Quick Summary: Comparing 24v car batteries for electric cars involves understanding voltage, capacity (Ah), Cold Cranking Amps (CCA), physical size, and terminal type. Not all electric cars use a 24v battery; most use much higher voltage systems. This guide clarifies what to look for if your EV does use a 24v auxiliary battery, ensuring you choose the right fit for reliable power.

Compare 24v Car Battery for Electric Cars: Your Essential Guide

Buying a car battery can feel a bit confusing, especially with electric cars. You might be wondering about the right voltage, how much power it holds, and what all those numbers mean. If you’re looking into a 24v car battery for an electric vehicle, you’re in the right place. Many electric cars use a 12v auxiliary battery, but some systems might involve or be related to 24v configurations, especially in older or specialized models. We’ll break down what you need to know in simple terms, so you can feel confident about choosing the right battery. No need to worry about complicated jargon here; we’ll keep it straightforward and practical.

This guide will walk you through the essential features of 24v car batteries, help you understand how they work within an electric car’s system, and show you exactly what to look for. We’ll cover everything from capacity to physical fit, ensuring your electric car stays powered up and ready to go. Let’s get started on making this a simple and clear process for you.

Understanding Electric Car Battery Systems

Electric cars are famous for their large, high-voltage battery packs that power the motor. These are often hundreds of volts! But like gasoline cars, many EVs also have a separate, smaller battery. This is usually a 12-volt battery, and its job is crucial. It powers all the accessories you rely on when the main drive battery isn’t active or is being managed: things like your lights, radio, power windows, door locks, dashboard displays, and critical safety systems.

In some electric vehicle designs, particularly older ones or those built on platforms shared with internal combustion engine cars, you might find a system that’s related to or even uses a 24-volt setup for this auxiliary power. This could be achieved by two 12v batteries linked in series, or a single 24v battery. Knowing the specific needs of your electric car is the first step. We’ll focus on the specifications you need to compare if a 24v battery is indeed what your electric vehicle requires.

Why the “24v” Might Be Different in EVs

It’s important to clarify that the massive battery pack driving your EV is not a 24v battery. Those are typically Li-ion and operate at much higher voltages, like 400V or 800V. The 24v term, when discussed in the context of an EV’s “car battery,” usually refers to the smaller, low-voltage (LV) auxiliary battery or batteries that perform the same functions as the 12v battery in a gas car. This LV system is essential for starting up the car’s computers and systems, even before the main high-voltage battery engages.

Sometimes, manufacturers design these systems using two 12v batteries connected in series to achieve 24v. In other cases, a single 24v battery might be used. This distinction is vital. If your electric car manual specifies a 24v requirement for its auxiliary system, you’ll need to find a battery that matches this. Searching for “compare 24v car battery for electric cars” generally implies you’re looking for the correct auxiliary power source, not the main drive battery.

Key Features to Compare for a 24v Car Battery

When you’re comparing 24v car batteries, you need to look at several important specifications. These ensure the battery will work correctly and provide reliable power for your electric car’s auxiliary systems. Think of it like choosing comfortable shoes – they need to fit right and be suitable for the job!

1. Voltage (V)

This is the most straightforward. For a 24v system, you absolutely need a battery ( or combination of batteries that result in 24v) that delivers 24 volts. This is the electrical “pressure.” Using a battery with the wrong voltage can damage your car’s electrical components. If your car uses two 12v batteries in series for a 24v system, ensure both are rated at 12v and have compatible specifications.

2. Capacity (Ampere-Hours – Ah)

Capacity tells you how much energy the battery can store and deliver over time. It’s measured in Ampere-hours (Ah). A higher Ah rating means the battery can power your car’s accessories for longer before needing a recharge. For example, a 100Ah battery can theoretically provide 100 amps for one hour, or 10 amps for ten hours. Your electric car’s manual will specify the recommended Ah range. It’s generally best to stick close to the manufacturer’s recommendation or opt for a slightly higher Ah for better longevity, but don’t go drastically higher as it might not fit or charge correctly.

3. Cold Cranking Amps (CCA)

CCA is a rating that indicates how much power a battery can deliver for starting an engine in cold temperatures. While electric cars don’t “crank” an internal combustion engine, the accessory systems still need a strong electrical surge to power up the complex electronics and computers when you “start” the car. A higher CCA rating means the battery is more robust and can handle sudden power demands better, especially in cooler weather. Even for an EV’s auxiliary battery, a decent CCA rating (often around 500-700 CCA for many systems) can be important for reliable power-up.

