A lead-acid battery sitting in a Florida storage lot at 100 degrees Fahrenheit loses capacity through a process called sulfation - and what most owners do not know is that heat does not just speed sulfation up, it changes its character. Above 95 degrees, the lead sulfate crystals that form on the plates grow coarser and harder, making them nearly impossible for a standard charger to dissolve. A battery that tested at 80 percent capacity in spring may test below 40 percent by September, even if it was never discharged deeply. The damage accumulates silently, and it is invisible until the bank fails under load.
By Jesse Marcer, Founder - Triton RV Repair | RVIA-Certified | Florida since 2014 | Updated September 6, 2026
Triton RV Repair has been diagnosing failed and degraded battery banks across Florida since 2014. The pattern we see every summer is consistent: owners arrive at a campground after months of storage, hook up the shore power, and assume everything is fine because the monitor reads "full." Then they go off-grid for a night and the inverter shuts down at 9 PM. The batteries were never actually full - they were just sitting at their resting open-circuit voltage, which tells you almost nothing about capacity.
We carry a proper carbon-pile load tester on every service call. That is the only way to measure what a battery bank will actually deliver under real conditions. A load test in the first five minutes of a diagnosis call is what separates a correct answer from a guess.
Why Florida Heat Kills Lead-Acid Batteries at Twice the Rate of Moderate Climates
Battery manufacturers rate cycle life at 77 degrees Fahrenheit. That is the standard test condition, and it represents a climate that most of Florida never sees during the months when coaches sit unused. In Tampa, Orlando, Miami, and Fort Myers, storage temperatures inside an RV - with the black roof absorbing solar radiation - routinely reach 120 to 130 degrees Fahrenheit in July and August. At those temperatures the electrochemical reactions inside a lead-acid cell run faster in every direction, including the ones that cause permanent damage.
The most important of those reactions is the accelerated formation of lead sulfate during partial-state-of-charge storage. When a battery is not fully charged - even slightly - lead sulfate begins forming on the plates. At 77 degrees this process is slow enough that a quality charger can reverse most of it. At 120 degrees the crystals grow larger and harder within days. Conventional multi-stage chargers are designed to dissolve small, soft crystals. They cannot touch the hard deposits that Florida heat creates. The result is permanent capacity loss that no amount of charging will recover.
The second issue is water loss. Flooded lead-acid cells consume water through electrolysis during charging, and heat accelerates that consumption significantly. A cell that needs watering every three months in a temperate climate may need it monthly in Florida. Owners who do not know this let the cells run low, exposing the plates to air - which causes irreversible oxidation damage within hours. We find desiccated flooded cells more often in Florida than in any other context.
Reading the Signs - When Replacement Is the Right Call Versus Reconditioning
Not every battery that tests poorly needs to be replaced immediately. A load test result between 60 and 80 percent of rated capacity, combined with a battery that is less than two years old, may justify an aggressive equalization charge or a pulse-mode desulfation session first. We carry an adjustable pulse charger that can sometimes recover mild sulfation - enough to extend service life for another season in cases where the damage has not fully hardened.
Replacement is the correct call when the load test shows capacity below 50 percent, when internal resistance is elevated to the point where the bank cannot sustain its rated amperage for more than a few seconds, when cells are showing physical distortion or acid stratification, or when the battery is more than four years old and has spent multiple Florida summers in storage. At that point a desulfation attempt will recover some function temporarily but will not address the structural degradation of the plates. The money is better spent on new chemistry.
The honest conversation we have with every customer is about what they are actually replacing. A four-battery flooded bank in a 2012 coach was designed with the assumption that the owner would maintain it carefully and replace it on a regular schedule. Most owners do not. When those batteries fail, replacing them with an equivalent flooded bank means committing to the same maintenance regimen. If that is not realistic, the smarter investment is a chemistry that tolerates Florida conditions without constant attention.
Lithium LFP vs AGM - The Florida-Specific Tradeoff Analysis
Lithium iron phosphate batteries do not sulfate. That single fact removes the primary failure mode of lead-acid chemistry in this climate. LFP also delivers approximately twice the usable capacity per rated amp-hour - a 100Ah LFP battery can be safely discharged to 20 percent, giving you 80 amp-hours of usable energy, while a 100Ah AGM should not go below 50 percent without losing cycle life, giving you 50 amp-hours. In a Florida boondocking context where you are running a fan, lighting, and a 12-volt refrigerator, that difference is the gap between a comfortable night and a dead bank by morning.
