Considering switching to lithium-ion batteries for your RV? They are an amazing power source, but you may need to consider making a few upgrades alongside the batteries to get the most out of your new power system. One of the most common questions we get asked about lithium is what do I need to upgrade in addition to the batteries? In this article, we will be answering this question.
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Why Switch to Lithium-Ion Batteries?
Lithium batteries are becoming more and more popular for good reason. In energy storage applications, lithium-ion batteries provide more power than other battery types when taking weight and size into consideration. They also last much longer and charge better. Lithium also can be installed in enclosed spaces because they do not emit any gasses. We did a deep dive on the cost of lithium and even found that over its life, it’s the cheapest battery for power applications.
In addition to all the power benefits, lithium-ion RV batteries eliminate the dreaded “battery anxiety.” Meaning, you get overly obsessed and worried about your batteries’ state of charge and health. Lead-acid batteries require such specific charge parameters it’s easy to damage them by over-discharging or not properly charging them. With lithium-ion, you don’t have to think about your batteries all the time. They just work! Lithium-ion batteries also have such a long life, in most applications, they are a lifetime battery.
We personally recommend Battle Born Batteries as they are high quality American made and engineered, however most lithium will get you these benefits.
Differences in Charging
Charging is what you need to consider most when making the switch to lithium-ion batteries in your RV. Most of the time, the switch is from lead-acid to lithium, and these batteries have significantly different charge profiles.
Lead-acid batteries have three different charging stages. Most lead-acid battery chargers will step through them based on the battery voltage and internal resistance. These charging stages are bulk, absorption, and float. The absorption stage is a special phase where the voltage is held higher to force current into the battery as the resistance increases. In this phase, charging slows way down and is another big drawback to lead-acid batteries.
In lithium batteries, the absorption phase is not required. This is because the lower internal resistance of the batteries allows them to charge at full speed to almost completely full. Because of this, lithium batteries can charge much faster than many other types of batteries. Additionally, they are a better choice for solar energy as they will not waste power due to a slowing charge.
What Other Components Need to Be Upgraded With The Lithium Batteries?
This article is referring to drop-in lithium-ion RV batteries. These batteries have built-in BMS (battery management system) units and are designed to be used in place of traditional lead-acid batteries. If you are considering building your own battery from cells or using batteries without a BMS, like electric car batteries, then you will require more equipment to make sure your batteries operate safely. Do not connect any charger to lithium batteries without a BMS unless you have other safety measures in place.
Now that we have an understanding of the charge differences, it’s clear that a lithium-specific charger will be beneficial. The benefit is typically faster charging. Yet, this does not mean that a lead-acid battery charger will not work. Most of the time, drop-in lithium iron phosphate batteries will work with existing equipment as long as the charger does not have automatic equalization.
Usually, if the battery charger is programmable, you can reprogram it to work with lithium. However, sometimes a charger will only have different charge profile settings. If there is no lithium setting, AGM is usually the best choice. Conversely, if the charger is fully programmable, it’s always best to get the proper voltage settings for bulk, absorption, and float from the manufacturer of your lithium-ion batteries.
Do Not Use Automatic Equalization With Lithium
Equalization is required in lead-acid batteries for longevity and health but not required in lithium. An equalization charge increases the voltage much higher than normal to “equalize the lead cells.” If this is done on lithium batteries, it can damage their BMS. That’s why you should permanently disable automatic equalization. If you cannot disable automatic equalization on a lead-acid battery charger, replace it.
Along with the primary battery charger, any solar chargers also need to be compatible with lithium RV batteries. Most of the time, solar chargers will not have any equalization capabilities and will work with lithium. But they may charge a bit slow. Some charge controllers are programmable and you can reprogram them to the appropriate voltages for the batteries. In this case, research the manufacturer of your batteries to get the proper voltage settings.
Typically, inverters do not mind running on lithium batteries. As long as they are in the right voltage range (12, 24, or 48 volts), they should work. However, you should change the low voltage cutout, if the inverter has one. Lithium battery manufacturers will provide a recommended low voltage cutout for inverters.
Other Considerations When Replacing Lithium-Ion Batteries
Usually, loads like lights, water pumps, and appliances will not even know they are running on a different type of battery. Therefore, you don’t need to change anything with them.
I always recommend installing a shunt based battery monitoring system with lithium-ion batteries to accurately monitor the state of charge. My favorite monitor is the Victron BMV712.
- The Victron Energy BMV-712 is a high precision smart battery...
- Built-in Bluetooth Communication - Monitor your batteries on...
- Next to the basic display options, such as voltage, current, and...
Lithium-ion batteries are often replaced in vehicle house systems that are tied to an engine’s alternator system. A trailer charges through the tow vehicle, a motorhome charges off the engine, and the same with a boat. Because of the lower internal resistance of lithium, it is not uncommon to see lithium batteries burn up fuses or even the alternators themselves. We wrote a blog all about how we set up alternator charging in one of our builds. I recommend if you want to charge lithium batteries off an alternator, to use a DC-DC converter that will keep the current at a safe level.
- Victron Energy Orion-Tr Smart 12/12-Volt 18 amp 220-Watt DC-DC...
- Is suitable for both lead acid and lithium batteries, Unlimited...
- Bluetooth Smart enabled: The unit can be monitored and programmed...
A DC-DC charge controller should be fully programmable so you can set the appropriate voltages and current limits.
Lithium Upgrades Made Easy
Overall, what you need to change or replace is going to depend heavily on your current system. If you are running a basic charger without equalization, you can use a drop-in lithium RV battery without changing much else. However, reprogramming or replacing the charger would be the best improvement you could make when switching to lithium as you will get faster charging. If you choose to switch out components, we highly recommend getting fully programmable equipment and programming your chargers and inverters to meet the manufactures recommendations.
An upgrade to lithium-ion RV batteries may seem daunting, but depending on your needs a simple drop-in replacement might suit your needs with minimal upgrades needed.
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