Combien de temps durera une batterie au lithium 48V 100AH?

Combien de temps durera une batterie au lithium 48V 100AH?
Considering a 48V 100Ah lithium battery for your energy storage needs? It’s a popular size, especially for residential solar systems or robust backup power. But the big question on everyone’s mind is: how long will it actually last on a single charge? La vérité est, its endurance depends entirely on what, and how much, you’re powering.

A 48V 100Ah lithium battery stores approximately 4.8 kilowatt-hours (kWh) d'énergie (48 Volts x 100 Amp-hours = 4800 Wattheures). How long this 4.8 kWh will last can range from just a few hours if you’re running heavy loads, to over a day if you’re only powering essential, low-wattage devices. Par exemple, it could power a continuous 480-watt load for about 10 heures, or a 100-watt load for nearly 48 heures, assuming you can use its full capacity (modern LFP lithium batteries often allow for very deep discharge).

Image of a 48V 100Ah rack mount lithium battery module, perhaps with a superimposed graphic showing its 4.8kWh capacity and example runtimes for different loads.
48V 100Ah Lithium Battery Runtime Examples

À Gycx Solaire, we often work with 48V rack mount lithium batteries, typically using safe and long-lasting Lithium Iron Phosphate (LFP) chimie. These modular units, often coming in 100Ah capacities (around 5kWh each), are fantastic for building scalable energy storage systems. Let’s break down how to figure out runtime and answer some other common questions about these workhorse batteries.

What is the difference between 100Ah and 200Ah battery?

When you’re looking at batteries, you’ll see capacity ratings like 100Ah or 200Ah. If you’re trying to decide which size is right for you, what’s the actual difference in practical terms? Understanding this directly impacts how long your stored energy will last.

Assuming both batteries are of the same voltage (Par exemple, both are 48V systems), un 200Ah battery has exactly twice the energy storage capacity as a 100Ah battery. This means, for the same connected load, the 200Ah battery will provide roughly twice the runtime. Consequently, a 200Ah battery will also be physically larger, heavier, and more expensive than a 100Ah battery of the same chemistry and build quality.

Side-by-side comparison graphic: a 48V 100Ah battery (4.8kWh) next to a 48V 200Ah battery (9.6kWh), showing the difference in stored energy.
100Ah vs. 200Ah Battery Capacity Comparison

Plonger plus profondément: Amp-hours, Kilowatt-hours, and What They Mean for You

Let’s get a clear understanding of these terms:

  • Amp-hours (Ah): This rating tells you how many amps a battery can theoretically deliver for a certain number of hours. A 100Ah battery could (in theory) deliver 100 amps for 1 heure, ou 10 amps for 10 heures, ou 1 amp for 100 heures.
  • Kilowatt-hours (kWh): This is the true measure of the total énergie stored in the battery. It’s what you pay for on your electricity bill. You calculate it by:
    kwh = (Tension (V) x ampli-heures (Ah)) / 1000
    • For a 48V 100Ah battery: (48V x 100Ah) / 1000 = 4.8 kWh
    • For a 48V 200Ah battery: (48V x 200Ah) / 1000 = 9.6 kWh

Donc, the 48V 200Ah battery stores 9.6 kwh d'énergie, while the 48V 100Ah battery stores 4.8 kWh.

  • Runtime Implication: If you have a consistent load, say 500 watts (0.5 kW):
    • 48V 100Ah (4.8 kWh) temps d'exécution: 4.8 kWh / 0.5 kW = 9.6 heures (approximate, before considering Depth of Discharge).
    • 48En 200h (9.6 kWh) temps d'exécution: 9.6 kWh / 0.5 kW = 19.2 heures (approximate).
  • Physical Size and Weight: En général, doubling the Ah capacity while keeping the voltage and cell chemistry the same means roughly doubling the number of internal cells, leading to an almost proportional increase in size and weight.
  • Coût: More capacity means more raw materials and cells, so a 200Ah battery will cost more than a 100Ah one.
  • Scalability with Rack Mount Batteries: This is where our Gycx Solar 48V rack mount lithium batteries shine. Many are designed as ~100Ah (5kWh) modules. If you need 200Ah (10kWh) of storage, you simply install two of these modules in parallel. Need 300Ah (15kWh)? Add a third. This modularity allows you to precisely size your system and expand it later if your needs grow.

How many solar panels do I need to charge a 48V lithium battery?

You’ve decided on a 48V lithium battery bank, perhaps a robust 100Ah (4.8kWh) LFP module, and you want to charge it efficiently with solar power. How do you figure out the right number and size of solar panels for the job? Proper sizing is key to ensuring your battery gets fully charged in a reasonable timeframe.

The number of solar panels needed depends on several factors: ton battery’s total capacity (kWh) that needs to be replenished, ton geographic location’s average daily peak sun hours, le wattage of the solar panels you choose, et le efficiency of your solar charge controller and overall system. As a rough example, to reliably charge a 4.8kWh (48V 100Ah LFP) battery daily, assuming 4-5 peak sun hours and typical system efficiencies, you might need around 1 kilowatt (kW) à 1.5 kW of solar panels. This could be three 400W panels or four 350W panels, for instance.