4. Physical Size and Terminal Type

This is critical for a proper fit. Batteries come in various sizes, often referred to by group numbers (like Group 65, Group 34, etc.). You need to measure the space where the battery will sit in your electric car and compare those dimensions (Length, Width, Height) to the battery specifications. Also, check the terminal type and placement. Most car batteries have top posts, but some might use side posts or different configurations. Ensure the terminals on the new battery can connect securely and correctly to your car’s cables.

5. Battery Chemistry

While traditional gasoline cars often use flooded lead-acid batteries, electric cars might utilize different technologies even for their auxiliary batteries, such as Absorbed Glass Mat (AGM) or even Lithium-ion. AGM batteries are generally preferred for modern vehicles because they are more durable, resistant to vibration, and sealed, meaning they don’t leak acid and require no maintenance. Always check what type of battery your EV manufacturer recommends.

Comparing Specific 24v Battery Models for EVs

When you start looking at actual battery models, it’s helpful to compare them side-by-side. Since the market for specifically 24v auxiliary batteries for electric cars is less common than 12v, you’ll often be looking at high-quality 12v AGM batteries meant to be used in pairs, or potentially specialized 24v units if available for your specific EV make and model. Always consult your vehicle’s owner’s manual first to confirm the exact requirements.

Table: Example Comparison of High-Quality AGM Batteries (Often used in Pairs for 24v Systems)

This table shows how you might compare two types of high-quality AGM batteries that could form part of a 24v system. Remember, for a 24v system you’d likely buy two of the same 12v battery.

Factors Beyond Specs

Beyond the numbers, consider:

• Brand Reputation: Stick with well-known, reputable brands. They often have better quality control and customer support.
• Warranty: A longer warranty (3-5 years is common for good AGMs) indicates the manufacturer’s confidence in their product.
• Reviews: See what other owners of your specific electric car model say about the batteries they’ve chosen.
• Availability: Can you easily find this battery when you need a replacement?

Installation: Safety First!

Replacing a car battery, even an auxiliary one, requires careful attention to safety. If you’re not comfortable with working on your car’s electrical system, it’s always best to have a professional do it. Here are the general steps and critical safety precautions:

Essential Safety Gear:

• Safety glasses or goggles
• Insulated gloves
• Protective clothing (avoid loose items)
• A clean rag or shop towels

Tools You Might Need:

• Wrench set or socket set (common sizes are 10mm, 13mm)
• Battery terminal cleaner brush
• Anti-corrosion spray or grease
• A memory saver (plugs into the OBD-II port to maintain vehicle settings) – optional but recommended for EVs.
• Safety glasses

Step-by-Step Installation Process (General for Auxiliary Battery):

1. Park Safely: Ensure your electric car is parked on a level surface, turned off, and the parking brake is engaged.
2. Locate the Battery: In many EVs, the auxiliary battery is in the trunk, under a seat, or in the engine bay, often in a slightly less obvious spot than in a gas car. Consult your owner’s manual.
3. Disconnect the Negative Terminal First: This is crucial! Identify the negative (-) terminal (usually marked with a black cover or symbol). Using your wrench, loosen the nut on the terminal clamp and carefully lift the negative cable off the post. Move it aside so it cannot accidentally touch the battery terminal. Always disconnect the negative first to avoid short circuits.
4. Disconnect the Positive Terminal: Now, identify and disconnect the positive (+) terminal (usually marked with a red cover or symbol). Loosen the clamp and remove the cable.
5. Remove the Battery Hold-Down: Batteries are secured with clamps or brackets. Unscrew and remove these.
6. Lift Out the Old Battery: Batteries are heavy! Use proper lifting techniques or get help if needed. Be careful not to damage anything around the battery tray.
7. Clean the Battery Tray and Terminals: Use a wire brush to clean any corrosion from the battery tray and the cable clamps.
8. Place the New Battery: Carefully set the new battery into the tray, ensuring it sits flat and secure. Make sure it’s oriented correctly so the positive and negative terminals align with the corresponding cables.
9. Secure the Battery: Reinstall the hold-down bracket and tighten it firmly. The battery should not move at all.
10. Connect the Positive Terminal First: Now, connect the positive (+) cable to the positive terminal post and tighten the clamp.
11. Connect the Negative Terminal Last: Connect the negative (-) cable to the negative terminal post and tighten the clamp. Connecting the negative last is essential for safety.
12. Apply Anti-Corrosion: You can apply a thin layer of dielectric grease or anti-corrosion spray to the terminals to prevent future corrosion.
13. Check Everything: Double-check that all connections are tight and the battery is secure.
14. Start Up: Turn on your electric car to ensure all systems function correctly. You may need to re-enter radio presets or other settings if you didn’t use a memory saver.