The case for AGM is narrower but real. AGM batteries are fully compatible with every stock RV converter and charger. You can drop a properly sized AGM bank into a coach and charge it correctly without touching anything else in the system. They also have a lower upfront cost per amp-hour, though the lifecycle math over three to five years usually favors LFP. For owners who only use their coach on full hookups and never dry-camp, the full-charge and maintenance requirements of AGM are manageable, and the upgrade premium of LFP may not pay back quickly enough to justify it.
For full-timers, frequent boondockers, and anyone running solar, LFP wins on almost every metric in a Florida environment. The chemistry handles heat better, charges from solar panels more efficiently because it accepts current at a higher rate, and has a rated cycle life of 2,000 to 3,000 cycles at 80 percent depth of discharge compared to 300 to 500 cycles for comparable AGM. The battery management system included in every quality LFP cell provides overcharge, over-discharge, and thermal protection that flooded and AGM banks simply do not have.
Converter Compatibility - The Hidden Issue in Every Lithium Upgrade
The single most common mistake in a DIY lithium upgrade is connecting LFP batteries to a converter that was designed for flooded lead-acid and leaving it unchanged. Stock converters in coaches built before 2020 almost universally hold a float voltage of 13.4 to 13.6 volts - the correct maintenance voltage for lead-acid. An LFP battery sitting at that voltage is chronically undercharged. It will read somewhere around 70 to 80 percent state of charge and stop climbing. The converter simply does not push voltage high enough to finish the job.
The consequences are subtle at first. The battery functions, but it never reaches full capacity. You get fewer hours of runtime than you expect. Over time, partial-state-of-charge storage creates its own issues even for LFP, and the investment in lithium delivers less benefit than it should. The fix is either replacing the converter with a unit that has a dedicated lithium profile - which is the cleanest solution - or adding an external DC-DC charger that receives current from the converter and re-conditions it for LFP. We evaluate the existing electrical system before every lithium installation and provide a clear recommendation based on what the coach actually has.
DC-DC Chargers and Alternator Charging - What Changes With Lithium
In a lead-acid system, the alternator charges the house battery bank through a simple isolator or a battery-to-battery relay. This works reasonably well because the charge acceptance profile of lead-acid is forgiving - the voltage delivered by the alternator overlaps sufficiently with what the battery needs. Lithium changes the equation. An LFP bank accepts current at a higher rate and needs a higher absorption voltage than the alternator's default output provides.
Connecting LFP batteries directly to an alternator through a traditional isolator causes two problems. First, the batteries may draw more current during bulk charging than the alternator is rated for over extended periods, which shortens alternator life. Second, the charging efficiency is poor because the voltage relationship is mismatched. A DC-DC charger - sometimes called a battery-to-battery charger - sits between the alternator circuit and the LFP bank, draws a controlled current from the starting circuit, and delivers the correct multi-stage charge profile to the lithium bank. For coaches where driving time is part of the charging strategy, this is not an optional accessory - it is what makes the system work correctly.
Amp-Hour Sizing - How to Calculate What a Florida Dry-Camper Actually Needs
Sizing a battery bank correctly requires honest accounting of your actual daily loads - not optimistic estimates. The most useful starting point is a clamp meter on the main feed wire from the battery for a full day of normal use, but we can also work from the nameplate ratings of your appliances. A residential-style 12-volt compressor refrigerator draws 4 to 6 amps on average over a 24-hour period - call it 5 amps times 24 hours, which is 120 amp-hours per day just for the refrigerator. Add a rooftop vent fan at 2 to 3 amps running eight hours, which is another 20 amp-hours. LED lighting for four hours adds 4 to 8 amp-hours. Phone and device charging adds another 5 to 10 amp-hours. A realistic single-day load for a typical Florida boondocker without air conditioning runs 150 to 170 amp-hours.
With AGM at 50 percent maximum depth of discharge, that requires a 300 to 340 amp-hour installed bank for a single night. With LFP at 80 percent usable depth, a 200 amp-hour bank covers the same load with margin to spare. If you add a rooftop solar panel - even a single 200-watt panel in Florida sun - the math changes entirely, because the battery is being replenished throughout the day and the overnight load is all that needs to be carried. Two hundred amp-hours of LFP plus 200 to 400 watts of solar is a combination that handles indefinite dry-camping across most of Florida for most of the year.
