- Reduce Depth of Discharge
- Use a Battery Management System
- Select the Right Lithium Battery
- Disconnect When Not in Use
- Charge Regularly
- Avoid Heat Exposure
- Clean Battery Terminals
- Consider Battery Capacity
- Balance Voltages
- Watch Charging Voltages
- Watch Discharge Voltages
- Consider Temperature Limits
- Address Any Faults
- Consider Replacement Batteries
Lithium batteries have become incredibly popular for RVs and campers. Compared to traditional lead-acid batteries, lithium batteries are lighter, store more power, and have a much longer lifespan. But like any battery, lithium batteries require proper care and maintenance to get the most out of them. Follow these practical tips to extend the cycle life of your RV’s lithium batteries.
Reduce Depth of Discharge
The depth of discharge (DoD) refers to how much capacity is drained from a fully charged battery before it is recharged again. The deeper a battery is discharged on each cycle, the fewer total cycles it will last before needing replacement. Lithium batteries last longer when discharged to a shallower depth on each cycle.
For example, if you limit the DoD to 50% by recharging at 50% remaining capacity, a lithium battery could last for 3,000-5,000 cycles. But if you regularly drain down to 20% capacity before recharging, the lifespan drops to 1,000-2,000 cycles.
Aim to keep the DoD between 20-50% for optimal longevity. Monitor your battery voltage to avoid over-discharging. Most lithium batteries should not go below 12V or 3V per cell. Going too low risks permanent damage.
I try to recharge my RV lithium battery when it gets down around 50-60%. This means I’m only using about half the available energy before topping it back off. I could push it lower, but limiting the depth of discharge has given me over 4 years of reliable service so far. A little forethought goes a long way!
Use a Battery Management System
A battery management system (BMS) is an electronic module that monitors and protects lithium batteries from operating outside safe parameters. Quality BMS units prevent:
- Over-discharging cells
- Over-charging and over-voltage
- Extreme temperatures
- Short circuits
- Cell imbalances
Protecting your lithium battery from these hazards is crucial to maximize longevity. A BMS regulates the charger, safely balances voltage between cells, and shuts off discharge at a preset low-voltage cutoff.
The Victron Smart BMS is an excellent choice I’ve installed in my own RV. It’s compatible with Victron inverters and solar charge controllers, but can also work standalone. The Victron Connect app lets me check battery stats and customize settings easily from my phone. After 2 years of reliable service, I’d absolutely recommend it.
If your RV didn’t come with a built-in BMS, adding an aftermarket one is highly recommended. It’s a small investment that pays off by extending the usable service life of your expensive lithium battery bank.
Select the Right Lithium Battery
Not all lithium batteries are created equal. When shopping for an RV lithium battery, there are a few key factors to consider:
- Battery chemistry – Lithium iron phosphate (LiFePO4) is the safest and most long-lasting choice. Other types like lithium cobalt oxide (LiCoO2) can be less stable.
- Reputable brand – Go with an established battery manufacturer like Battle Born Batteries, Renogy, or Weize rather than a no-name import. Quality matters.
- Temperature rating – Opt for batteries rated for wide temperature operation, at least -4°F to 140°F.
- BMS and certification – Choose a battery that includes a BMS and safety certification from FM/UL.
- Capacity – Make sure to get enough capacity to run your RV essentials between recharges. 100-300 Ah is typical for RV applications.
I chose Battle Born LiFePO4 batteries for my RV and have been thrilled with their performance. With a wide -4°F to 140°F operating range, built-in BMS, and 10-year warranty, they tick all the boxes for quality and longevity. The 100 Ah capacity provides all the power I need off-grid camping for several days.
Choosing the right lithium battery from the start prevents headaches down the road. Do your homework to find a battery that meets your needs and will go the distance.
Disconnect When Not in Use
When your RV sits unused for weeks or months at a time, the lithium batteries can still drain slowly. Parasitic loads from alarm systems, automatic vent fans, and other devices add up over time. One simple way to extend battery life is to disconnect the batteries when not in use.
Installing a battery disconnect switch makes this quick and easy. I mounted mine in an exterior compartment for convenience. When I’m ready to hit the road, I just flip the switch to reconnect the batteries.
