Home Blogs-LiTime Lithium Blogs RV Battery Not Charging When Plugged In? With Troubleshooting
charge battery
RV

RV Battery Not Charging When Plugged In? With Troubleshooting

John Marius
John Marius
—
22/01/2024

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).

starter vs deep cycle battery

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.

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.

Note: 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

TroubleShooting of RV Batteries Not Charging When Plugged in

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

1. Check If There is AC Power

The first and easiest thing to check is the 120-volt power. If the circuit breaker is not on and there is no 120-volt AC input, the conversion cannot take place and the battery cannot charge.

Check for tripped circuit breakers. Check all electrical connections between the circuit breaker, surge protector and shore power cord, between the power cord and the RV, and between the power cord and any power adapters you may be using.

Tech Tip: Circuit breakers at campground power pedestals are most likely to trip during peak usage times (i.e., holidays like the 4th of July) when campers are most likely to be plugging in extra lights and live accessories.

2. Assess Your RV Converter's Charging Design

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.

dc-dc charger

3. 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.

4. 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.

5. 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.

6. 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.

7. Check the Battery's Connection

Another possible reason why your battery won't charge could be a disconnected battery cable. If your RV isn't equipped with a battery disconnect switch, you may have removed the battery cables for storage. If these cables aren't securely connected and tightened when you go camping again, your battery won't charge or provide power.

Technician Tip: This is a perfect time to check the battery cables and terminals for corrosion and clean them if necessary.

8. Incomplete Ground

An incomplete ground can hinder your battery's charging process. In many RV setups, battery cables connect the battery to a 12-volt distribution panel, while others may be grounded directly to the chassis. Regardless of the configuration, it's crucial that the ground connection is secure and free from corrosion. This ensures your system operates effectively and keeps your battery charging as intended.

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.

7 pin connector for rv towing

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.

Basic RV Battery Maintenance Tip

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.

Why Won't My RV Battery Hold a Charge?

One of the most common reasons an RV battery fails to hold a charge is excessive discharging. Most RV batteries should not be drained below 50% of their capacity before recharging.

In addition to over-discharging, several factors can impact a battery's ability to retain a charge, including age, incorrect charging voltage, and improper charging methods. If your battery isn't holding a charge, consider the following:

  • Check the Date Stamp: AGM RV batteries older than six years may need replacement.
  • Verify Charging Voltage and Method: Ensure you are using the correct charging voltage and method. Avoid using accessory battery chargers, like car chargers, that do not match the battery manufacturer's specifications.

If you need assistance finding a replacement RV battery, please reach out to service@litime.com.

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.

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%.  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.

John Marius
John Marius
John Thompson, an automotive engineer with 15+ years of EV and lithium battery experience, holds a Master’s in Electrical Engineering from Stanford. He’s passionate about advancing battery tech and promoting green energy.

Join LiTime

Life & Discovery
Email Address *

You May Like

LiTime 12V (14.6V) 10A LiFePO4 Battery Charger
LiTime 12V (14.6V) 20A LiFePO4 Lithium Battery Charger

Recent Post

[Full Guide] How Do You Store LiFePO4 Lithium Batteries
13/06/2023
Can I Charge A LiFePO4 Battery with a Normal Charger
25/06/2023
LiFePO4 Temperature Range: Discharging, Charging and Storage
19/12/2023
The Ultimate RV Inverter Installation Guide
13/05/2024