RV Battery Not Charging When Plugged In? With Troubleshooting

Owning an RV is all about the freedom to explore and roam, but a vital component of this nomadic lifestyle is a fully functional battery. When your RV battery isn't charging when plugged in, it can throw a wrench into your travel plans.

In this article, we'll delve into the common causes of this issue and provide practical solutions to ensure you get back on the road with a fully charged battery.

How Do RV Batteries Work?

RV deep cycle batteries, or is called leisure batteries, operate in a manner compared to regular car batteries as they are built to deliver consistent and dependable power output, for prolonged durations.

Car batteries usually are made of lead acid components, with two lead plates immersed in an acid electrolyte solution – one plate is covered in lead dioxide ( charged terminal) while the other has spongy lead (negatively charged terminal).

When a device is linked to the battery there is a chemical process that happens between the plates and the liquid inside. This process leads to the production of electrons at one end. The acceptance of electrons, at the end resulting in the flow of electricity.

Charging the battery involves using a power source, like a converter or solar panel to supply a voltage than the batterys full charge voltage.This higher voltage triggers a chemical reaction where the lead dioxide and lead sulfate on the plates convert back to lead and lead dioxide respectively.This process effectively restores the batterys energy for use.

Below is the specified format, for charging voltage in a deep cycle lithium battery system.

 

Common Signs of Potential Battery Issues

Lead acid AGM RV batteries typically last between 2 to 5 years, depending on factors such as depth of discharge, environmental temperature, and maintenance practices.

Technician Tip: Lithium batteries can be fully discharged, but lead-acid batteries should ideally remain above 50% discharge.

A fully charged lead-acid battery should register between 12.4 and 12.8 volts on a digital multimeter. If the voltage drops below 11.6 volts DC, your RV’s 12-volt electrical systems may begin to experience issues.

Different battery chemistries have distinct voltage ranges. For example, lithium-ion batteries typically reach a peak of 14.1 volts DC, while lithium iron phosphate batteries can go up to 14.6 volts DC. These voltage thresholds assist modern RV converters and chargers in identifying the battery type being used.

Technician Tip: Not all battery chemistries are suitable for every application, environment, or charging rate. If you’re thinking about replacing your current RV battery with one of a different chemistry, be aware that modifications to the placement or system may be required to ensure safe and reliable operation.

Here are some signs that your battery may not be performing optimally:

• Dim or flickering lights
• Slow operation of slide-outs
• Furnace failure to ignite
• Slow functioning of hydraulic stabilizing jacks
• Frequent circuit breaker trips or blown fuses
• Automatic leveling jacks entering fault mode or losing zero-point calibration
• Increased frequency of recharging

Why RV House Batteries Not Charging and TroubleShooting

When shore power fails to charge your RV's house batteries despite powering your vehicle, a methodical approach is crucial to identify the root cause, commencing with the following steps:

1. Assess Your RV Converter's Charging Design

Begin by confirming whether your camper's or travel trailer's battery charges while plugged in. Essentially, is your converter meant to automatically charge the house batteries when connected to shore power?

Generally, modern converters are designed for this purpose. However, in the case of older campers, their converters might not have been engineered with battery-charging capabilities. Given the distinct nature of each motorhome, consulting your owner's manual for model-specific information is paramount. It's possible that there's a separate document dedicated to your converter in addition to the owner's manual.

If you lack access to your owner's manual, reaching out to your RV dealership or visiting the manufacturer's website to procure a new copy is recommended.

It's essential to ascertain your RV converter's capacity to charge house batteries; without this confirmation, all troubleshooting efforts may be futile. Once you've confirmed the converter's suitability for this function, you can proceed with further diagnostics.

If your converter is not designed for this purpose, you can consider integrating an MPPT solar charge controller or a DC-DC charger to supplement your charging needs.

2. Inspecting Wiring and Fuses

Before proceeding, it is crucial to ensure that your RV is disconnected from the 120v power source. Once assured, follow these steps to inspect the wiring and fuses:

Survey all the wires emanating from your RV converter for any visible issues. Look for wires that are:

• Loose or damaged
• Melted or discolored
• Bare wires in contact with each other

If present, tighten any loose connections, replace damaged wires, and then check if your RV batteries begin charging.

While inspecting the wires, also search for any inline fuses that might have blown. If found, replace them with fuses of the same amp rating to prevent overheating and potential fire hazards in your RV.

Additionally, scrutinize the wiring and fuses connected to your RV batteries. Look for signs of fraying, looseness, discoloration, or wires in contact with each other. If blown inline fuses are detected, replace them as needed.

In complex RV electrical systems, a wiring diagram can be helpful. Check your owner's manual or the manufacturer's website to see if one is available.

Once the thorough inspection of wiring and fuses is complete, you can proceed.

3. Examining Battery Terminal Conditions

Next, inspect the battery terminals for visible corrosion and ensure that the battery cables are tightly fastened to the battery posts. Corroded battery connections are a common reason for house batteries not charging when plugged in.

