When it comes to modern energy storage, lithium batteries are the clear leader for performance, lifespan, and charging efficiency. Whether you’re powering an RV, boat, off-grid cabin, or renewable-energy system, understanding how lithium batteries recharge will help you get the most out of your investment.
This article breaks down the fundamentals of lithium battery chemistry, charge profiles, and voltage behavior. If you’re looking for information specific to Battle Born LiFePO4 batteries, check out our companion guide:
Charging Battle Born LiFePO4 Batteries
Before you go recharging lithium batteries, it’s essential to know their chemistry type. All batteries are basically controlled chemical processes, and the type changes the charging profiles and requirements.
All lithium batteries work by moving lithium ions between a positive cathode and a negative anode through an electrolyte. When you discharge a battery, the ions flow from the anode to the cathode; when you recharge, the ions flow back in the opposite direction.
Different lithium chemistries use unique materials that determine voltage, safety, and performance. The most common types include:
You can see a detailed breakdown of these chemistries, including energy density and voltage comparisons, in Dragonfly Energy’s Guide to Lithium Battery Types.
Unlike older lead-acid designs, lithium batteries charge in a simple two-stage process rather than three. Here’s how it works:
Lithium batteries do not require a float charge to finish charging, unlike lead-acid, maintaining them at full voltage for long periods can actually shorten their lifespan. Most modern lithium chargers instead stop automatically or maintain a very light top-off voltage around 13.4–13.6V for a 12-volt LiFePO₄ system.
Now, let’s take a look at the actual voltages these batteries produce.
Each lithium chemistry has its own voltage range. The following chart provides general reference values (values are per cell; multiply by the number of cells in your pack for system voltage).
| Chemistry | Nominal Voltage | Full Charge Voltage | Recommended Cutoff | Float / Storage |
|---|---|---|---|---|
| LiFePO₄ | 3.2 V | 3.6 – 3.65 V | 2.5 V | 3.3 V |
| NMC / LCO | 3.6 – 3.7 V | 4.1 – 4.2 V | 3.0 V | 3.7 V |
| LTO | 2.4 V | 2.8 V | 1.5 V | 2.5 V |
You may hear that batteries are 12V, 48V, or even 300V+ for electric cars. But you need to understand that those voltages are just multiple cells connected. The chemistry of the battery only produces a few volts, so we use lots of cells connected to boost the voltage.
A typical “12-volt” lithium battery is a 4-cell pack in series (4 × 3.2 V = 12.8 V nominal). Systems are often expanded into 24 V or 48 V configurations for larger off-grid or marine installations.
When charging batteries either at the pack or individual cell level, it’s critical that the cell voltages stay within the limits of the battery chemistry. This is why battery management systems are critical in lithium batteries.
One of the greatest advantages of modern lithium batteries is their ability to work seamlessly with almost any energy source. Whether your system pulls from solar, wind, a vehicle alternator, or even the electrical grid, your battery acts as the energy buffer between power production and consumption.
When your power source is active, say, your solar panels are generating electricity, the energy flows first to the battery, which stores what’s not immediately used by your system’s loads. If your energy demands exceed what your panels or alternator can supply, the battery supplements the difference, delivering steady power without interruption.
When the battery reaches full charge, your charge controller or inverter-charger simply stops feeding energy into it, preventing overcharging. As soon as a new demand appears (a fan turns on, a light is switched on), energy again flows through the battery to power your system and if the source is still available, the charge controller will use whatever’s available (say solar power) to feed the device.
This dynamic interaction is what makes batteries essential in non-continuous power generation systems, they stabilize voltage, fill in production gaps, and store excess energy for later use.
Let’s look at how this works with the most common charging sources used by Battle Born customers.
Solar panels are one of the most popular ways to recharge lithium batteries, especially in RVs, boats, and off-grid properties. Since sunlight intensity varies constantly, the output from solar panels fluctuates.
A solar charge controller, either MPPT (Maximum Power Point Tracking) or PWM (Pulse Width Modulation)—manages this variable energy and converts it into a stable voltage and current suitable for charging lithium batteries.
MPPT controllers are preferred for lithium systems because they maximize efficiency by adjusting voltage dynamically to extract the most power from the solar array. Once the battery reaches its target voltage (usually 14.2–14.6V for 12V systems), the controller tapers the current and eventually stops charging.