Before storing your RV, give the lithium batteries a partial recharge to about 30-50% state of charge. This reduces strain on the cells compared to leaving them fully charged or fully drained for months.
By disconnecting my RV batteries during long-term storage, I can be sure they stay fresh and ready for the next adventure. It really does make a difference in battery health over time.
Charge Regularly
For maximum longevity, lithium batteries should be charged regularly rather than allowing them to remain partially discharged for long periods. Try to recharge lithium batteries at least once per month, even when not in use.
One memory trick is to charge them up around the same time you pay your monthly bills. Set a reminder on your calendar so you don’t forget. This helps prevent deterioration from chronic undervoltage.
If your RV will be stored at high temperatures over 90°F, charge even more frequently – at least every 2 weeks. Heat accelerates self-discharge rates in lithium batteries. Keep them topped off to compensate.
During winter storage, pay special attention to battery temperature. If they drop below freezing 0°C/32°F, bring the batteries indoors or onto a heated RV pad to warm up before charging. Never charge a frozen lithium battery!
By making battery maintenance a habit, you’ll ensure your lithium batteries stay healthy andoptimized for maximum capacity. Think of it like checking the air pressure in your tires.
Avoid Heat Exposure
Lithium batteries thrive in moderate temperatures but suffer damage when exposed to sustained heat over 120°F. The hot summer sun can quickly overheat batteries stored in your RV.
If possible, store your RV in a shaded or covered area during hot weather. Using reflective window shades can help reduce interior temps. You can also insulate battery compartments to keep things cooler.
Make sure your BMS has a temperature sensor on the battery to cut off charging if things get too hot. Thermal runaway is a risk above 140°F as cells overheat and fail.
I recently had a close call on a 95°F desert camping trip. My RV was parked in full sun and I noticed the battery temperature creeping up to 125°F. I quickly moved it into the shade under the RV where temps were a safer 105°F. Lesson learned!
Lithium batteries work hard for us, so we need to be mindful of hot conditions that could damage them. Take simple preventative steps to help your batteries beat the heat.
Clean Battery Terminals
While not the most exciting maintenance task, cleaning your battery terminals can prevent problems down the road. Crocodile clips, cables, and terminals can accumulate corrosion over time, especially if exposed to moisture.
Inspect the terminals a few times per year for any buildup of whitish or greenish oxidation. If present, turn off and disconnect the power system. Then clean the terminals and inside the cable clamps using a wire brush or sandpaper.
Neutralize any remaining acid residue with a solution of baking soda and water. Finally, resecure the clean cable connections and coat the terminals with dielectric grease or petroleum jelly to prevent future corrosion.
It only takes a few minutes to remove corrosion and ensure clean electrical connections between your batteries and system. Don’t let a little oxidation stand in the way of powering your adventures!
Consider Battery Capacity
As lithium batteries age, they gradually lose storage capacity due to crystal formation within the electrodes. After several years of service, your batteries may only hold 80% of original capacity.
If your battery capacity drops too low, it may be time for replacement batteries to restore full power. Consider adding more or larger lithium batteries when upgrading to make up for lost capacity and future degradation.
Pay attention to usage needs – if your RV power demands have increased over time with new accessories, you may benefit from increased battery capacity anyway.
My two 100 Ah Battle Born batteries provided plenty of capacity when my RV was new. But after 4 years of heavy use I noticed I needed to recharge more frequently. I opted to replace them with a single 200 Ah battery to restore capacity. What a difference!
Monitor your runtime and capacities over time. When those lithium batteries start to fade, fresh replacements can give your RV an energizing boost!
Balance Voltages
Lithium batteries contain rows of cells wired together in series. Over many charge/discharge cycles, individual cells can start to drift from one another in voltage. If the mismatch becomes too large, both capacity and lifepsan suffer.
Using a quality BMS that actively balances cell voltages is the best way to maintain battery health. The BMS monitors each cell group and provides microcharging as needed to keep voltages synchronized.
For DIY lithium battery banks without a BMS, you can periodically check and manually balance cell voltages. Use a multimeter to measure each cell or group – they should be within 0.05-0.10V of each other when fully charged. If not, use an independent charger connected to individual cells to bring them to an equal state.
