When plugging your RV house battery into shore power, you may wonder whether you need to disconnect the battery. Might leaving the battery connected lead to an overcharge?
The answer to whether you should disconnect your RV when plugged in is that it depends. Generally, it is safe to leave the battery connected. However, in certain conditions, it is recommended to disconnect your RV battery if you plug into shore power. This article will expound further. But first, let’s look at how the RV electrical system works.
RV Electrical System Overview
An RV has two main electrical systems: AC and DC. The two systems are separate and serve specific purposes.
The DC power is the primary power source in RVs and serves as the battery bank. Most RVs have a DC power battery voltage of 12 volts. The power is used for powering lights, certain power appliances, etc.
On the other hand, the AC power system is activated when the RV is plugged into shore power. You can use it to power your RV’s non-DC appliances and personal electronics. Most RVs have a 120-volt AC system.
An RV’s electrical system’s other two important components are converters and inverters. Converters change AC power to DC, while inverters change DC power to AC. Most RVs come with a converter as standard. This enables you to charge your RV battery when plugged into shore power. The RV converter converts the 120V AC power to a 12V DC current.
So, Should You Disconnect Your RV Battery When Plugged In?
Typically, it is not necessary to disconnect an RV battery when it is plugged in. However, this is on the condition that the RV’s charging system is working properly. In that case, keeping the battery power plugged in for your camper or RV may help maintain its charge and extend its lifetime.
When to Disconnect Your RV Battery When Plugged In
Below are the circumstances under which it would be ideal to disconnect your RV battery when plugged in.
1. If you intend to store the RV for an extended period
If you intend to store the RV for an extended period of time — more than one month – it is best to disconnect the battery to prevent parasitic draining over time. Although the RV may not be used, electrical components such as the alarm system draw power from the battery.
Therefore, DC power does not flow to these systems when you disconnect the battery. Some people take out the battery from the RV and store it indoors, connected to a smart charger for optimal maintenance.
2. If the charging system is faulty
Another reason it would be appropriate to disconnect the battery is if the charging system is faulty. In this case, keeping the battery connected can result in overcharging, which could damage it and other RV components. For example, if your RV’s converter is faulty or without overcharge protection, it can cause a power surge.
3. If you are conducting maintenance and repairs on the RV electrical system
Disconnecting the battery to prevent electrical shock or damage to the various components is recommended. You should also disconnect the RV from shore power. The precaution is particularly important when you are tampering with the electrical wiring. For example, if you are changing a light fixture or fixing a fan.
4. If the RV has a 7-pin connection to the tow vehicle
While the 7-pin connection makes it possible to recharge your RV batteries during trips, if left plugged into the tow vehicle for extended periods without the tow vehicle running, it can result in the battery draining. Some RV vehicles are designed such that the power supply to the pin switches off once the ignition is switched off, preventing the batteries from draining.
5. If you are using an external smart charger or a solar panel charger
Older RV converters have limited charging capabilities and a trickle charger, whereby they trickle charge over an extended period. In comparison, newer RVs have more sophisticated 3-stage chargers, which charge faster. They are safer even if the battery is connected to shore power as they do not overcharge.
How to Disconnect a Battery When You Plug In
If you opt to disconnect the battery, many modern RVs have an RV battery disconnect switch that you can switch off. The battery disconnect switch is usually located near the battery, either in the maintenance bay or the battery compartment. If your RV or camper has no RV battery disconnect switch, you can have one installed aftermarket.
So, should I disconnect my RV battery when plugged in? Generally, it is ok to leave the battery connected when you plug in the RV. However, if the charging system is faulty, you will be storing the RV for a long time, or for any of the other reasons described above, it is best to disconnect the battery. If you are unsure what to do, consult a qualified RV technician or check your manufacturer’s manual.