator charging it to roughly 13.8–14.4 volts when the engine is running.
- Hybrid RX 350h and related hybrids: High‑voltage battery pack. Nominally around 288 volts, with variations by generation and battery chemistry (NiMH or Li‑ion). This pack supplies the electric motor and works with the vehicle’s inverter; it is separate from the 12‑volt system.
In practice, owners of the gasoline RX 350 interact primarily with the 12‑volt system, while hybrid versions operate a higher‑voltage battery for hybrid propulsion.
Safety, maintenance and measurement
High‑voltage systems require special precautions. Do not attempt to service or measure high‑voltage components yourself if you are not trained. For routine checks like battery voltage, a standard multimeter can verify the 12‑volt system (should read around 12.6–12.8 volts with the car off, and typically 13.8–14.4 volts when charging). If you need precise specifications for a specific model year, consult the owner’s manual or a Lexus service document.
Summary
The RX 350’s gasoline version uses a 12‑volt electrical system, while hybrid variants (like the RX 350h) use a high‑voltage battery pack typically around 288 volts nominal, with some variation by year and chemistry. Always refer to model‑specific documentation for exact figures.
Is 14.7 volts too high on a battery?
A 14.7-volt reading is generally not too high for a 12-volt lead-acid battery while it's being charged, as it's within the typical range for a healthy alternator or charger, though it is at the upper end. However, if the voltage stays at or above 14.7 volts for a prolonged period after the battery is fully charged, or if readings are consistently above 15 volts, it could indicate overcharging and lead to damage.
This video explains the ideal voltage range for a car battery: 1mOBD InsightsYouTube · Feb 13, 2025
What to know about 14.7-volt readings
- While running: A reading of 14.7 volts is common and usually indicates the charging system is working correctly to keep the battery full while the engine is on.
- Maximum limit: Voltages above 15 volts are a strong indicator of overcharging.
- Monitor the voltage: If you see 14.7 volts, monitor the charging process to ensure the voltage drops to a lower, maintenance level once the battery is full.
- Potential for damage: Prolonged overcharging can cause the battery to lose water and shorten its lifespan.
This video demonstrates what a charging voltage too high can look like: 56s1A Auto: Repair Tips & Secrets Only Mechanics KnowYouTube · May 11, 2020
When to be concerned
- If you consistently see a reading above 15 volts.
- If the voltage remains at 14.7 volts for a long time, even after the car has been running for a while.
- If you notice other symptoms of overcharging, such as a glowing check engine light or a rotten egg smell.
If you are concerned about your battery's voltage, it is best to have a professional check the charging system for you.
What kind of battery is in Lexus RX 350?
The Lexus RX 350 typically uses a Group Size 24F battery, but the best way to confirm the exact type is to check the vehicle's specific year and trim, as requirements can vary. You can use an online battery finder or consult your owner's manual for the most accurate match. Common battery options include traditional flooded lead-acid, enhanced flooded battery (EFB), or AGM, all of which should be 12V lead-acid batteries.
Battery types and specifications
- Group Size: Most commonly Group Size 24F.
- Battery Technology: This can vary depending on the model year and options. Popular options include:
- Flooded Lead-Acid: A standard and affordable option.
- Enhanced Flooded Battery (EFB): A more robust option for vehicles with higher power needs.
- Absorbed Glass Mat (AGM): A spill-proof, maintenance-free option.
- Volts: 12VDC.
- Cold Cranking Amps (CCA): The required CCA can vary, but a 750 CCA rating is common for many modern models.
- Terminal Location: Top right front terminal is common for the positive terminal.
How to find the right battery
- Use an online battery finder: Input your vehicle's year, make, model, and engine into a battery retailer's website to see recommended fits.
- Check the existing battery: Look at the label on your current battery for the group size and other specifications.
- Consult your owner's manual: The manual will specify the correct battery type for your vehicle.
How to start Lexus RX 350 with dead battery?
Button. That will start the vehicle with a dead battery you got to hold it right up. There. In this case it starts so we're going to show you what to do in case that starting battery is dead. Next.
How many volts is a Lexus battery?
A fully charged Lexus 12V battery should read approximately 12.6 volts when the engine is off. When the engine is running, the voltage should be higher, typically between 13.7 and 14.7 volts to indicate the charging system is working correctly. If the voltage is below 12.45 volts when the engine is off, the battery is not fully charged and may need to be recharged.
This video explains how to check your Lexus battery and alternator voltage without tools: 1mViktor G AutomotiveYouTube · Aug 30, 2023
When the engine is off
- Fully charged: Around 12.612.612.6 volts.
- Partially discharged: Between 12.412.412.4 and 12.612.612.6 volts.
- Discharged: Below 12.412.412.4 volts, which may require a recharge or replacement.
When the engine is running
- Charging: Between 13.713.713.7 and 14.714.714.7 volts.
- Stable voltage: The voltage should be in this range, with the alternator or generator assembly regulating the output.
This video demonstrates how the 12V battery voltage changes in a Lexus NX: 59sLSFTYouTube · Apr 12, 2024
Other checks
- During cranking: The voltage should not drop by more than about 2 volts. If it drops significantly or below 9.59.59.5 volts, the battery likely needs to be replaced.
- Hybrid battery: The high-voltage hybrid battery has a much higher operating voltage, around 280280280 volts for a Lexus RX450h.
This video explains the voltage of a new high-voltage battery in a Lexus RX450h: 57sEV & Hybrid NetworkYouTube · Apr 10, 2025