Infographic showing solar panels charging a 48V rack mount battery through a charge controller, with factors like sun hours and panel wattage highlighted.
Sizing Solar Panels for 48V Lithium Battery

Plonger plus profondément: Calculating Your Solar Array Size

Here’s a more detailed approach to sizing your solar array for your 48V lithium battery:

  1. Determine Daily Energy to Replenish (kWh):
    • If you’re cycling your 48V 100Ah (4.8 kWh) battery daily and using, say, 80% of its capacity (Profondeur de décharge - DOD), you need to replenish: 4.8 kWh * 0.80 = 3.84 kWh.
  2. Find Your Average Peak Sun Hours: This is crucial and varies by location and time of year. It’s not just total daylight hours, but the equivalent hours of full, peak sunshine. You can find this data for your area online (Par exemple, from NREL maps for the US). Let’s assume you get 4 peak sun hours per day on average.
  3. Account for System Losses & Inefficiencies: Not all the power your panels produce makes it into your battery. Expect losses from:
    • Solar panel temperature derating (panels produce less when hot).
    • Wiring losses.
    • Charge controller efficiency (MPPT controllers are typically 90-98% efficace, PWM are less).
    • Battery charging efficiency (LFP is very good, souvent >95%).
    • Panel soiling, aging, etc..
      A conservative estimate for total system losses might be 15-25%. Donc, your effective efficiency factor might be around 0.75 à 0.85.
  4. Calculate Required Solar Array Power (kW):
    • Formule: Solar Array Power (kW) = Daily Energy Needed (kWh) / (Peak Sun Hours x System Efficiency Factor)
    • Exemple: Using our figures: 3.84 kWh / (4 hours x 0.80 efficacité) = 3.84 / 3.2 = 1.2 kW.
      Donc, you’d need a solar array of approximately 1200 watts (1.2 kW).
  5. Choose Panel Wattage and Number: You could achieve 1200W with three 400W panels, or four 300W panels, etc..
  6. Voltage Configuration for 48V Battery: The solar panels must be wired in series/parallel strings to provide a voltage that is:
    • Higher than the battery’s charging voltage (a 48V LFP battery might charge up to ~57.6V).
    • Within the operating input voltage window of your MPPT solar charge controller.
      Typiquement, for a 48V battery system, you’d want an array VOC (Tension en circuit ouvert) significantly higher, often in the 70V-150V range or more, depending on the charge controller.

Gycx Solar Story: We recently designed an off-grid system for a client using two of our 48V 100Ah rack mount LFP batteries (9.6Kwh total). Based on their location’s sun hours and energy needs, we paired it with a 2.5kW solar array and a high-efficiency MPPT charge controller. This ensures their batteries are fully charged even on days with less-than-perfect sun, providing reliable power.

Quels sont les inconvénients des batteries au lithium pour les panneaux solaires?

Batteries au lithium, especially LFP types like those in our Gycx Solar 48V rack mount lithium battery solutions, are an excellent choice for solar energy storage due to their long life, grande efficacité, et la sécurité. Cependant, Comme toute technologie, they aren’t without some potential considerations or perceived disadvantages when compared to other options or ideal scenarios.

The primary disadvantages often cited for lithium batteries in solar applications include their higher upfront cost compared to traditional lead-acid batteries (though their longer lifespan often results in a lower total cost of ownership). They can also be sensitive to extreme temperatures (both very hot and very cold), requiring a good Battery Management System (GTC1. ) and sometimes thermal management for optimal performance and longevity. While generally very safe (Surtout LFP), their high energy density means specific charging requirements must be met (handled by the BMS and charge controller), et end-of-life recycling is an evolving industry, though rapidly improving.

Balanced image: A sleek lithium solar battery with a small
Lithium Battery for Solar: Pros and Cons Balance

Plonger plus profondément: A Balanced Look at Lithium for Solar

Let’s address these points constructively:

  • Coût initial: This is often the biggest hurdle. Batteries au lithium, particularly high-quality LFP cells with integrated BMS, have a higher initial purchase price than older technologies like flooded lead-acid.
    • Gycx Solar Perspective: We encourage customers to look at the Total Cost of Ownership (TCO) ou Levelized Cost of Storage (LCOS). Lithium batteries offer many more cycles (Par exemple, 6,000+ for LFP vs. 500-1,000 pour le plomb-acide), deeper discharge capability, efficacité supérieure, and are maintenance-free. Over their 10-20 year lifespan, they often prove to be more economical.
  • Temperature Sensitivity:
    • Lithium batteries perform best in moderate temperatures (Par exemple, 15-30°C or 59-86°F). Extreme cold can temporarily reduce their available capacity and ability to accept a charge. Extreme heat can accelerate degradation and shorten their lifespan.
    • Gycx Solar Perspective: Our recommended LFP rack mount batteries come with an integrated BMS that includes temperature monitoring and protection. For installations in challenging climates, we can also design systems with appropriate enclosures and even active thermal management if needed to keep the batteries within their optimal operating range.
  • Specific Charging Requirements:
    • Lithium batteries need precise voltage and current control during charging, managed by a compatible charge controller and the BMS. You can’t just connect them to any power source.
    • Gycx Solar Perspective: This is a non-issue with professionally designed systems. We ensure that the solar charge controller (often part of a hybrid inverter) is perfectly matched to the specifications of the LFP batteries, providing optimal and safe multi-stage charging.
  • Environnement & Recycling Concerns:
    • The mining of lithium and other materials, and the energy used in manufacturing, have an environmental footprint. End-of-life recycling for lithium batteries is more complex than for lead-acid.
    • Gycx Solar Perspective: We favor LFP chemistry, which notably avoids cobalt and nickel – two materials with significant environmental and ethical sourcing concerns. The lithium battery recycling industry is also growing rapidly, with more facilities and improved processes becoming available to recover valuable materials. We encourage responsible end-of-life management.

