AGVs and AMRs both move materials around a site without a driver, but they do it in very different ways. That difference matters more than most people expect when it comes to specifying the battery.
The short answer: an AGV runs a fixed route on a predictable schedule, so its battery can be sized around a known duty cycle. An AMR decides its own route, so its energy demand varies shift to shift. The chemistry is usually the same. The sizing, the charging strategy and the packaging are not.
At Elite Battery Systems, we supply modular lithium-ion battery systems for both. Here is what actually changes between the two.
What is an AGV?
An Automated Guided Vehicle is a driverless vehicle that follows a fixed path. It uses guidance infrastructure built into the site, such as magnetic tape, inductive wire, floor-mounted QR codes or reflective markers. If something blocks the route, the AGV stops and waits.
AGVs are common in factories, warehouses and distribution centres for towing, pallet moving, forklift work and assembly line feeding. Because the route is fixed, the workload is repeatable and easy to measure.
What is an AMR?
An Autonomous Mobile Robot navigates using onboard sensors and mapping rather than fixed infrastructure. LiDAR, cameras and onboard computing let it build a picture of its surroundings, plan its own route and drive around obstacles instead of stopping at them.
AMRs are usually lighter than AGVs and are used where layouts change or where traffic is unpredictable. Order picking, goods-to-person fulfilment and hospital or lab logistics are typical.Why does the battery requirement change?
Four things shift once you move from a guided vehicle to an autonomous one.
The duty cycle stops being predictable. With an AGV you can measure a full shift and size the pack around it, with headroom for the worst day. An AMR covers different distances every shift depending on demand and floor traffic. That means sizing around a range rather than a single number, and building in more margin.
Charging becomes the robot’s decision, not the operator’s. Most AMR fleets charge autonomously. The robot returns to a dock when its state of charge drops below a threshold, takes a partial charge and goes back to work. That puts far more emphasis on partial charge cycles and on a BMS that reports state of charge accurately enough for the fleet software to trust it.
There is a constant base load. An AGV mostly draws power when it moves. An AMR’s sensors, cameras and onboard computer draw power whenever the robot is switched on, whether it is moving or queuing. That base load has to be included in the energy budget or the pack will come up short in real use.
Packaging gets tighter. AMRs tend to be smaller and lower, with the sensor stack and compute taking up space that would otherwise be available. The pack often has to fit an awkward footprint rather than a standard tray, which is where a modular or bespoke approach earns its place.
| AGV | AMR | |
|---|---|---|
| Navigation | Fixed route, site infrastructure | Onboard sensors and mapping |
| Obstacles | Stops and waits | Plans a route around |
| Typical payload | Higher, including tow and pallet duties | Lower to medium |
| Route changes | Requires infrastructure changes | Software update |
| Duty cycle | Predictable and repeatable | Variable |
| Charging | Usually scheduled | Usually autonomous docking |
Do AGVs and AMRs need different battery chemistry?
Usually not. Lithium iron phosphate (LFP) is the standard choice for both, and for the same reasons. It handles frequent partial charging without the damage that shortens lead-acid life, it delivers consistent voltage through the discharge, it needs no watering or equalisation, and it supports thousands of cycles.
Where lead-acid is still in service, the case for changing is stronger on AMRs than on AGVs. Lead-acid needs a cooling period after charging and is typically limited to around half its rated capacity in usable terms. Neither works well with a robot that charges in short bursts throughout a shift.
How do you size a battery for an AMR?
Start with the energy the robot uses, not the hours you want it to run.
- Measure or estimate the drive energy over a representative shift, including the heaviest realistic day.
- Add the base load from sensors, compute and any onboard equipment, across the full time the robot is powered on.
- Decide the charging strategy. Opportunity charging through the shift needs less capacity than a single overnight charge.
- Set a state of charge window. Running between about 20% and 90% rather than corner to corner extends pack life.
- Confirm the voltage platform and physical envelope against the chassis.
Get those five right and the capacity figure follows. Skip step two and the pack will underperform in service even though the maths looked correct on paper.
Can the same battery system cover both?
Often, yes, and that is the argument for a modular platform. Our standard packs run on 36V and 51.2V platforms and can be configured in different capacities using the same core system, so an operator running mixed AGV and AMR fleets is not managing two entirely separate battery estates, two charger types and two spares inventories.
Where the vehicles genuinely differ, we build to the requirement. Voltage, capacity, format, connector, communications and BMS configuration are all specified around the vehicle.
Frequently asked questions
Is an AMR just a newer AGV? No. They are different classes of vehicle. AGVs follow fixed guidance infrastructure. AMRs navigate independently using onboard sensors. Many sites run both.
Which is more energy efficient? It depends on the application. AGVs use less energy per unit of movement because they run a fixed, optimised path and carry a lighter sensor load. AMRs often use less energy across an operation because they avoid stopping and queuing.
Do AMR batteries need CAN communication? In almost all cases. The fleet management software needs accurate state of charge to decide when a robot docks, and that comes from the BMS over CAN.
Can I retrofit lithium into an existing lead-acid AGV fleet? Usually. The pack has to match the voltage platform, the physical tray and any ballast the vehicle relied on, and the charger has to be replaced. It is a routine conversion, but it needs specifying properly rather than treating as a like-for-like swap.
Do the same safety standards apply to both? Broadly, yes. Driverless industrial trucks are covered by ISO 3691-4 regardless of how they navigate, and lithium battery systems carry their own transport and cell-level requirements.
Talk to us about your fleet
Whether you are running AGVs, AMRs or a mix of both, we design and supply the battery system around the vehicle and the shift pattern rather than the other way round.
Contact Elite Battery Systems to discuss your requirement, or read more about our AGV battery systems and standard battery packs.