In the table below, you’ll find the different classifications of RVs, their typical power systems, and the Power Sonic lithium batteries we recommend for each type of RV. Please note that these batteries are for home power only and are not suitable for starting applications (e.g. starting a Class A, B or C motorhome).
Why choose an RV lithium battery?
The Power Sonic Lithium Iron Phosphate (LiFePO4) battery provides everything necessary to support your life on the road. Designed for use in the toughest conditions, this battery allows you to travel farther and more efficiently while maintaining reliability and performance.
More usable power
Lithium batteries allow you to utilize 100% of their capacity, regardless of discharge rate. In contrast, lead-acid batteries only provide 60% of their rated capacity at high discharge rates such as 0.8C. This means you can confidently use all your electronic devices, as lithium batteries have plenty of remaining capacity.
Ultra-Safe Chemistry
Power Sonic Li-Ion batteries use LiFePO4 chemistry, which is recognized as the safest Li-Ion battery chemistry available. To further enhance safety, our lithium RV batteries are equipped with an advanced Protection Circuit Module (PCM) that protects against overcharge, overdischarge, overheating and short circuit conditions.
Longer Lithium Battery Life
Power Sonic RV lithium-ion deep-cycle batteries have 10 times the cycle life of lead-acid batteries. This dramatically reduces the cost per cycle of lithium batteries compared to lead-acid batteries, so you’ll have to replace your RV’s lithium battery less often.
Lithium charges faster
Lithium batteries charge up to four times faster than lead acid batteries. Fast charging means the battery lasts longer. In addition, it can quickly and efficiently store the energy generated by the solar panels integrated into the caravan.
Lithium batteries are lighter in weight
Lithium batteries are 50-70% lighter than lead-acid batteries of the same capacity. This can result in a weight reduction of 100-200 pounds for larger RVs.
Flexible Installation
Power Sonic lithium batteries can be mounted upright or on their side, making them flexible to install and easy to configure.
Alternative to Lead-Acid Batteries
Power Sonic lithium batteries are available in a variety of BCI standard pack sizes and can be used as an alternative or upgrade to lead acid batteries.
Low Self-Discharge
The low self-discharge rate of lithium batteries ensures worry-free storage. Even with seasonal use, you can rest assured that the batteries won’t let you down. We recommend that all lithium batteries be checked for open circuit voltage (OCV) every six months.
Maintenance-free
With a plug-and-play design, simply connect the batteries and go! No need to add water, completely maintenance free.
Charging Lithium Caravan Batteries
In addition to the various types of recreational vehicles, there are a variety of charging sources and charging methods for RVs. When discussing charging sources, we are referring to how electricity is produced. Common sources include:
- Shore power – The RV is connected to an AC outlet.
- Generator – The RV is equipped with a generator for power and battery charging.
- Solar – R Vs are equipped with solar panels for power generation and charging.
- Alternator – The RV engine charges the batteries while running.
Methods are how the voltage and current are controlled during the charging process. These methods include:
- Trickle charging
For more information on the advantages of lithium batteries, check out our article on the advantages of solid state batteries.
Constant Voltage and Current Limiting Float Charger
- Constant current limit constant voltage float charging
- Multi-stage charging system: constant-current high-current charging, constant-voltage absorption charging and float charging to keep the battery at 100% state of charge (SoC).
In a motorhome, there may be multiple battery charging methods, but typically a single charging method is used in the motorhome. The main difference between these methods is the speed at which the battery is charged. Multi-stage charging systems are designed to charge the battery as quickly as possible.
For sealed lead acid (SLA) and lithium batteries, the charging settings differ only slightly for current and voltage. Sealed Lead Acid (SLA) batteries are typically charged at 1/10 to 1/3 of their rated capacity, while Lithium batteries are charged at 1/5 to 100% of their rated capacity, resulting in a much shorter charging time. When switching from SLA to Li-ion batteries, the voltage settings for absorption charging or float charging are so close as to be negligible.
Types of chargers used
There is a lot of misinformation on the Internet about the charging parameters of SLA and LiFePO4 batteries. While RV charging systems will vary, this guide is intended to provide general information for the end user.One of the reasons Keheng chose Li-Iron Phosphate over other types of lithium-ion batteries is that Li-Iron Phosphate batteries have a voltage very similar to that of lead-acid batteries, with the exception that the lithium voltage is slightly higher, at 12.8V (compared to 12V for lead-acid batteries). The similarity in voltage also means that the batteries have similar charging characteristics.
As shown below, lead acid and lithium batteries have similar charging curves and roughly the same charging voltage. This means that an SLA charger will charge the battery normally, but you will not have the fast charging benefits of a Li-Ion battery and a Li-Po charger.
If you really want to take advantage of lithium chemistry, we recommend upgrading your charging system to a dedicated lithium charger. However, aside from charging speed, Li-Iron Phosphate batteries are hardly affected in any way when charging with an SLA charging curve or charger, as the SLA charging voltage is quite close to the lithium charging voltage.
In addition, Li-Ion batteries do not need to be kept on a float charge like SLA batteries. Lithium batteries actually prefer not to be stored at 100% State of Charge (SoC). If the circuit board of a LiPo battery has a protection feature (which our PSL-SC and PSL-BT batteries have), it will stop charging when the battery reaches 100% SoC, so the battery will not receive a float charge from an SLA charger, and will not suffer any degradation in battery performance as a result. It is also not recommended to use a charger with a sulfur removal mode, as this can damage the LiPo battery.
Series or Parallel Charging Lithium Ion RV Batteries
After purchasing an RV and upgrading the batteries to Li-Ion, you may be wondering how to charge these batteries.The SLA charging system is acceptable, but what about series and parallel charging?
You should charge your caravan’s lithium batteries in series and parallel (batteries in series and parallel) just as you would any other battery pack, so the caravan’s existing charging system should be sufficient in most cases. Lithium chargers and inverters can be installed to optimize charging performance, but a standard charging system will usually suffice.
For series connections, it is very important that all batteries are charged to 100% at the time of installation. Series voltage will vary from battery string to battery string. If any battery is charged beyond the battery protection limits in the battery management system/PCM board, this may cause problems.
When charging a battery pack, make sure the charger used can handle the total voltage of the series connection. For LiFePO4 batteries, the charging voltage per cell is typically 3.65V, and for 12.8V batteries, it is 14.6 V. Multiply the charging voltage by the number of cells in the string to get the total charging voltage. For example, if the total voltage of the string is 51.2V, the charge voltage should be set to 58.4V.
Charge the batteries at 1/3 C of the total rated capacity in a parallel connection. For example, if four 10 ampere-hour (AH) batteries are connected in parallel, they can be charged at 14 amps (A) because 1/3 of 40 is approximately 14. If the charging system exceeds the protection limits of a single battery, the BMS/PCM board will disconnect that battery and allow the remaining batteries to continue charging.
Sometimes it is possible to extend the life of a battery by removing it from the battery pack and charging it separately.
Kaihen PSL-SC and PSL-BTP batteries are an excellent alternative to standard SLA batteries in RVs. They offer the benefits of lithium technology and provide a seamless plug-and-play experience without changing your charging system. To learn more about the benefits of lithium technology over SLA technology, visit our blog. If you have any other questions about RV batteries and their charging systems, please feel free to contact us.