If corrosion is evident:

• Create a thick paste by mixing two tablespoons of baking soda with two tablespoons of water.
• Disconnect the power and ground wires from the battery terminals.
• Use the paste and a wire brush to clean the terminals and wire connections, removing the corrosion.
• Wipe the terminals clean with a paper towel.
• Reconnect the power and ground wires to their respective battery terminals, ensuring a secure connection.

If the RV battery still doesn't charge, proceed to the next step.

Related reading: What Causes Battery Terminal Corrosion And How To Prevent?

4. Reviewing Breakers and Fuses

Locate your RV's fuse and breaker box, usually found in the same compartment as the power converter. Check for tripped breakers and blown fuses within these panels. Refer to the owner's manual or look for markings near the breakers and fuses to identify each one.

Ensure all breakers are in the "on" position and replace any blown fuses, if found.

5. Checking the Battery Disconnect Switch

Confirm that the battery disconnect switch in your RV or 5th wheel is in the "on" position as this can impact battery charging. Consult your owner's manual for the switch's location.

6. Assessing Battery Condition - Battery Sulfation and Corrosion Removal

Sulfation is a leading cause of battery failure that develops gradually as a battery goes through multiple charge and discharge cycles. This process results in the formation of sulfate crystals, which can create a greenish-white buildup on and around the battery terminals. This buildup hinders proper electrical connections and reduces the battery's charging efficiency. Factors that increase sulfation include overcharging, undercharging, storing the battery in a discharged state, and allowing electrolyte levels to drop below the lead plates, which exposes them to air.

To prevent sulfation and maintain peak battery performance, it's important to handle the battery properly after discharge. Regularly check the electrolyte levels (at least once a month) and ensure the battery is fully charged before conducting maintenance. Since electrolyte levels fluctuate with the battery's charge level, be mindful of this when inspecting and adjusting them.

Steps to Remove Battery Corrosion

Follow these steps to safely clean corrosion from battery terminals:

1. Disconnect the Battery: Begin by disconnecting the cables, starting with the negative terminal. Avoid touching both terminals at once.

2. Neutralize the Acid: Sprinkle a ring of baking soda on the corroded terminals to neutralize any sulfuric acid.

3. Brush with Water: Using a soft brush dipped in water (like a paintbrush), gently brush the baking soda on the terminals. Let the mixture fizz for a few minutes to neutralize any acid.

4. Scrub the Terminals: Use a firm brush, like a toothbrush, to scrub the baking soda mixture into the terminals, paying close attention to the cable clamps.

5. Let the Mixture Sit: Allow the baking soda solution to sit for a couple of minutes to ensure thorough acid neutralization.

6. Wipe Clean: Wipe off the terminals with a clean rag, taking care to avoid skin, clothing, or any surface that could be damaged by acid residue.

7. Seal the Terminals: Apply a high-quality sealant spray to the terminals to protect against future corrosion.

Following these steps will help keep your battery terminals clean, ensuring better performance and prolonging battery life.

7. Inspecting the Converter

To begin, verify if your power converter is generating 13+ DC volts. Perform this check by measuring the voltage at the battery while connected to shore power.

Using a voltage meter, you should observe approximately 13.5 volts at the battery.

Subsequently, disconnect your RV from shore power and re-measure the battery's voltage. This time, you should notice a voltage drop.

This brief test will ascertain the proper functioning of your converter.

If it fails this test, various issues could be at play, such as a cooling fan problem within the converter, a defective thermal sensor, or a malfunctioning circuit board.

However, it is strongly advised not to attempt to open or manipulate the converter unless you are an RV Technician. Instead, it is prudent to take your vehicle to a certified RV technician who can address and rectify the issue.

How to Keep RV Battery Healthy

When performing RV battery maintenance, safety should always be a priority. Follow these essential precautions:

• Disconnect the battery from all power sources before beginning any maintenance.
• Wear rubber-soled shoes or stand on a rubber mat to prevent electrical shocks.
• Wear thick rubber gloves to protect your hands from accidental contact with corrosive materials or electrical components.
• Protect your eyes by wearing goggles to prevent battery acid or debris from harming your eyes.
• Do a visual check of the battery for issues such as frayed wires, split casings, corrosion, cracks, or leaks.
• Use only distilled water when topping up your battery’s fluid levels.
• Work in a well-ventilated area to avoid inhaling harmful gases that may be emitted from the battery.
• Seek professional help if you’re unsure about any aspect of battery maintenance or encounter any issues beyond your expertise.