Service Pricing for RV Battery Work in Florida
All battery work is performed at your location - campground, storage lot, driveway, or marina. The service call and load test covers the diagnostic work and cable inspection regardless of what we find. Battery pricing below reflects installed cost including hardware, terminals, and wiring. Converter evaluation and upgrade pricing is provided separately after the compatibility check.
| Service | Price Range | Notes |
|---|---|---|
| Service call + load test | $299 - $399 | Includes load test on existing bank and cable inspection |
| Single 6V GC2 flooded battery | $95 - $145 | Per battery; most coaches run 2 or 4 in series |
| Dual AGM 100Ah bank (installed) | $450 - $850 | VMAXTANKS or equivalent; sealed, no maintenance |
| 100Ah lithium LFP battery (installed) | $650 - $1,100 | Single 100Ah LFP; full BMS |
| 200Ah lithium + DC-DC charger | $1,400 - $2,400 | Complete bank; DC-DC for alternator charging |
Pricing reflects national averages and will vary by coach configuration, battery compartment access, and current component costs. These ranges are provided as a planning reference. A specific quote is generated on-site after the load test and system evaluation. Prices do not include converter replacement if required.
Triton RV Repair does not publish flat rates. Battery and electrical work varies too much by coach to be accurately quoted without seeing the system. We provide a written estimate before any parts are ordered.
Frequently Asked Questions
Why do RV batteries fail so fast in Florida summers?
+The short answer is heat-accelerated sulfation. When a lead-acid cell sits above 95 degrees Fahrenheit - which is a daily reality in a Florida storage lot - lead sulfate crystals form on the plates faster than normal charging can dissolve them. Over a single summer the crystals harden and become permanent, cutting usable capacity in half or worse. The battery may still show voltage, but it cannot hold a load. Lithium iron phosphate chemistry does not sulfate and tolerates heat far better, which is why Florida owners who switch to LFP rarely go back.
Should I upgrade to lithium or stick with AGM?
+AGM makes sense if your converter is not lithium-compatible and you do not want to replace it, or if your budget is tight and you are comfortable with a bank that requires some management. Lithium LFP delivers roughly twice the usable capacity per pound, charges faster, handles heat better, and lasts three to five times as many cycles. For full-timers and frequent boondockers in Florida, the upgrade math almost always works out in two to three years. For occasional weekend campers who are always on hookups, AGM may be all you need.
How many amp-hours do I actually need for camping without hookups?
+Start with your daily load in amp-hours, then double it to avoid draining below fifty percent with lead-acid - or factor in about eighty percent usable capacity with lithium. A realistic Florida dry-camp day with a single rooftop fan, LED lighting, a 12-volt refrigerator, and phone charging runs roughly 80 to 120 amp-hours. A 200Ah LFP bank gives you two comfortable nights without solar. Add a rooftop panel and the equation changes entirely - the battery becomes a buffer rather than a fuel tank.
Will my existing converter charge a lithium battery correctly?
+Usually not without adjustment. Most stock RV converters are optimized for flooded lead-acid, which means they hold a float voltage of around 13.6 volts - too low to fully charge an LFP bank, which needs 14.4 to 14.6 volts to reach full capacity. Some newer converters have a lithium mode. Older units should either be set to their highest bulk-charge profile or replaced with a proper multi-stage lithium charger. We check converter compatibility as part of every lithium upgrade and will tell you exactly what your coach needs before we install anything.
What causes batteries to sulfate and how do I prevent it?
+Sulfation starts the moment a lead-acid battery sits in a partial state of charge - which happens whenever you store a coach without fully charging it first, or whenever the converter holds it at too low a voltage over time. Florida heat speeds the crystal formation dramatically. Prevention means keeping the battery fully charged during storage, using a quality multi-stage charger rather than a single-stage trickle charger, and checking water levels in flooded cells monthly. A desulfation pulse charger can sometimes reverse mild sulfation, but once the crystals harden - typically after several months in Florida heat - the capacity loss is permanent.
Sources and Further Reading
The following reference materials were used in preparing this page and are provided for owners who want to read the underlying technical documentation.
Battle Born LFP battery specs - Lithium iron phosphate cycle life, charge requirements, and thermal performance.
Renogy RV battery documentation - AGM and lithium battery specs and charging compatibility guides.