Frequently Asked Questions On Replace SLA Batteries with Li-Ion Technology

Lifespan and Costs

Budgets play a huge role in deciding which battery to get. With Lithium batteries being more expensive, to begin with, it can seem like a no-brainer to go with an AGM. But what causes this difference? AGM batteries remain less expensive because the materials used to make them are inexpensive and widely available. Lithium batteries, on the other hand, use more expensive materials with some being harder to come by Li-Ion Technology.

Another part of the decision-making process to consider is the lifespan of these batteries. This is where the initial cost of the Lithium could be offset. The following points highlight the differences between lithium and AGM:

● AGM batteries are sensitive to the depth of discharge. This means the deeper the battery is discharged, the fewer cycles it has.

● AGM batteries are generally recommended to only be discharged to 50% of their capacity to maximize their cycle life. This limited depth of discharge (DOD) of 50% means that more batteries are required to achieve the desired capacity. This means more upfront costs, and more space needed to store them.

● A lithium (LiFePO4) battery, on the other hand, is not affected much by depth of discharge so it boasts a much longer cycle life. Its DOD of 80-90% means fewer batteries are required to achieve the desired capacity. Fewer batteries mean less space needed to store them.

More on Frequently Asked Questions on Lithium Battery Power Centers later.

Are the Lithium Battery Systems Presently Available Safe for RV’s?

To answer this question you need to understand that there are several types of Lithium-Ion Batteries based on the composition of the different materials incorporated in their manufacture. These different compounds can provide additional power per Kilogram (2.2 Lbs.) of battery weight, however; this additional power comes at an increased risk of a thermal event.

Be assured that Lithium-Ion batteries are safe and heat-related failures are rare. The battery manufacturers achieve this by adding three layers of protection.

● Limiting the amount of active material

● Inclusion of safety mechanisms within the cells

● The addition of an electronic protection circuit in the battery including a Battery Management System (BMS)

The chart below compares the amount of power (Watt Hours) per Kilogram these various battery types can store. Note that the standard Lead/Acid Battery only stores 40 Watt-Hours, while the most efficient Lithium Battery, the NCA (Nickel, Cobalt, and Aluminum) battery, can produce 250 Watt Hours or over six times more than your present RV battery. If it weren’t for the cost and possible hazards this would be a great RV battery.

One of the requirements for a Lithium Battery to acquire this UL listing is a built-in BATTERY MANAGEMENT SYSTEM (BMS). This electronic package performs several functions to ensure safety and long battery life.

Safety Features of the BMS Include:

Constant monitoring of each of the four (3.2 Volt) Lithium Cells connected in series required to produce a 12.8 Volt Lithium Battery. This monitoring includes the Voltage of each cell for high or low voltage limits and disconnects the battery from the load or charger, to prevent damage. Each cell is monitored for temperature and excess current drain and again the battery is disconnected from the load if these limits are exceeded. The BMS also monitors the state of charge for each of the four cells and automatically balances their voltages during the recharge cycle to bring all cells to full charge at the same time. This balancing ensures a safe full charge and long battery life. Based on these features Lithium Iron Phosphate Batteries (LFP) are very safe and reliable. Since 2015 BSLBATT Lithium has been monitoring hundreds of Lithium Battery Systems installed in RV’s in the field, without any reported Lithium Battery or Charger failures.

What is the number one question people have when thinking of converting their 4×4 or Sprinter for the first time?

Mr. Li: “I’d say the number one question is ‘how do I make this vehicle the dream off grid vehicle?’ The second most common question is ‘are lithium batteries worth the cost to upgrade from lead acid batteries?’ What we’re finding is that the vast majority of people are deciding that lithium batteries are worth the cost to upgrade because they enable people to live much more independent and adventurous lifestyles, free of unnecessary constraints.”

Why do you see RV and off-road owners making the switch to lithium batteries?

