When you invest in an AGV fleet, the real question is not just “How big is the battery?”, but “How long will it last before I must replace it?”
Battery life directly affects uptime, maintenance cost and the payback period of your automation project.
This guide explains:
- Typical AGV battery life for lead-acid, AGM, lithium and LiFePO4
- What “lifespan”, “cycle life” and “SOH” actually mean
- How to estimate the remaining life of the batteries you already have
- When it makes sense to plan AGV battery replacement and upgrade to LiFePO4
How Long Do AGV Batteries Usually Last?
In practice, AGV battery life is a range, not a single number. For typical warehouse and factory environments:
- Lead-acid / flooded / basic industrial batteries
- Around 3–5 years
- Roughly 300–500 deep cycles (e.g. 80% depth of discharge)
- AGM and other sealed lead-acid batteries
- Around 3–6 years
- Roughly 400–700 deep cycles
- Standard lithium-ion (NMC, NCA, etc.)
- Around 5–7 years
- Roughly 1,500–3,000 cycles
- LiFePO4 lithium iron phosphate (for AGVs)
- Around 8–10+ years in many applications
- Roughly 2,000–6,000 cycles, depending on depth of discharge and charging strategy
These are typical ranges, not guarantees. A lightly-used AGV in a clean, air-conditioned environment can exceed them. A heavily loaded AGV running 24/7 in a hot, dusty plant may fall short.
What this article does is help you:
- Understand how chemistry + duty cycle + charging + temperature create that final lifetime
- Estimate the remaining life of your existing batteries
- Decide when to plan replacement and whether an upgrade to LiFePO4 AGV batteries is worth it
What Does “AGV Battery Life” Really Mean?
When someone says “this battery lasts five years”, they usually mix several different ideas. Clarifying them makes decisions simpler.
Calendar life vs cycle life
- Calendar life is the number of years the battery can remain in service under normal conditions.
- Cycle life is the number of charge–discharge cycles the battery can handle at a given depth of discharge (DoD) before its capacity drops to a defined threshold (often 70–80% of original).
Example:
“2,000 cycles at 80% DoD” means the manufacturer expects about 2,000 full 80% discharge–recharge cycles before the battery’s capacity falls to the specified threshold.
For AGVs, both calendar life and cycle life matter, because:
- A lightly used AGV might reach calendar limits before cycle limits.
- A heavily used 3-shift AGV might hit cycle limits in just a few years.
State of Health (SOH) and usable life
State of Health (SOH) is a way to express how much useful life remains compared with a new battery. It usually combines:
- Remaining capacity (Ah or kWh)
- Internal resistance
- Other degradation indicators
From an operational point of view:
- An AGV battery at 100% SOH delivers the runtime specified when it was new.
- Around 80% SOH, you start to feel that “one charge doesn’t go quite as far”.
- Around 70% SOH and below, runtime losses, alarms and downtime become hard to ignore.
In other words, a battery is not dead or alive; it slowly loses performance until it no longer supports your shifts reliably.
AGV duty cycle and battery life
The same battery can have a very different lifespan in different tasks:
- Light-duty AGV: low payload, short distances, single shift → lower daily energy, fewer cycles → longer life.
- Heavy-duty or 24/7 AGV: high payload, long routes, frequent acceleration → more cycles, higher currents → shorter life.
This is why published life numbers must always be interpreted together with the duty cycle of your fleet.
AGV Battery Lifespan by Chemistry: Lead-Acid, AGM, Lithium & LiFePO4
Lead-acid AGV batteries
Classic lead-acid (flooded or basic industrial types) are still used in many AGVs:
- Typical life: 3–5 years
- Typical cycle life: ~300–500 deep cycles (around 80% DoD)
They are relatively inexpensive upfront, but:
- They dislike deep discharge and long periods in a discharged state.
- They need regular maintenance (water topping, checking corrosion).
- Opportunity charging and partial charges can shorten life if not carefully controlled.
AGM and other sealed lead-acid batteries
AGM (Absorbent Glass Mat) and other sealed variations improve convenience:
- No regular topping up of electrolyte
- Less risk of acid spills
Typical figures:
- Calendar life: 3–6 years
- Cycle life: ~400–700 cycles (depending on DoD and temperature)
They are often chosen when a maintenance-free lead-acid solution is needed but the basic lead-acid limitations still apply: sensitivity to deep discharges, high temperature and high current peaks.