👉 Learn more in our Solar Charging Basics for RV and Off-Grid Systems guide.
In RVs, vans, and marine systems, the vehicle’s engine alternator is a convenient source of DC power. However, alternators are designed for starting batteries, not deep-cycle lithium systems. Connecting them directly can cause high current surges or voltage mismatches.
That’s where DC-to-DC chargers (also called battery-to-battery chargers) come in. These devices take power from the vehicle’s alternator, regulate it to the precise voltage and current your lithium bank needs, and safely recharge your house batteries while driving.
The DC-to-DC charger protects both systems—it prevents alternator overload, ensures proper charge profiles, and even allows different chemistries (lead-acid starter and lithium house) to coexist without issue.
Its also possible to use the engine as a major charging source by adding a second alternator dedicated to charging the batteries. These systems use dedicated alternator controllers like our Wakespeed unit to maximize charge. This is a great choice for those who drive a lot and can even be the primary power source. Popular among van campers and marine users.
When you’re connected to the grid—whether in a marina, RV park, or at home—you can charge your lithium batteries using AC power through an inverter-charger or a dedicated AC-to-DC converter.
The inverter-charger converts AC electricity to DC for charging, following the voltage and current limits specified for lithium chemistry. Once the batteries are full, it automatically transitions to power pass-through mode, allowing the grid to directly run your onboard devices while maintaining battery charge.
👉 Explore our compatible inverter-chargers and system components.
Generators remain a reliable way to recharge lithium batteries during low-sunlight conditions or high power demand. Generators can run on gasoline, diesel or propane and most RV and off-grid systems route generator output through an inverter-charger, which automatically converts AC power to the correct DC charging voltage.
Because lithium batteries can accept high charge currents, generators paired with smart chargers can recharge your system much faster than when using lead-acid batteries, often cutting runtime in half. Because our lithium does not need to be recharged to 100% each time, it means less noise, less fuel, and more efficient energy use when you need a boost.
For long-term off-grid setups, wind turbines and micro-hydro generators offer renewable charging even when the sun isn’t shining. Like solar, these sources produce variable DC power that must be regulated before it reaches your batteries.
Specialized wind or hydro charge controllers perform this regulation, converting fluctuating input voltages into a stable, lithium-compatible charge profile. When the batteries are full, the controller either stops charging or diverts excess energy to a dump load or diversion resistor (if required by the generator unit), preventing overcharging and maintaining system balance.
Paired with a solar array, these systems can provide nearly continuous renewable generation year-round, especially valuable for remote or marine installations.
Essentially, if the source can provide the right charge profile, it can recharge a lithium battery safely and efficiently.
👉 Explore our related guides:
To maximize the lifespan of your lithium battery bank:
Following these steps can easily extend your lithium battery life to 5,000–10,000 cycles or more.
If you’ve ever used traditional lead-acid batteries, you know that charging them can be slow, inefficient, and maintenance-heavy. While lead-acid technology has been around for over a century, lithium has redefined what’s possible in both performance and simplicity.
Lead-acid batteries are inherently inefficient, often losing 15–25% of the energy you put into them as heat or chemical loss. Lithium batteries, by contrast, are over 95% efficient, meaning nearly all the energy from your charger or solar array is stored for later use.
That efficiency not only saves power, but it also shortens recharge time dramatically. A lithium battery can typically recharge in half the time of a comparable lead-acid bank, even when using the same charger.
A lead-acid battery’s voltage rises quickly during charging and then tapers slowly through long “absorption” and “float” phases. These extended stages are necessary to prevent gassing and sulfation, but waste time and energy. Without getting through the absorption cycle, each charge lead-acid battery will be damaged.
Lithium batteries, however, don’t require this and can be stopped charging at any point without damage, far better for intermittent charge sources. The lack of absorption is another reason the batteries charge so much faster.
Even after a full recharge, lead-acid batteries shouldn’t be discharged below about 50% of their capacity to prevent damage. Lithium batteries, on the other hand, can safely use nearly 100% of their stored energy and then recharge without degradation.
This means fewer charging cycles, less maintenance, and more usable power from the same physical footprint.