Mr. Li: “They just work better in all conditions and climates, hot or cold. They last far longer than lead-acid batteries. AGM batteries only last about 500 charge cycles versus 5,000 to 7,000 for lithium batteries. Unlike lithium batteries, AGM batteries can also only use up to 50% of their capacity before risking permanent damage. A 300 amp hour AGM system will only supply 150 amp-hours before requiring a charge. In freezing temperatures, usable AGM amp hours are halved again. All of these factors severely limit off-road vehicle owners’ freedom, independence, and overall lifestyle, which is why so many are switching to lithium.”

Why did you choose BSLBATT lithium as a partner?

Mr. Li: “They make exceptional, cutting edge products and offer consistently superior customer service. They’re also focused on providing reliable energy systems that empower adventurers with greater independence and comfort, which directly aligns with our mission and work.”

You are using the B-LFP12-100 in your upgrades. What is it about the B-LFP12-100-LT that made it the choice for Agile?

Mr. Li: “Most lithium batteries don’t work in very cold temperatures, but BSLBATT ensures that winter camping excursions won’t be put on ice as a result of the batteries. BSLBATT’s B-LFP12-100-LT batteries (low temperature) work really well below freezing and are capable of safely charging & discharge at -4° Fahrenheit. Cold weather operation is made possible by the B-LFP12-100-LT battery’s state-of-the-art non-parasitic battery heating system. An internal heating system eliminates the need for battery blankets, which often require the consumption of energy directly from the battery. Since the B-LFP12-100-LT battery’s warmer only accepts power from an external source (e.g., solar, shore, engine battery via the alternator), it will never consume energy from the battery itself to charge, which therefore frees up more energy for use by the vehicle owner.”

How important is the environmental impact of lithium batteries to your customers?

Mr. Li: “Extremely important. That’s one of the things we love most about our customers. The thing about people who enjoy adventuring outdoors is that they really want to take care of the environment when they’re out there. From basic things like picking up trash at campgrounds and leaving them as they were found to the long-term environmental impact of their energy system, they have the utmost respect for nature. The fact that BSLBATT energy storage systems will last at least two to three times as long as lead-acid batteries and therefore won’t have to be replaced as often is definitely important to them.”

Lithium batteries are slowly gaining ground when it comes to consumers choosing it over lead-acid. What have you seen or heard in the marketplace or from customers to support this change?

Mr. Li: “Everyone, including all of the people posting in online forums, is talking about using lithium batteries in these vehicles. The main topic of discussion is whether lithium batteries are worth the additional upfront cost. Lithium batteries are a huge driver for our business, as people are wanting to upgrade their kits with us to incorporate lithium batteries. People have been primarily motivated to get lithium batteries due to the significantly longer battery lifespan and their ability to be discharged to almost 100%. Lithium batteries also weigh far less and take up much less vehicle space.

How Fast Will My Lithium Battery recharge?

The answer depends on the total Amp Hour (AH) rating of your Lithium Battery pack and the current output rating of your charger. For example, a 100 Ah Lithium Battery connected to a BSLBATT Lithium BSWJ (60-Amp) Charger would complete the recharge time as follows (100 Amp Hour Battery divided by 60 Amps per hour recharge rate) equals 1.7 hours. However, as the state of charge nears completion the charge current is gradually reduced, so the real total time would be around two hours. Under these same conditions, a Lead/Acid Battery would require approximately 6 to 8 hours, more or less, to reach full charge.

How Should I Store My RV Lithium Battery During the Winter?

Another advantage of Lithium Iron Phosphate Batteries is that they do not require a trickle charge during long periods of storage. In fact, disconnecting the charger during winter storage or long term inactivity and allowing the battery to rest is actually beneficial and will improve long term battery life. Before putting your RV into winter storage, simply connect it to 120 VAC power for up to 10 hours for large battery packs and fully charge the battery, then remove AC power and hit the battery disconnect switch. In the spring it will be ready to accept a full charge before your first camping trip. Lithium Batteries have a very low self-discharge rate and only lose 2 to 4% of their charge per month.