What is the best battery to buy for an RV?
The best RV batteries are lithium iron phosphate (LiFePO4) models like the Ampere Time 12V 100Ah, offering 4,000+ deep cycles, 50% weight savings over AGM, and built-in battery management systems (BMS) for thermal protection. For budget-conscious users, Renogy’s AGM 100Ah provides reliable power with 1,100A peak discharge, though with shorter 500-cycle lifespan. LiFePO4 excels in long-term solar/RV use due to zero maintenance and 100% depth of discharge capability.
What’s better for RVs: AGM or LiFePO4 batteries?
LiFePO4 batteries outperform AGM in RV applications through superior cycle life (4,000 vs 500 cycles) and 50% lighter weight. While AGM costs less upfront ($200 vs $400), lithium’s 10-year lifespan and full 100Ah usable capacity make it 70% cheaper long-term. Pro Tip: Use LiFePO4 if running induction cooktops or AC units—their high 100A continuous discharge handles heavy loads.
AGM batteries remain viable for seasonal campers needing basic lighting and fridge support. A 100Ah AGM delivers 50Ah usable before voltage sag, whereas LiFePO4 provides full 100Ah. For example, a 200W solar setup recharges 100Ah LiFePO4 in 5 sun hours versus 10+ for AGM. But what if space is tight? Lithium’s compact size allows stacking two 100Ah units where one AGM would fit.
| Feature | LiFePO4 | AGM |
|---|---|---|
| Cycle Life | 4,000+ | 300-500 |
| Weight (100Ah) | 26 lbs | 60 lbs |
| Cost per Cycle | $0.10 | $0.40 |
How to size an RV battery bank?
Calculate daily power consumption by adding device watt-hours: 100Ah LiFePO4 = 1,280Wh (12.8V x 100Ah). A typical RV fridge uses 1,500Wh/day, requiring 200Ah battery + 400W solar. Pro Tip: Oversize by 30%—cloudy days and inverter losses demand buffer capacity.
For weekenders, 100Ah suffices for lights (10W x 5h = 50Wh) and water pump (50W x 1h = 50Wh). Full-timers needing microwave (1,000W x 0.5h = 500Wh) should opt for 300Ah. Remember, lithium handles 100% discharge vs AGM’s 50% limit—effectively doubling capacity. What about peak loads? A 2,000W inverter needs 166A continuous (2,000W ÷ 12V); use 200Ah LiFePO4 with 100A BMS.
| Usage | Battery Size | Solar Needed |
|---|---|---|
| Weekend | 100Ah | 200W |
| Full-Time | 300Ah | 800W |
| Off-Grid | 600Ah | 1,500W |
Fasta Power Expert Insight
FAQs
Can I mix old and new RV batteries?
Never mix chemistries or ages—imbalanced charging destroys cells. Replace all batteries simultaneously for stable voltage.
Do lithium RV batteries work in cold?
Most LiFePO4 batteries cease charging below 32°F (0°C). Use models with self-heating functions for winter camping.