12V 400Ah LiFePO4 Lithium Battery - 3000+ Cycles Deep Cycle Battery with IP67 Waterproof for RVs and Marine

1. How long will a 12V 400Ah battery power my RV?

A 12V 400Ah battery provides a total energy capacity of $12V times 400Ah = 4.8kWh$ (4,800 Watts).

• Heavy Loads: It can run a 1000W rooftop AC for approximately 4–5 hours.

• Standard Use: It can power a 12V fridge, LED lights, water pumps, and gadgets for 2–3 days on a single charge without solar input.

2. How long does it take to fully charge?

Charging time depends on the output of your charger:

• 50A Charger: Approximately 8 hours.

• 100A Charger: Approximately 4 hours.

• Alternator (DC-DC): Varies by vehicle; we recommend a DC-DC charger to protect your alternator and ensure a 100% full charge.

3. What size solar system is recommended for 400Ah?

To efficiently recharge a 400Ah bank, we recommend a solar array between 600W and 800W.

This setup typically generates 2.5kWh–3.5kWh per day in optimal sun, allowing you to stay "off-grid" indefinitely under moderate power usage.

4. Can I connect multiple batteries in series or parallel?

Yes, our 12V 400Ah batteries are designed for expansion:

• Parallel: Connect up to 4 units to reach a massive 1600Ah capacity.

• Series: Connect up to 4 units to create a 24V, 36V, or 48V system.

Note: Always use batteries of the same brand, age, and capacity, and ensure they are fully charged before connecting them.

5. How does it perform in cold weather/winter?

LiFePO4 batteries can be discharged in temperatures as low as $-20^{circ}C$ ($-4^{circ}F$).

However, charging should not occur below $0^{circ}C$ ($32^{circ}F$).

• Pro Tip: Choose our Self-Heating version if you plan to camp in freezing climates; the BMS will automatically heat the cells before allowing a charge.

6. Why choose 400Ah Lithium over Lead-Acid?

The advantages are significant:

• Lifespan: 3,000–6,000 cycles vs. 300–500 cycles for lead-acid (lasts 10+ years).

• Weight: About 1/3 the weight of an equivalent lead-acid bank, improving your RV’s fuel economy.

• Usable Power: You can safely use 100% of a lithium battery's capacity, whereas lead-acid should only be discharged to 50%.