The real value of a battery only really comes to light when the use of the motorhome is restricted. The important power storage systems are often neglected and too rarely checked for their condition. But with which motorhome battery should you start your future trips? There are several factors to consider when purchasing and using it. The wet battery as well as AGM, GEL and lithium phosphate batteries all have their advantages and disadvantages, which you should take into account in the decision-making process.
Batteries in the motorhome existential
Most motorhomes (there are always exceptions) have two different batteries installed: The starter battery, which is located in the engine compartment, is responsible for the starter or the radio. It is used to start the engine with a short but strong impulse. Once this has been achieved, the alternator takes over the classic power supply in the vehicle. This is also the case with any car.
However, the power supply in a motorhome is much more complex. Without another battery, the water pump, TV, electric hob or light would not work. The classic starter battery cannot take over this functionality. Supply batteries are used here, which deliver a few amperes over several hours and, above all, are frequently rechargeable. Motorhome owners have the choice between wet batteries, AGM, GEL and lithium-ion batteries.
Charging cycles as an important purchase criterion
Regardless of the type, the charging cycles are an important purchase criterion when buying a motorhome battery. For manufacturers, this is often marked as a number of cycles. If, for example, the number of cycles is 750, the battery can be charged 750 times without major memory loss. Afterwards, recharging is still possible, but you have to expect that the capacity will continue to decrease.
Wet batteries are inexpensive, but maintenance-intensive
Wet batteries are often still found in older motorhome models. In terms of design, they are similar to the classic starter batteries, but their cycle stability is significantly increased. Due to the somewhat outdated technology, wet batteries are quite inexpensive to purchase, but associated with a high maintenance effort. The disadvantages are therefore obvious:
Regular checking of the acid level is necessary.
Water must be refilled as needed.
Resulting gases must be directed outwards via a valve.
There is a risk of leakage. The battery itself must therefore be stored inside an acid-resistant container.
Wet batteries should never be discharged less than half.
The service life is rather modest compared to the competition.
Although there are so-called “maintenance-free” wet batteries with VRLA accumulators, leaking gases and the depth of discharge are also decisive disadvantages for them.
GEL batteries: Maintenance-free vs. price & charging time
The biggest disadvantage of a wet battery is almost easily remedied by a GEL battery. The electrolyte is not liquid here, but is bound in a GEL battery. They are maintenance-free and are considered very durable, even under high stress. A high depth of discharge without consequential damage is a big plus for GEL batteries. Nevertheless, there are disadvantages that must be referred to:
The high internal resistance of GEL batteries often means that charging by solar power is insufficiently possible.
The consistency of the electrolyte in a GEL battery is perfect for high temperatures, but very susceptible to cold. In winter camping, performance can decrease rapidly.
The charging times of a GEL battery are relatively high compared to other types.
The purchase price is high, but can pay for itself due to the long service life.
AGM batteries with fast charging time
A completely different type of battery is AGM deep cycle battery. The term stands for Absorbent Glass Mat. Here, the electrolyte is stored in highly porous microglass fiber fabric. They are maintenance-free and the internal resistance is significantly lower. The advantages over GEL batteries are the fast charging time and the significantly higher resistance at low temperatures. The high capacity of the battery should also be emphasized. However, two disadvantages could give rise to criticism when purchasing:
AGM batteries are more sensitive to high temperatures. Accordingly, there may be a drop in performance here. In contrast to the GEL battery, frequent deep discharge is not advisable.
Lithium iron phosphate batteries (LiFePo4) for frequent use
The most modern technology is anchored in lithium iron phosphate batteries (Take 12v lithium battery for example), which combine several advantages: Lithium-ion batteries provide almost their entire capacity. A frequent, almost complete deep discharge is therefore no problem at all. They are very fast to load, also a small space miracle. With almost 3,000 cycles, even the high purchase price can be justified. Of course, lithium iron phosphate batteries are maintenance-free.
As disadvantages, only the high acquisition costs and the modern charging technology that is required can be listed.
How do I find the right motorhome battery for me?
For the purchase of a battery, your own energy balance is crucial. The high purchase price of a lithium iron phosphate battery can certainly be considered if you travel more often with your motorhome and have a correspondingly high consumption. For an annual holiday or weekend trip, AGM batteries or GEL batteries should meet all requirements. In this context, it is also helpful to identify the power guzzlers in your own motorhome. Similar to the household, there is a lot of savings potential, which ultimately also affects the frequency of charging.
Proper charging increases service life
Basically, it doesn’t matter where the battery gets new energy from. Dedicated battery charger, solar system, alternator or fuel cell are ideally suited to charge the on-board battery. Nevertheless, each battery should be connected to the 230-volt grid for twelve hours approximately every four weeks to ensure full charging. Most chargers have an IUoU characteristic curve, which guarantees an optimal charging time. In addition, they are individually adaptable for each battery type.