When not connected to shore power, you rely on your RV batteries to power lights and select appliances, like your water pump. RV electrical systems are designed to recharge your batteries when connected to shore power.
Most towable RVs are also designed to recharge the batteries when the 7-pin connector is attached to your tow vehicle and its engine is running. In most motorhomes, the electrical system pulls power from the alternator to recharge your coach battery while the engine runs. Check your owner’s manual to confirm if this is the case for your RV.
This is how these systems should function. But what happens when you find yourself asking: Why is my RV battery not charging?
Let’s examine some common issues and troubleshooting tips you can use to determine your best path forward.
Common Signs of Potential Battery Issues
Generally, RV batteries will last 2-5 years or longer. The lifetime of an RV battery depends on the type of battery, the depth of discharge, the temperature of the environment it’s used in, and the degree of proper maintenance.
Technician Tip: Lithium batteries are designed to be fully discharged, but lead acid batteries should be maintained above 50% discharge.
A fully charged lead acid battery should register between 12.4 and 12.8 volts when measured with a digital multimeter. When a lead acid battery’s charge falls below 11.6 volts DC, your RV’s 12-volt electrical devices will begin to fail.
Batteries with other chemistries will be slightly different. Lithium-ion batteries reach 14.1 volts DC, while lithium-iron phosphate batteries top out at 14.6 volts DC. These limits allow newer RV converters/chargers to tell which battery is used.
Technician Tip: Not all battery chemistries are suitable for every condition, location, use, or charge rate. Be careful when considering swapping an existing RV battery for a fancy new battery of a different chemistry. Other modifications to the placement or system may be required for safe, reliable operation.
Here are some indicators your battery isn’t performing as it should:
- Dim or flickering lights
- Slow slide-out operation
- The furnace won’t light
- Slow operation of hydraulic stabilizing jacks
- Constant tripping of circuit breakers or popping of fuses
- Automatic leveling jacks may lock out in fault mode or lose zero-point calibration
- Increased recharge frequency
Why Is My RV Battery Not Charging While Plugged In?
There are several possible reasons a battery won’t charge while your RV is plugged in. In addition to reading through these potential causes, you can download this decision tree to help troubleshoot your battery charging issue.
No AC Power
The first, and arguably easiest, thing to check is the 120-volt power source. If the breakers aren’t on and you don’t have 120-volt AC power coming in, there’s nothing to convert, and your battery won’t charge.
Check that the breakers aren’t tripped. Check the completion of all electrical connections to the breaker, between your surge protector and shore power cord, from the cord to your RV, and between your cord and any electrical adapters you might be using.
Technician Tip: Breakers on campground power pedestals are most likely to trip during times of high usage (i.e., holidays like the 4th of July) because campers are most likely to plug in extra lights and powered accessories at these times.
You can also use our 120V AC Decision Tree to help troubleshoot shore power issues.
Battery Disconnect Switch In The Wrong Position
Another common problem is that the battery disconnect switch is improperly positioned. This switch is great for storing your RV because it eliminates the potential for a slow battery drain when you’re not using your RV.
But suppose you don’t change it back to the proper position when you start camping again. In that case, you won’t be getting power from your battery to your RV’s electrical system, and your system also won’t recharge the battery when plugged into shore power.
Incomplete Battery Connections
A third potential reason your battery isn’t charging could be that your battery cables are disconnected. If your RV isn’t equipped with a battery disconnect switch, you likely remove the battery cables for storage. If these cables aren’t securely connected and tightened when it’s time to camp again, your battery won’t charge or provide power.
Technician Tip: This is a great time to check battery cables and terminals for corrosion and clean them up if needed.
Next, an incomplete ground may prevent your battery from charging. Some RV battery cables run from the battery into a 12-volt distribution panel. Others are grounded by being connected directly to the chassis. In either format, the ground should be secure and corrosion-free to help protect your system and keep charging your battery as engineered.
Blown Fuses or Tripped Breakers
The next possible reason is broken fuses or tripped breakers. Locate your RV’s circuit breaker panel. First, check the breaker associated with your RV’s converter. If this breaker is tripped, the converter won’t recharge your battery when connected to shore power.
Technician Tip: If your circuit breaker panel isn’t properly labeled, now is a great time to bring it into a Camping World Service Center to have a certified technician test and label it for you!
Why Is My RV Converter Not Charging The Battery?
As mentioned above, check that the breaker for your RV’s converter hasn’t been tripped before considering whether your converter has gone bad. But if you’ve completed the checks above, it might be time to assess the operation of the converter itself.
To do this, you’ll need a digital multimeter. This great tool should be in every RV tool kit, and they’re relatively affordable to acquire. With yours in hand, set it to measure DC voltage (Ian explains more in the video above!).
Our first check assumes the battery was fully charged to begin with. Contact the test leads to the posts on your RV battery and check the display. It should measure more than 12.8 volts, indicating an incoming charge.
If your battery wasn’t fully charged, check the battery’s voltage before plugging in the RV and then again after connecting to shore power. The voltage should increase by at least 0.5 volts DC if the converter is working and all fuses, breakers, switches, and wiring are correct.
Why Is My RV Battery Not Charging While Towing?
Your tow vehicle may be able to recharge your RV’s battery through the electrical connector that you connect to your tow vehicle. This is the case for towables and tow vehicles that use a 7-pin connector with a charging wire dedicated to this purpose.
Technician Tip: If your connection uses a 4-pin connector, your setup isn’t designed to charge your RV battery while towing.
Like testing your converter above, you can use a digital multimeter set to DC voltage to test that your battery voltage is above 12.8 volts when connected to your tow vehicle. That signals an incoming charge through the 7-pin connector. If your measurement is lower than 12.8 volts, it’s time to troubleshoot.
You need to begin by verifying there is 12-volt power coming from your tow vehicle to your 7-pin plug. Here’s a diagram telling you which lead is responsible for 12-volt charging:
Start your tow vehicle and place your multimeter’s black test lead on the ground probe and the red test lead on the battery power probe. Verify you’re getting voltage to the plug because, if you’re not, you’ll probably need to pop the hood of your tow vehicle and check the fuses.
If you get voltage to the plug but still don’t see more than 12.8 volts when testing your RV battery posts, you may have a wiring issue. You may also have a battery solenoid in-line. I recommend contacting a Camping World Service Center to schedule further electrical testing if this is the case.
Why Does My RV Battery Not Hold a Charge?
Discharging your RV battery farther than is recommended is the most common cause for batteries failing to hold a charge. Most RV batteries shouldn’t be depleted past 50% of their capacity before recharging.
Beyond that, factors like age, incorrect charging voltage, and incorrect charging method can also impact your battery’s ability to hold a charge as intended. If your battery doesn’t hold a charge:
- Check the date stamp. RV batteries that are more than six years old should be replaced.
- Ensure correct charging voltage and method. Avoid using an accessory battery charger (such as a car charger) that doesn’t match your battery manufacturer’s voltage specifications.
Consult a Camping World Service Center if you have questions about finding a replacement RV battery.
Our battery troubleshooting article is another great resource for tips on locating, testing, and keeping your RV battery charged.
What questions do you have about using and maintaining your RV battery? Let us know in the comments below.