Lead-acid batteries require regular monitoring of fluid levels, equalization charging, and venting. Overcharging can cause outgassing and corrosion, while undercharging leads to sulfation—both shorten battery life.
Lithium batteries eliminate those issues entirely. There’s no watering, no equalization, and no venting. A built-in Battery Management System (BMS) handles voltage balancing and cell protection automatically, extending lifespan to 3,000–5,000 cycles or more, far beyond what lead-acid can deliver.
For RV, marine, or off-grid applications, the difference is dramatic. Faster recharging means shorter generator run times, quicker solar recovery after cloudy days, and less downtime between adventures. And since lithium holds its voltage under load, your appliances and inverters perform better all the way to empty.
Our customers who have switched will happily tell you that it’s a night a day usage difference with lithium as the primary energy storage.
Q: Can I recharge a lithium battery with a lead-acid charger?
A: Sometimes, but only if it can be set to the correct voltage and has no equalization mode. Always verify compatibility with your manufacturer’s specs.
Q: What voltage should I recharge a 12-volt lithium battery to?
A: Most 12-volt lithium systems reach full charge around 14.2–14.6 V, depending on chemistry.
Q: Why did my lithium battery stop charging early?
A: Your charger may not be providing the correct voltage, or your Battery Management System (BMS) may have limited charging to prevent over-voltage or temperature issues.
Q: Do lithium batteries need to be fully charged every time?
A: No. In fact, partial recharges are fine for long-term life.
Q: How often should I recharge my lithium battery?
A: Recharge whenever the voltage drops near the lower cutoff for your devices, generally around 10–20% remaining capacity. Lithium batteries hold charge well during storage, so letting them sit for even 6 months to a year is usually okay.
Understanding lithium battery recharge behavior is key to designing a reliable, long-lasting power system. Every lithium chemistry follows the same core principles: precise voltage control, efficient ion transfer, and minimal loss. With the right charger or controller, you can safely and quickly recharge your batteries from virtually any energy source.
When you’re ready to move from theory to practice, explore how these principles apply to Battle Born’s LiFePO₄ batteries—the industry benchmark for performance and reliability:
👉 Charging Battle Born LiFePO4 Batteries
👉 Shop Battle Born Batteries
With a solid understanding of how lithium charging works, you’ll have the confidence to build, maintain, and enjoy your power system—no matter where your adventures take you.
We know that building or upgrading an electrical system can be overwhelming, so we’re here to help. Our Reno, Nevada-based sales and customer service team is standing by at (855) 292-2831 to take your questions!
Also, join us on Facebook, Instagram, and YouTube to learn more about how lithium battery systems can power your lifestyle, see how others have built their systems, and gain the confidence to get out there and stay out there.
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35 thoughts on “Charging Lithium Batteries: The Basics”
I don’t understand the following statement that I copied from your Charging Lithium Batteries: The Basics, To Float or Not to Float section. “However, if you have an RV with a battery bank plugged into shore, you should avoid running your appliances off the battery bank. You will want to run your chargers to power your coach and be able to float because it helps keep batteries fully charged while running your appliances from shore power through the charger. Although the batteries themselves don’t need floating in terms of a charge cycle, the float is useful when plugged into shore and don’t want to drain your batteries while using your system.”
I just set up and tested my system including a shore power charger. I have all chargers (+) cables going to a busbar connected to my batteries through a switch. The load fuse box is also connected to the (+) busbar. Does this system satisfy the correct charging condition you describe in the statement above? If not, how would I correct it? Thanks.
Hi Michi, I will look into revising the verbiage in the blog post as I understand it is confusing. Our sales team recommends that unless you are utilizing a cutoff switch, you do not have a choice to where the 12v comes from. If you have a Fixed Voltage Output converter, it would be best to utilize a disconnect switch to remove the batteries from the circuit to allow them to rest. If you have a multistage charger or converter, you are able to keep the batteries in the circuit because they will be able to rest at an acceptable voltage in the final stage of the charge.
If you have any additional questions please give our sales and tech team a call at 855-292-2831 and they would be happy to assist with any troubleshooting. Thanks for reaching out!
I purchased two BattleBorn 12v 100ah lithium batteries to replace one 12v 100ah wet cell battery in my trailer. Can I charge the new batteries from the same system used to charge the original battery?
