Off-grid, RV & cabin
Enter your daily load and autonomy target. Compare LFP against lead-acid on capacity, weight, and lifespan side by side.
How it works
Step 1
How many days you want the battery to cover without solar input.
Step 2 Panel wattage means little if the inverter cannot carry your loads. The quick inverter size estimator in our Inverters & Equipment section can help you size it for the biggest appliance you run.
LFP and lead-acid compared side by side on the factors that matter most for a trailer. If you want to check this estimate against a second method, the solar panel calculator in our System Sizing section works from your daily load and peak sun hours.
Step 3
Battery weight can be a meaningful share of total trailer payload capacity.
For a 3,500Wh daily load with 2 days of autonomy at 24V, an LFP battery bank weighs around 273 pounds, while an equivalent lead-acid bank weighs roughly 1,050 pounds, a difference of about 777 pounds. On a trailer with axle weight limits, this difference is often decisive on its own, well before considering any other factor. The DOE's overview of battery and energy storage technology keeps the current program details, and it is worth a look before you decide.
Lead-acid batteries are typically limited to about 50% depth of discharge for reasonable lifespan, compared to roughly 80% for LFP batteries, since discharging lead-acid more deeply accelerates plate degradation and shortens usable life. This means a lead-acid bank needs significantly more rated capacity to deliver the same usable energy, which compounds its weight disadvantage on top of lead-acid's already heavier per-Ah weight. The lithium vs lead acid comparison tool weighs the two chemistries on cost, life, and weight for a small space.
LFP batteries are commonly rated for around 3,000 charge cycles, compared to roughly 500 cycles for a typical lead-acid battery, about 6 times the lifespan. For daily-cycling full-time tiny house use, where the battery discharges and recharges every single day, this translates to years of practical difference before a replacement purchase becomes necessary.
Lead-acid can make sense for a tight upfront budget or a stationary tiny house not on a trailer where weight isn't a meaningful constraint, since it costs less per Ah upfront despite its shorter lifespan and heavier weight. For anything mobile or weight-sensitive, which describes most trailer-based tiny houses, LFP is almost always the better long-term choice once weight, lifespan, and total cost of ownership are all weighed together. Battery cost trends behind this comparison come from the National Laboratory of the Rockies Annual Technology Baseline.
Check the system weight and portability calculator to see how your chosen battery fits into your trailer's total payload budget, and run the tiny house solar sizing calculator if you haven't already sized your panel array. The battery lifespan estimator in our maintenance and lifespan tools projects how many years either chemistry should realistically last under daily tiny house cycling, and DOE's overview of battery and energy storage technology is a good next read on the fundamentals behind this whole comparison.
Questions
For a 3,500Wh daily load with 2 days of autonomy at 24V, an LFP battery bank weighs around 273 pounds, while an equivalent lead-acid bank weighs roughly 1,050 pounds, a difference of about 777 pounds. On a trailer with axle weight limits, this difference is often decisive.
Lead-acid batteries are typically limited to about 50% depth of discharge for reasonable lifespan, compared to roughly 80% for LFP batteries. This means a lead-acid bank needs significantly more rated capacity to deliver the same usable energy, compounding its weight disadvantage.
LFP batteries are commonly rated for around 3,000 charge cycles, compared to roughly 500 cycles for a typical lead-acid battery, about 6 times the lifespan. For daily-cycling full-time tiny house use, this translates to years of difference before replacement is needed.
Lead-acid can make sense for a tight upfront budget or a stationary tiny house not on a trailer where weight isn't a constraint, since it costs less per Ah upfront despite its shorter lifespan and heavier weight. For anything mobile or weight-sensitive, LFP is almost always the better long-term choice.
Related tools