Standard lithium-ion (NMC / NCA, etc.)
Lithium-ion chemistries such as NMC and NCA offer:
- Higher energy density (more energy in less weight and volume)
- Good cycle life compared with lead-acid
Typical ranges:
- Calendar life: 5–7 years
- Cycles: 1,500–3,000 at moderate DoD
These chemistries are more common in smaller mobile robots and electronics. In AGVs, they can work very well if thermal management and BMS protection are properly designed.
LiFePO4 AGV batteries
LiFePO4 (lithium iron phosphate) has become the preferred lithium chemistry for many industrial AGV systems:
- Calendar life: 8–10+ years in suitable environments
- Cycle life: 2,000–6,000 cycles at typical AGV depths of discharge
- Very robust for frequent opportunity charging and partial charges
- Improved safety and thermal stability compared with many other lithium chemistries
For multi-shift, 24/7 and high-uptime fleets, LiFePO4 often delivers the lowest cost per delivered kWh over the full life of the system.
Comparison table: lifespan & cycles by chemistry
| Chemistry | Typical Calendar Life* | Typical Deep-Cycle Count* | Maintenance Level | Typical AGV Use Cases |
|---|---|---|---|---|
| Flooded lead-acid | 3–5 years | 300–500 (≈80% DoD) | High | Older AGVs, low-cost projects, manual battery rooms |
| AGM / sealed lead-acid | 3–6 years | 400–700 (≈70–80% DoD) | Medium | Cleaner environments, where low maintenance is needed |
| Standard Li-ion (NMC, NCA) | 5–7 years | 1,500–3,000 | Low | Compact AMRs, robots where weight is critical |
| LiFePO4 for AGV | 8–10+ years | 2,000–6,000 | Low | Modern AGVs & AMRs, multi-shift & opportunity charging |
*Values are indicative ranges; actual life depends heavily on duty cycle, temperature, DoD and charging strategy.
Key Factors That Influence AGV Battery Life
Depth of discharge (DoD)
Depth of discharge is how much of the battery’s capacity you use before recharging.
- Deep cycles (for example 0–100% SOC) put more stress on the cells.
- Moderate cycles (for example 20–80% SOC) are much gentler.
For many chemistries:
- Reducing DoD from 80% to 50% can increase cycle life dramatically.
- LiFePO4 benefits in particular from working in the mid-SOC range.
This is one reason why opportunity charging can extend life: it keeps the battery in a more comfortable SOC window.
Charging strategy: overnight vs opportunity charging
Charging strategy is another big lever:
- Overnight bulk charging with deep discharge
- Common for lead-acid systems.
- Longer downtime and deeper daily cycles → shorter life, especially in multi-shift operations.
- Opportunity charging with LiFePO4
- Many short charges during the day while AGVs wait for tasks.
- Shallower, more frequent cycles keep SOC away from both empty and full extremes.
- This can extend effective life and reduce runtime complaints.
If you want to dive deeper into charging strategies, you can refer to your AGV Battery Charging Guide and design the charging system around life as well as uptime.
Temperature and environment
Batteries are sensitive to temperature:
- High temperatures accelerate all aging mechanisms.
- Very low temperatures limit charging current and may lead to lithium plating if charged too fast.
Environmental factors such as dust, moisture, shock and vibration also influence:
- The integrity of connectors and bus bars
- The cooling and mechanical stability of the pack
Good enclosure design, ventilation and mounting reduce these risks.
C-rate, current peaks and power demand
High C-rate discharge (relative to battery capacity) generates more:
- Heat
- Voltage sag
- Mechanical and chemical stress
If an AGV is consistently operating near its maximum acceleration or climbing slopes with heavy loads, the battery experiences more stress.
Sizing the pack with enough capacity and power margin is not only about runtime; it is also about preserving lifespan.
Maintenance, storage and balancing
Proper care makes a noticeable difference:
- Lead-acid and AGM need:
- Correct charging profiles
- Avoidance of chronic under-charging
- Periodic checks for corrosion and cable condition
- Lithium and LiFePO4 need:
- Healthy BMS balancing so cell voltages remain aligned
- Avoidance of very long storage at 0% or 100% SOC
- Reasonable temperatures during long shutdowns
Even simple habits—like not leaving parked AGVs deeply discharged for weeks—can add months or years to battery life.
How to Estimate the Remaining Life of Your AGV Batteries
You don’t always have to guess. A few checks can give a good picture of how much life is left.