I plan to hook up the new batteries in parallel to get 12v.
Hi Jack, our batteries are drop in replacements for lead acid batteries. If you have any additional questions please give our sales and tech team a call at 855-292-2831.
Can you elaborate on this: “unless you are utilizing a cutoff switch, you do not have a choice to where the 12v comes from. If you have a Fixed Voltage Output converter, it would be best to utilize a disconnect switch to remove the batteries from the circuit to allow them to rest. If you have a multistage charger or converter, you are able to keep the batteries in the circuit because they will be able to rest at an acceptable voltage in the final stage of the charge.”
I’m sorry to beat a dead horse as this has already been asked, but I’m not clear what this statement means. Maybe a simple circuit diagram would be helpful. Thanks!!
Hi Russ, thanks for reaching out. We’ll look into creating a simple circuit diagram soon but in the meantime you can check our YouTube channel out here for any additional assistance: https://www.youtube.com/channel/UCu9mOYKj4r5-CVxP5evPGrA
I’m currently running 2 x 120 AH lithium batteries rigged in series for a 24 volt trolling motor, can I charge via a 40AMP 12 volt lithium charger if I rig the batteries in parallel via some Anderson plugs ?, will this put the batteries out of balance & if I stayed with this system can the batteries be re balanced or what charging system would you suggest ?
Thanks in advance
Good morning Simon! Thank you very much for reaching out. You could put the batteries in parallel to charge them with a 12v charger, but this requires a bit more effort that it may be worth. Our team recommends using an isolated 12v charger for each battery, or a multibank charger. These options will allow you to charge the batteries while they are still connected in series. If you need any more technical assistance, please give us a call at 855-292-2831. Thank you again and have a great rest of your morning!
i’m installing a renogy battery monitor. what value to set for the battleborn’s lowest state of discharge? 14.4 is 100%, but what is the lowest number?
Hi there! We’d love more information about your system, so please give our sales and tech team a call at 855-292-2831 for us to answer any additional questions. Thanks again for reaching out and have a great rest of your morning!
We set up our sailboat with a house bank of four battleborn 100Ah 12V batteries. We also have a typical AGM starter battery. We want to keep the house and starter charged via our Balmar alternator, solar MPPT charge controller, and 120V shore power. What’s the simplest way to keep the battleborn’s happy and keep the starter battery topped up and ready?
Hi Denise! We have recently published an article that could help with your system: https://battlebornbatteries.com/solar-battery-charger-for-boats/ and if you have any additional questions, please give our sales and tech team a call at 855-292-2831 and they can assist with further detail.
I have a lithium battery and like to know why it doesn’t charge up to its maximum. I started charging at 12:00pm and its almost 5:00pm and it’s on dot three and it has five dots. The indicator max’s out at five dots. Thank you for your time with my message
Hi Mark, thanks for reaching out. Our sales and tech team would love to learn a bit more about your system and its charging methods, so if you could please give them a call at 855-292-2831 they would be more than happy to assist.
Hello. I’ve added Battleborn batteries to my fishing boat. I run 2 for the trolling motor and 1 as a house battery. I charge them just fine with the Minnkota precision on board charger set on the AGM mode. My question is can all 3 of my Battleborn lithium batteries also be charged with the onboard Minnkota alternator charger MK3DC? The MK3DC redirects the charge from the starting battery and sends that extra amps to the 3 bank charger, but only when the starting battery reaches 13.6V. Minnkota’s spec sheet states it is not optimized for lifepo4, but am unsure if it is compatible or if it can damage these types of batteries?
Hey Cliff! The Minnkota Precision charger will work great for that setup. It will not hurt the batteries and you will get a nice trickle charge from it. It will not be able to top the batteries off but will work. As far as the MK-3-DC it is a 12,24, or 36 volt dc to dc charger. They don’t list the voltages but customers have reported that they work well. Each output is 12amps per bank and will charge from the starter battery.
Greetings BattleBorn,
I’ve been using your 100A lithium batteries (x4 connected to a 1350W Solar Array) in a 42′ fifth wheel for about 3 years now (we full-time). They work great! We bulk charge and absorb charge at your recommended settings.