While these are valid considerations, the significant advantages of LFP lithium batteries – their long cycle life, grande efficacité, deep discharge capability, sécurité, and maintenance-free operation – make them the leading choice for modern solar energy storage solutions.

Can I charge my lithium battery directly from a solar panel?

You have a solar panel, and you have a lithium battery. It might seem logical to just connect the two directly to get your battery charged up with free sun power. Cependant, this is a common question with a very important answer for the safety and health of your battery.

Non, you absolutely should pas charge a lithium battery (including a 48V system like our rack mount units) directly from a solar panel without a crucial intermediary device. You must use a solar charge controller positioned between the solar panel(s) and the battery. The charge controller’s job is to regulate the voltage and current coming from the solar panels to ensure the battery is charged safely, efficacement, and without risk of overcharging or other damage.

Can I Connect A Solar Panel Directly To Battery Actual **X (No Direct Connection)** -> Batterie. Alors, Solar Panel -> **Contrôleur de charge (Correct!)** -> Battery.”>
Correct Way to Charge Lithium Battery from Solar Panel

Plonger plus profondément: Why a Charge Controller is Non-Negotiable

Here’s why direct connection is a bad idea and why a charge controller is essential:

  1. Voltage Incompatibility & Regulation: Solar panel output voltage fluctuates significantly with sunlight intensity and panel temperature. This voltage can often be much higher than the safe maximum charging voltage for your lithium battery. Par exemple, a panel designed to charge a 12V system might have an open-circuit voltage (COV) of 22V or higher. A 48V nominal LFP battery needs a precisely controlled charging voltage (Par exemple, up to around 56-58V). Connecting a panel directly could instantly send damagingly high voltage to the battery. A charge controller (especially an MPPT type) takes the variable panel output and converts it to the optimal, stable voltage required by the battery.
  2. Current Control: Solar panels can also produce high currents in bright sun. While batteries can accept current up to a certain rate (their "C-rate"), exceeding this can cause overheating and damage. A charge controller limits the current to a safe level for the battery.
  3. Protection contre la surcharge: This is perhaps the most critical function. Lithium batteries are very sensitive to overcharging. If you continuously push current into a full lithium battery, it can lead to overheating, swelling, venting, and potentially thermal runaway (fire). A charge controller senses when the battery is full and stops the charging process or switches to a very low "float" actuel (if applicable for the chemistry and BMS settings).
  4. Optimized Charging Stages: Modern charge controllers (especially MPPT types) use multi-stage charging algorithms (Par exemple, Bulk, Absorption, Float – though "Float" is less critical or different for LFP) to charge the battery efficiently and promote its longevity. Direct connection offers no such intelligence.
  5. Reverse Current Prevention: At night, or when the panel voltage is lower than the battery voltage, a charge controller prevents current from flowing depuis la batterie back to the solar panel, which would drain the battery.

Gycx Solar Story: We once encountered a DIY setup where someone had tried to directly charge a small lithium battery from a panel. The battery was swollen and clearly damaged. It underscored for us why we always emphasize that every Gycx Solar system, from the smallest to the largest, incorporates a high-quality MPPT charge controller precisely matched to the solar array and our 48V rack mount LFP batteries. It’s fundamental for safety and system lifespan.


Understanding how long a 48V 100Ah lithium battery will last involves looking at your specific energy needs, while choosing between capacities like 100Ah and 200Ah depends on your desired runtime and budget.
Charging these advanced batteries safely and effectively from solar panels always requires a properly sized solar array and a dedicated charge controller. While lithium batteries have some considerations, their benefits for solar storage, especially LFP types in modular rack mount designs, are compelling.

If you have more questions about 48V rack mount lithium batteries, how to size a system for your needs, or the best way to integrate them with solar, the Gycx Solar team is here to provide expert guidance. Contact us today to discuss your energy storage project!


  1. Understand the related equipment components of LiFePO4 battery, such as Battery management system, in order to better compare and understand the data concepts related to lithium batteries. Cela vous aidera à choisir un produit qui convient mieux à vos besoins.

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