Age, cycles and warranty benchmarks
Start with what you know:
- Installation date – how many years have the batteries been in operation?
- Operating pattern – single shift, two shifts or 24/7?
- Rough estimate of cycles per year (for example: one full cycle per shift).
Multiply cycles per year by years in service to get an approximate cycle count, then compare with:
- The manufacturer’s datasheet values
- Warranty terms (for example 5 years or 2,000 cycles)
If you are already near or beyond those numbers, it is reasonable to assume the batteries are in the last part of their life.
Runtime check: does one charge still cover the shift?
A very practical method:
- Remember or record how long a new battery could run between charges (in hours or missions).
- Measure the same value now under similar conditions.
If runtime has fallen by 20–30% or more, your effective capacity has significantly decreased and a large part of the cycle life has been consumed.
Observed symptoms of low SOH
Other signs of aging include:
- More frequent low-voltage or “battery low” alarms during normal shifts
- AGVs needing to visit chargers earlier than scheduled
- Noticeable heating of batteries under loads that were previously easy
- In lead-acid systems, more frequent topping-up, sulfation or visible corrosion
When these patterns appear across multiple vehicles, not just one, the fleet is likely approaching replacement time.
Using BMS data to assess SOH (for lithium packs)
Lithium and LiFePO4 AGV battery packs usually include a Battery Management System (BMS) that stores useful data:
- Total cycle count
- Estimated SOH or remaining capacity
- Voltage and temperature history
Consulting BMS logs with your battery supplier or integrator lets you:
- Confirm whether degradation is normal or accelerated
- Identify misuse such as repeated high-temperature operation or overcharging
- Plan replacement or upgrades before unexpected failures occur
When Should You Replace an AGV Battery?
Not every capacity loss means you must replace the battery immediately. But waiting too long has its own risks.
Practical SOH thresholds for replacement
Many operations use a practical rule:
- Around 80% of original capacity → watch more closely, begin planning.
- Around 70–75% → schedule replacement or refurbishment.
Below this point, AGVs increasingly fail to complete shifts, opportunity charging becomes less effective, and the risk of unplanned downtime rises.
Risks of running AGV batteries “to the bitter end”
Trying to squeeze the last bit of life out of a tired battery can cost more than it saves:
- Unexpected stops in narrow aisles or at critical points in the process
- Increased safety risks when vehicles behave unpredictably
- Higher maintenance cost due to repeated troubleshooting and emergency swaps
- Damage to customer trust if AGVs are part of a service you provide
A structured replacement policy usually costs less over time than reactive emergency replacements.
Planned vs reactive AGV battery replacement
- Planned replacement
- You set internal thresholds (age, cycles, SOH, runtime), then schedule replacements during downtime.
- You can evaluate options calmly, negotiate pricing and, if desired, upgrade technology.
- Reactive replacement
- You wait until batteries fail or cause serious disruption.
- You pay in rush costs, lost production and operational stress.
The goal is to move as much as possible into the “planned” category.
AGV Battery Replacement Options & Cost Considerations
When replacement time comes, you have strategic options—not just “buy the same again”.
Replace with the same chemistry
Replacing lead-acid with the same type keeps everything familiar:
Pros
- Usually no changes needed to existing chargers and charging rooms
- Minimal engineering effort and downtime
Cons
- The same maintenance and lifetime limitations continue
- More frequent replacements over the life of the AGV system
- Less suitable for multi-shift and 24/7 operations
This approach may be acceptable in low-duty applications or where budgets are very tight.
Upgrade to lithium or LiFePO4
Upgrading to LiFePO4 AGV batteries typically offers:
- Longer cycle life and calendar life
- Better performance under opportunity charging and higher C-rates
- Smaller, lighter packs for the same usable energy
- Lower lifetime cost per kWh delivered
For fleets already considering automation upgrades, this is often the right moment to move away from lead-acid entirely.
Cost ranges and total cost of ownership (TCO)
Exact prices depend on capacity, voltage, certifications and integration work, but in general:
- A LiFePO4 pack of equivalent energy costs more upfront than a lead-acid pack.
- Over its life, LiFePO4 typically delivers many more usable kWh and needs fewer replacements.
A simple TCO view:
- Estimate total delivered energy over the life of the pack (kWh per day × expected days).
- Divide total cost of the pack (and installation) by that energy.
The result is a cost per delivered kWh. In many cases, the cost per kWh of LiFePO4 ends up lower than that of lead-acid, even though the first invoice is higher.