Basic RV Battery Maintenance

Here’s a quick guide to basic RV battery maintenance to keep your system running smoothly:

• Inspect for damage: Look for fraying, split wire casings, corrosion, cracks, or leaks around the battery.
• Check power levels: A fully charged 12-volt battery should read around 12.7 volts. If it’s lower, charge it; if it’s higher, use some of the RV’s power until it stabilizes at 12.7 volts.
• Top up with distilled water: Check the fluid levels and add distilled water as needed to maintain proper battery function.
• Remove corrosion: Clean any corrosion from the battery terminals and connectors with a suitable cleaning solution or mixture of baking soda and water.
• Check connections: Ensure that the battery connections are secure and tighten any loose terminals.

For optimal battery performance:

• Check monthly: Inspect your battery at least once every month for the first 90 days of use.
• Proper storage: If your RV is in storage, remove the battery. Store it in a warm, dry place, preferably off the ground and on a piece of cardboard.
• Use a trickle charger for lead acid battery: Keep the battery charged with a trickle charger or ensure it is charged during regular check-ups.

These simple steps can significantly extend the life of your RV battery and help avoid costly repairs.

Conclusion

In conclusion, experiencing RV battery not charging when plugged in can be frustrating, but it is a common issue that can be resolved with proper troubleshooting. By checking the power source, fuses, connections, and the condition of the battery, you can often identify the cause of the problem. However, if the issue persists or if you suspect a faulty converter or inverter, it is advisable to consult a professional RV technician for further assistance.

FAQs about Charging RV Batteries

1. How do I know if my RV converter is charging my battery?

When the battery is charging, you may notice enhanced performance from your RV's electrical appliances. Brighter lights, a stronger water pump, and improved operation of other electrical devices are all signs that the converter is effectively charging the battery.

2. Can a dead RV battery be recharged?

Yes, a dead RV battery can often be recharged, depending on the type and condition of the battery. If a battery has simply been discharged (drained of power), connecting it to an appropriate charger or allowing it to charge through the RV's converter may restore it. However, if the battery has been deeply discharged multiple times, it may have suffered from sulfation, a process that can damage lead-acid batteries and reduce their ability to hold a charge.

For a lead-acid battery, using a smart charger or a desulfator can sometimes help rejuvenate a deeply discharged battery. LiFePO4 (lithium iron phosphate) batteries, on the other hand, are more resistant to deep discharge issues and can usually be recharged from a low state. However, if a lithium battery’s built-in battery management system (BMS) has disconnected it due to low voltage, you may need a charger capable of jumping start the battery.

3. Can LiFePO4 RV Batteries Be Charged to 100%?

Yes, LiFePO4 batteries can be safely charged to 100%. Unlike some other lithium battery types, LiFePO4 batteries are engineered to handle full charges without significant risk of damage. For optimal longevity, however, it's advisable to maintain the battery's state of charge (SoC) between 20% and 80% during regular use.

4. Is It Harmful to Fully Discharge a LiFePO4 Battery?

It's not recommended to completely discharge LiFePO4 batteries. While they can tolerate deeper discharges better than lead-acid batteries, repeatedly allowing them to drop to 0% can negatively impact their lifespan and performance. Ideally, you should recharge the battery before it falls below 20%.

5. Is It Safe to Leave a LiFePO4 Battery on the Charger?

While it’s generally safe to leave a LiFePO4 battery on the charger—thanks to the built-in battery management system (BMS) in both the charger and the battery—it's still wise to monitor the charging process. Once fully charged, it’s best to disconnect the battery promptly to prevent unnecessary wear.

6. Why Is My RV Battery Not Charging While Towing?

The tow vehicle can recharge your RV’s battery through the electrical connector when towing, especially if you’re using a 7-pin connector that includes a dedicated charging wire.

Tip: If your connection is a 4-pin connector, it is not designed to charge your RV battery while towing.

To check if your battery is receiving a charge, use a digital multimeter set to measure DC voltage. With your RV connected to the tow vehicle, the battery voltage should read above 12.8 volts, indicating that it is receiving a charge through the 7-pin connector. If the reading is below 12.8 volts, further investigation is needed.

Start by confirming that there is 12-volt power coming from your tow vehicle to the 7-pin plug. Start your tow vehicle, then connect the black test lead of your multimeter to the ground probe and the red test lead to the battery power probe. If you don’t detect voltage at the plug, you may need to check the fuses under the hood of your tow vehicle.

If you do find voltage at the plug but your RV battery still shows less than 12.8 volts, there may be a wiring issue or a battery solenoid in-line that needs attention.

7. Why Won't My RV Battery Hold a Charge?

Discharging an RV battery for longer than recommended is the most common reason a battery won't hold a charge. Most RV batteries shouldn't be drained to more than 50% of their capacity before being recharged.

Beyond that, factors such as age, incorrect charging voltage, and incorrect charging method can affect a battery's ability to hold a charge as expected. If your battery isn't holding a charge:

• Check the date stamp. RV batteries older than six years should be replaced.
• Ensure the correct charging voltage and method. Avoid using accessory battery chargers (such as car chargers) that don't match the battery manufacturer's voltage specifications.

If you have questions about finding a replacement RV battery, please contact service@litime.com.