If your electric car uses two 12v batteries in series for a 24v system, you will repeat the process for both batteries, ensuring they are connected correctly with a jumper cable between them. Verify the series connection is standard for your vehicle. A great resource for general car battery maintenance (which applies to auxiliary batteries) can be found on government sites detailing vehicle care, such as resources from the U.S. Department of Energy on electric and hybrid vehicles, though specific auxiliary battery information can be found within a vehicle’s manual. Always refer to your specific electric car’s repair manual for the most accurate, model-specific guidance.

Common Issues and Troubleshooting

Even with the best battery, issues can arise. Here’s what to watch out for:

• Car Won’t Turn On (No Power at All): This is a classic sign of a dead or disconnected auxiliary battery. Check connections first. If they’re good, the battery itself might be the culprit.
• Warning Lights on Dashboard: A weak or failing auxiliary battery can cause various electronic glitches, including dashboard warning lights related to the electrical system or battery.
• Slow Power Windows, Dim Lights: These are indicators that the accessory power is struggling, often pointing to an aging auxiliary battery.
• Corroded Terminals: Green or white powdery buildup on the battery terminals can impede electrical flow. It’s a sign that the battery might be leaking, or just needs cleaning.
• Battery Not Holding Charge: If your car starts fine but the battery drains quickly after being turned off, it likely needs replacement.

Important Note for EVs: Because EVs manage their main battery systems very differently, a faulty auxiliary battery can sometimes trigger unusual errors or prevent the main drive system from engaging. Always consider the auxiliary battery as a potential source of problems if your EV exhibits strange electrical behavior.

Battery Disposal and Recycling

Car batteries, including auxiliary batteries in EVs, contain hazardous materials like lead and acid. It’s crucial to dispose of them responsibly. Most places that sell car batteries will accept your old one for recycling when you purchase a new one. Many auto parts stores and recycling centers also offer free battery drop-off. Never throw a car battery in the regular trash. Recycling is not only good for the environment but is often a requirement by law.

Frequently Asked Questions (FAQ)

Q1: Do all electric cars have a 24v auxiliary battery?

No, not all electric cars use a 24v auxiliary battery. Many use a standard 12v auxiliary battery, just like gasoline cars. Some might use two 12v batteries connected in series to create a 24v system. Always check your car’s owner’s manual to confirm the specific battery type and voltage required for its auxiliary system.

Q2: Can I use a 12v battery if my EV needs a 24v system?

No, you cannot. If your electric car is designed for a 24v auxiliary power system (whether it’s a single 24v battery or two 12v batteries in series), you must use a battery or batteries that provide 24v. Using a 12v battery will not provide enough power and can cause your car’s systems to malfunction or not start at all.

Q3: How often should I replace my electric car’s auxiliary battery?

Auxiliary batteries, even in EVs, typically last between 3 to 5 years. However, this can vary based on climate, battery quality, and usage patterns. It’s a good idea to have your auxiliary battery tested during your regular vehicle maintenance checks, especially as it approaches the 3-year mark.

Q4: What is the difference between a 24v car battery and the main EV battery?

The main EV battery is a high-voltage (often 400V or higher) lithium-ion battery pack that powers the electric motor for driving. The 24v (or 12v) “car battery” is a low-voltage auxiliary battery that powers the car’s accessories like lights, infotainment, power windows, and the onboard computer systems that manage everything. They serve entirely different purposes.

Q5: Can I upgrade my 24v auxiliary battery to a higher Ah rating?

In general, you can opt for a slightly higher Ampere-hour (Ah) rating if it fits physically and is the correct voltage and type. A higher Ah battery can provide power for longer. However, don’t go too high, as it might overwhelm the charging system or not fit the battery tray. It’s best to stick within the manufacturer’s recommended range