Compatibility checks before replacement
Before committing to a replacement strategy, always verify:
- Voltage and capacity – new packs must match the AGV’s electrical design.
- Physical fit – size, weight and mounting points must be compatible.
- Charger compatibility – existing AGV battery chargers may need new profiles or full replacement when moving to LiFePO4.
- Interfaces and communication – BMS communication (CAN, RS485, digital I/O) must integrate with existing AGV controllers and safety logic.
Working with a supplier experienced in AGV battery projects makes these checks faster and more reliable.
Upgrading to LiFePO4 AGV Batteries with SAFTEC
If your AGV fleet is approaching a replacement window, it can be more efficient to combine battery replacement with a technology upgrade.
A LiFePO4-based AGV battery solution can:
- Extend usable life to 8–10+ years in many operations
- Support multi-shift and opportunity charging without heavy degradation
- Reduce the number of times you must plan major battery replacements
- Improve uptime and reduce maintenance interventions
SAFTEC designs and manufactures 24 V and 48 V LiFePO4 AGV battery packs for warehouses, factories and logistics centers. For replacement or upgrade projects we can:
- Review your current battery type, runtime and age
- Estimate remaining life and potential benefits of LiFePO4
- Propose drop-in or custom AGV battery packs with matching BMS and charger options
- Support integration with your AGV manufacturer or system integrator
If you are planning a swap-out or modernization project, you can explore dedicated AGV LiFePO4 battery packs on your /agv-battery/ product page and discuss how to extend the life and performance of your fleet in the next upgrade cycle.
AGV Battery Life & Replacement – FAQs
How long do AGV batteries usually last in real projects?
In light-duty, single-shift applications, lead-acid AGV batteries often stay in service for around 4–5 years, while LiFePO4 packs can remain usable for close to a decade. In heavy 24/7 warehouses with high loads and short charge windows, those numbers can drop to 2–3 years for lead-acid and 6–8 years for LiFePO4. The more energy you cycle per day and the hotter the environment, the shorter the realistic lifespan.
What matters more for replacement: age in years or number of cycles?
You should look at both and use whichever reaches its limit first. A battery that is only three years old but has already seen very deep daily cycles may be closer to end of life than a five-year-old pack in light service. As a simple rule, if a pack is near the manufacturer’s rated cycle count or past the typical calendar life for that chemistry and you also see reduced runtime, it is time to plan replacement.
Is it OK to mix old and new AGV batteries in the same fleet?
Running different ages and chemistries in one fleet is common, but you should avoid mixing old and new batteries in the same vehicle or swap pool. When packs of very different SOH are swapped randomly, the weakest pack dictates performance and can be overstressed. Try to group batteries by age and condition, keep swap pools consistent and phase out the oldest group together.
How do charging habits affect AGV battery lifespan the most?
The biggest killers are chronic deep discharge, leaving batteries empty for long periods and charging at high current when packs are very cold or very hot. For better life, keep SOC in the middle band whenever possible, avoid “running to zero”, let packs cool before heavy fast charging and use charger profiles that match the chemistry. Opportunity charging with LiFePO4 works well because it naturally encourages shallower, more frequent cycles.
What should I budget for AGV battery replacement?
Exact prices depend on voltage, capacity and certification, but as a planning guideline many operators treat battery replacement as a multi-year capital expense, not a consumable. You can estimate a yearly budget by taking the purchase price of the pack, dividing it by its expected service years and then multiplying by the number of vehicles. Upgrading to LiFePO4 usually raises the first invoice but reduces the annualized cost once you factor in longer life and fewer replacements.
How much extra life can I expect when upgrading from lead-acid to LiFePO4?
In comparable AGV duty cycles, it is common to see LiFePO4 packs deliver two to four times the useful cycle count of lead-acid, especially when opportunity charging is used. That often turns a 3–5 year lead-acid life into 8–10 years of service for LiFePO4. The exact gain depends on how aggressively the AGVs are used and how well the charging system is designed.
How far in advance should I plan an AGV battery replacement or upgrade project?
A good practice is to start evaluation 6–12 months before you expect batteries to reach the 70–80% SOH range. That gives time to collect runtime data, review BMS logs, compare replacement options and, if you are considering LiFePO4, check charger compatibility and mechanical fit. With a clear plan, you can swap packs during scheduled downtime instead of reacting to unexpected failures.