Balancing keeps all cells singing the same tune so your battery bank hits the high notes!
Watch Charging Voltages
Charging is where most of the magic happens for lithium batteries, as long as it’s done properly. Make sure to use a lithium-compatible RV charger or setting.
Follow the manufacturer’s recommended charging voltages – usually around 14.2-14.6V for a 12V nominal lithium battery. Significantly exceeding this risks damage from overcharging.
If your RV allows customizing the charger output, reduce the absorb and float voltages slightly below the standard 14.4V or 14.6V settings used for lead-acid batteries. This gives a little extra breathing room.
I damaged an early lithium battery by overcharging it above 15V with a mismatched charger. Lesson learned – now I use a variable voltage charger programmed specifically for lithium, and my new batteries are going strong.
Keep a close eye on charging performance. Matching charger voltage to your particular lithium battery’s needs prevents premature failure.
Watch Discharge Voltages
Discharging a lithium battery too low can also cause irreversible damage. The BMS should prevent over-discharge during normal use. But external loads could inadvertently drain the battery dangerously low.
Use a low-voltage disconnect to turn off power at a safe level, around 11.7-11.9V for a 12V lithium battery. This protects the battery if the BMS fails or DC loads are directly connected to the battery.
Monitor the battery voltage periodically using your RV monitoring system. Set an alarm if it approaches the low-voltage disconnect threshold. Take proactive steps like reducing loads if voltage drops too low while off-grid.
Accidental over-discharge spoiled two early lithium batteries for me. Now I take extra precautions to manage discharge voltages – those lessons were expensive! Learn from my mistakes.
Consider Temperature Limits
Lithium batteries are designed for decent tolerance of temperature swings. But for maximum lifespan, avoid exposing them to extreme heat or cold wherever possible.
Ideally, try to keep your lithium batteries within about 60-90°F as much as possible. Leaving them in an uninsulated bay exposed to scorching or frigid conditions will degrade performance and capacity over time.
If camping in extreme temperatures, consider moving the batteries indoors or into a heated/cooled compartment. Even just shielding them from the elements helps.
Low temps down to 0°F won’t permanently harm lithium batteries but will drastically reduce available capacity until warmed up. If they fall below freezing, definitely bring them indoors to thaw before charging.
With some smarts about temperature operating limits, your lithium batteries will deliver years of optimal service. Don’t leave them out in the cold!
Address Any Faults
Lithium batteries are complex systems with many components working together. If certain faults occur, the battery may activate safety protections and stop working to prevent hazardous situations.
Common lithium battery faults include:
- High voltage disconnect
- Low voltage disconnect
- High temperature disconnect
- Short circuit protection
- Overcurrent protection
- Open wire protections
If your lithium battery faults, the first step is determining the cause. Check for loose wiring connections, blown fuses, accidental shorts, extreme temperatures, or other external factors. The BMS system will also report fault codes.
Address the root issue, if possible. For instance, if the battery overheated, improve ventilation or reduce thermal load. The battery may automatically reset after cooling down.
For more persistent faults, contact the manufacturer – you may need to cycle the battery’s power to fully reset protections. Don’t bypass or ignore faults, as they indicate an underlying problem.
Pay attention if your lithium battery stops working unexpectedly – the fault usually provides helpful clues about how to get things running smoothly again.
Consider Replacement Batteries
Over an average lifespan of 4-8 years, the cost of lithium batteries per use can be very reasonable. But at some point, the reduced capacity and lower performance of an aging battery bank will make replacement a smart choice.
When battery capacity drops below around 60-70% original capacity, it’s probably time for new batteries. You may also consider replacing them if you need increased capacity for added RV loads.
Installing fresh new lithium batteries can restore that exciting “good as new” feeling and power. The old batteries still have value – many companies offer trade-in discounts. You can also repurpose them for low-power stationary applications.
I plan to replace my current 100 Ah lithiums soon after 4 years of service. The new 200 Ah lithiums will offer more power capacity to accommodate my RV’s growing electricity appetite. Out with the old, in with the new!
With proper care, lithium RV batteries can last 5 years or longer. But the inevitable capacity loss over time makes replacement a reality. Plan for it – you’ll want that new battery excitement!
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