In part one we discussed the difference between lead-acid, AGM, and Lithium batteries. Since then I have talked with our technical department and asked “how do you know if the lithium battery you are considering is good quality? They indicated that “lithium” is the new hot button in the RV industry and they are flying off the shelves. Many “opportunistic” companies are doing a “lick & stick” (his words exactly) by purchasing cheap overseas lithium and putting their sticker name on it. Many of these have prismatic and palmer cells that can not withstand the vibration and bouncing the typical RV encounters as well as temperature changes. This creates connectivity issues and produces thermal events.
Quality lithium batteries use cylindrical cells for the internal pack and protect them with molded ribs instead of foam filler. Also, the connection between these cells is best with mechanical connection rather than solder which is cheaper but is not as stable.
So how do you know? First, look for the UL listing and the file number. Then ask for an exploded view and description of the interior of the battery! If they can’t provide it, chances are the components are sub-par!
Then I asked; “What else should we look for in Lithium Batteries for an RV?” The answer was a good Battery Management System or BMS built into the battery. A BMS monitors the cells within the battery and keeps them from operating in an unsafe condition due to overcharging or undercharging. It can detect any shorts in the connections and balance the charge in each individual cell. If it does find an issue, it will shut the battery down before any damage can occur. This is especially important if your charger has a bulk charge stage or if you’re trying to get that last bit of sunlight in your solar panel charging system.
Temperature Is Important
The BMS will also monitor the temperature to make sure the battery either shuts down during extreme high and low temperatures or controls fans or heaters that could be part of the system. Extreme high temperatures can cause thermal runaway and charging a Lithium Battery at below-freezing temperatures will ruin the battery. The BMS will shut down the battery if it is not equipped with a cooling fan or heater. A quality Lithium Battery will either have an internal heater or heat pad/blanket that the BMS will activate when needed.
Now that we know what to look for in a quality Lithium Battery, there is more information you need to consider before jumping into the Lithium world! In Part 1 we talked about the WFCO converter that was used in the RV and how it only provided a 13.6-volt charge however you need to research what converter/charger or inverter/charger you have and how it operates. Most Lithium Batteries want 14.6-volts for charging and can be charged much faster than the typical lead-acid batteries. If your converter only provides 13.6-volts it will take longer to charge and will not charge 100% so you lose about 35% of what you paid for. Even worse, if you have a multi-stage charger it will start the bulk charge at 16-volts to break up sulfation in the lead-acid battery and then go to a float and equalizing charge. 16-volts will ruin a Lithium Battery unless it has a BMS in which case it will shut down and won’t charge!
One option is to install an upgrade to your converter such as the Progressive Dynamics 4655CSV model. This runs approximately $250 but is well worth it to get 100% out of your Lithium Battery.
If your converter, inverter, or solar charger is not putting out 14.6-volts I would recommend you consider upgrading the charger, lead-acid, or AGM. I did speak to a representative at Magnatek which is owned by Parallel Power Supply and they are using a stand-alone converter that puts out 13.8-volts and recommending it for use with Lithium. If you have a larger diesel pusher model and/or a residential refrigerator chances are you have a larger inverter that is also a battery charger and need to verify what voltage it is providing. Most newer models have a setting for Lithium.
DC To DC Charger
If your rig has the capability to provide a charge from the engine battery whether it’s a tow vehicle pulling a trailer with the 7-pin connection or a motorhome through the Battery Isolation Management solenoid (BIM) your alternator could potentially provide over 225 amps such as the case with a Mercedes model. This would require a DC to DC Charger that will regulate the amps. Battery Born recommends the Victron and Mike Sokol of The No Shock Zone recommends the Redarc model.
The Advantage Of Lithium Batteries
The biggest advantage of Lithium Batteries in my opinion is they do not sulfate and do not require much maintenance. Yes, the cost can be 5 times as much, however, the average lead-acid battery lasts about 2-3 years unless it is maintained religiously then it could last up to 4-5 years. The average Lithium Battery will last 8-10 years, so if you plan to keep your rig for more than 5 years, it will most likely cost about the same, however, you get all the other advantages.
A Lithium Battery can be drawn down to almost 100% vs a lead-acid battery at only about 50% and it will charge up about 5 times as fast so you get longer battery usage when dry camping and faster recharging so you don’t have to run the generator all day or worry about only getting a few hours of sun with a solar charging system.
Lithium Batteries are about ½ the weight of lead-acid batteries and you get the same amp hours out of one 100-amp hour Lithium vs two lead-acid batteries. So the Lithium Battery is lighter and takes up ½ the room in a compartment or on the tongue of your trailer.
Once you review all the information and what type of charging system you have, you can now decide if Lithium is the right choice for you and worth the money.
About the author: Dave Solberg: Managing Editor, RV Repair Club
For the last 25 years, Dave has conducted RV maintenance and safety seminars, developed dealer and owner training programs, written RV safety and handyman articles authored an RV handbook reference guide, and logged over 100,000 miles on the road in an RV.
RV Repair Club is your go-to online resource for enthusiasts who want quality RV maintenance, repair, and upgrade information – a community where passionate RVers can come together to gather knowledge and share their experiences.
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