Can you help with the following 2 questions.
1) Do you have charts (like the wet cell’s do) that show the percent drain of the batteries as the voltage drops? Are they the same as wet cells?
2) Should BattleBorn batteries be set to drop out at 10.5V like a regular wet cell or can they go lower without inflicting damage (to the batteries or any connected equipment)?
Hi there! Thanks for reaching out and we are so glad to hear that the batteries are working flawlessly in your fifth wheel. As for a state of charge chart, here is a link: https://battlebornbatteries.com/wp-content/uploads/2021/08/MicrosoftTeams-image-89.jpg
The Battle Born BMS will open at 10v to prevent further discharge. At 10v, you would have received 100ah out of the battery. We recommend an inverter Low Voltage Disconnect at 11.5v. If you have any questions about your system, you can always give our team a call at 855-292-2831. Thanks again!
I own a Mercedes Benz diesel sprinter, Airstream Interstate 19, which currently has two AGM house batteries. I have a handicapped son and I primarily used my vehicle for travel and not for camping or boon docking. I would like to replace the two AGM batteries with two Battle Born lithium batteries. Would two Battle Born lithium batteries drop in without having to purchase additional equipment to make the change over from AGM batteries to lithium batteries? My Airstream Interstate 19 comes with a 1,000 watt inverter. Will the system I have, 1) charge two lithium batteries; 2) will the lithium batteries harm my Mercedes Benz alternator; and 3) will my inverter and vehicle alternator “fully” charge two lithium batteries? In other words are lithium batteries merely a drop in swap of batteries from AGM to lithium or is it necessary to add other equipment to make the swap?
Thank you,
David Hudson
Hi David! Thank you for reaching out. What is the make and model of your converter? Do you also have anything between your alternator and battery bank? Our sales and tech team would be more than happy to assist and answer these questions if you give them a call at 855-292-2831 and have the answers to those questions ready.
I have the BB 12v 100Ah battery in my camper. I know that the WFCO shore power unit cannot charge lithium batteries fully, so I’ve used my Victron Blue Smart Charge (5 amp) and solar array to occasionally attempt do that. While the readout from the BSC may indicate that the battery is fully charge, the battery voltage at that point is never above 13.36v. Per the Li SOC table , that indicates that the battery is somewhere between 90 and 99% charged. This is also the case when using the solar array; the controller (Renogy PWM type) on its Li setting indicates fully charged, but the measured voltage is the same as with the BSC, 13.36v.
The battery is relatively new – May of this year. What could be the reason(s) that I can’t get the battery to 100% – 13.6v?
Hi Charlie, thanks for your patience. Depending on how many watts of solar you have, it is possible that there is not enough of a solar window to fully replenish the battery bank. The 5 amp charger is more of a trickle and would take 25 hours to charge the battery from 0 to 100%. Please give us a call at 855-292-2831 to discuss.
Hi.
I’ve had a couple of your 100ah batteries for over 10 months while I build out my van. I needed the batteries back then for dry-fitting, and have never hooked them up. I have a Battery Tender Junior – should I connect the batteries to the battery tender occasionally, until I’m ready to connect the batteries in my van? May be another year before I’m ready to connect them in the van.
Also, is the Arizona summer heat detrimental to the batteries if I leave them sitting in the incomplete van during the 130deg+ summer months, or do I need to remove them from the van?
Thanks!
Hi there, great question. The storage temperature range is -10°F to 140°F (-23°C to 60°C). We recommend bringing the Battle Born Batteries to a 100% charge and then disconnecting them completely for storage. After six months in storage, your batteries will remain 75 – 80% charged. On the high end of the temperature range, the batteries will shut down once 135°F is reached inside your van. If you have any additional questions, please feel free to reach out to our technical sales team at 855-292-2831.
I have a Bogart with no battery monitor..this are the charge parameters by jumpers below what would be best with a single 100 amp Lithium and can I top them off totally by my stand alone lithium charger to get them to 100% once in a while…currently JUST using the stand alone but have the extra controller and solar panels already on roof 🙂
Charger Parameters of Bogart SC 2030
Liquid electrolyte 12V 14.7V 13.2V
Gel or AGM 12V 14.2V 13.2V
Thanks for any help as to which is best
I have a new travel trailer with a WFCO 8955LIS converter. Also have a PD4655LIV converter I could use to swap out the WFCO converter.
Which converter would be best at maintaining my four new 100ah heated BB batteries, wired in parallel, over the long term?
If neither, which converter would you recommend for my WFCO power center?
Thank you.
Hi, I have a LifePo4 12v 100ah Lithium Battery can I use a Noma100W solar panel with 8.5amp controller to charge this battery? Your info says to charge with a 14.4 volt controller…the Noma controller says it is 14.2v Thank you!
Some sellers recommend that only 4-12v 100 amp hr lithium batteries be charged in parallel connection, why would 6 in parallel be a problem?
Hi Lee! Here are our recommendations for the amount of batteries that can be wired in parallel vs. the amount that can be wired in series. There is no limit to how many batteries you can wire in parallel. The more batteries you add in a parallel circuit, the more capacity and longer runtime you will have available. The limit on how many batteries you can wire in series typically depends on the battery and manufacturer. For example, Battle Born allows up to four of their lithium batteries to be wired in series to create a 48-volt system. Always check with your battery manufacturer to ensure you do not exceed their recommended limit of batteries in series.
I am confused by the shore charging paragraphs. In the first, you say a 100amphr battery can be charged in 2 hours by a 50 amp Charger. In the next, you describe a system of batteries which take 5 hours to charge.
You then state that batteries can be charged faster but shouldn’t. Faster than what? Example #1, or Example #2? I am planning on traveling for work and living out of my minivan, and need power for my 30L 12v fridge. My plan is to need to charge my 100amp battery every three days, which I could do in an hour w my generator. Running a generator for 5 hours every 3 days to make my fridge run seems a bit unappealing.
Hi Angela. If you have one 100Ah battery and a 100A charger, then it will take you one hour to charge your battery. If you have a 50A charger, then it will take you two hours to charge your 100Ah battery. Our recommended charge rate is 50 amps per 100 Ah battery in your system. We don’t recommend you exceed this charge rate as it can lead to a shortened battery cycle life.
Pardon my lack of knowledge, but what does it mean when you say “The batteries naturally float at 13.6V”?
What exactly is happening to the batteries when it’s “floating”?
The lithium battery charger can behave in several different ways during the charging process. First, the charger can steadily increase its voltage in order to keep the current flow constant. This is the first stage of the charging process – typically called the “bulk” charging stage. During this stage, the charger adjusts its applied voltage to deliver the maximum current to the battery.
Once the bulk voltage is reached, the charger enters a second stage, called the “absorption” charging stage. During absorption, the charger applies a constant voltage, called the “absorption voltage.” As the battery’s open-circuit voltage approaches the absorption voltage, the current flow steadily decreases down to zero.
At this point, the battery is fully charged. However, a lead-acid battery will rapidly lose charge when the charger is disconnected. So, instead of turning off, the battery charger enters a third stage called the “float” stage, in which the charger drops to a lower voltage and holds at that voltage. The point of this stage is to keep the battery topped off, and account for the fact that lead-acid batteries tend to drain, even when there is no load connected.
While lithium batteries technically don’t need to be floated, a good majority of the devices out there still have a float charge mode. The batteries naturally float at 13.6V but reaching 14.6V is ideal and needs to happen in order to engage its balancing mechanisms.
I have 2 BB 100ah batteries I purchased awhile ago for my tow behind trailer – they work great. Charging while traveling has not been something I have needed so I have not installed a dc to dc charger. I have solar on the trailer and the panels with the MPPT controller charge/maintain the charge when traveling. The batteries have been fully charged for almost all of our trips when we head out or back home so to date I have not experienced any issues with the alternator being stressed from charging the trailer batteries.
I believe that the standard 7 pin plug will not allow sufficient power from the alternator to really damage it due to the length of the wire run and the gauge used. I think I read on your site sometime ago that if you have 2 or fewer batteries, not to worry but I cannot find this now.
Can you confirm that I am ok as is or should put in an isolator or some other device? I have a 2019 RAM 1500 with the 5.7 hemi.
Hi Bob! When using your alternator to charge your BB house batteries, we recommend using a DC to DC charger in between to help protect your alternator.