Why a capacity rating cannot promise a full shift
A battery mining locomotive's capacity describes stored electrical charge under stated conditions. Runtime describes how long it can perform a particular job before reaching an agreed stopping point. Connecting those two quantities requires a duty profile: what the locomotive pulls, where it travels, how often it starts, and how much time it spends waiting.
That distinction matters when comparing quotations. A larger Ah number does not, by itself, establish more productive hours. Nor does a five-hour capacity rating promise five hours of haulage. For a useful comparison, ask each supplier to work from the same route and shift assumptions, with the battery configuration identified. The CTY12 and CTY5 documents illustrate why even apparently straightforward specification tables need careful reading.
Read Ah together with its discharge rate
Ampere-hours combine current and time. Under an ideal constant-current calculation, 500 Ah divided by 100 A gives five hours. That arithmetic explains the rating relationship; it does not establish locomotive runtime. Victron's battery-monitor documentation explains that available capacity depends on discharge rate, with lead-acid batteries more affected by this relationship than lithium batteries.
A separate manufacturer example makes the labeling issue visible. Trojan lists its T-605 flooded lead-acid battery at 175 Ah over five hours and 210 Ah over twenty hours. Both values describe the same product under different discharge rates. This is an example of rating conventions, not a proposed battery for a CTY locomotive.
The supplied CTY12 locomotive table lists 500 Ah at the five-hour rate. Its attached battery sheet instead labels 500 Ah at 0.3CA. Preserve both descriptions when requesting clarification: they are different stated test rates. Ask for the applicable test report, including current, temperature and end voltage, before comparing the figure against another pack.
Victron: battery capacity and discharge rate ↗
Voltage adds the energy context
Ah alone leaves out voltage. A first nominal energy calculation is voltage multiplied by Ah, divided by 1,000 to express kilowatt-hours. Using the CTY12 document's 192 V and 500 Ah gives 96 kWh as a calculated nominal figure. It is not a measurement of energy available at the wheels or a guaranteed usable battery capacity.
The CTY5 document needs a different treatment. Its locomotive table gives 90 V, while the attached pack sheet gives 96 V and capacity of at least 330 Ah. Those voltage entries remain unresolved. Combining whichever figures produce the more attractive comparison would hide an important configuration question. Request confirmation of the specified pack and its compatibility with the locomotive electrical system.
Even after nominal energy is confirmed, a runtime estimate still needs the usable energy window and average demand. Specify the measurement boundary: battery-terminal energy and traction-motor output are different quantities. A calculation that mixes those boundaries without accounting for losses can look precise while answering the wrong question.
Continuous current and peak current answer different questions
Both supplied battery sheets list 200 A continuous discharge current and a 400 A peak limited to twenty seconds. The peak value is a short-duration rating; it cannot replace the continuous figure in a sustained-duty assessment. These are document references for the described packs, subject to confirmation for the ordered configuration.
Procurement teams should request a load profile that shows both sustained demand and short peaks. An average can conceal a repeated high-current section, while a peak alone says little about total shift energy. Ask the supplier to explain how the proposed pack, controller and traction system match that profile, including any applicable time limits.
Do not divide nominal energy by the sum of the motor nameplate powers and label the result working time. The nameplates do not describe average battery input over a mine route. They also do not account for waiting periods, changing traction demand or auxiliary consumption. Measured cycle energy is a better starting point when comparable operating data exist.
Build runtime around a defined transport cycle
A useful runtime request starts with a repeatable cycle: departure, loaded travel, unloading or handover, return travel and waiting. Record distances, grades, curves, train mass and the frequency of stops alongside the schedule. Keep the locomotive's own mass separate from the cars and their contents. In the CTY12 source, 12 t is adhesive mass, not a twelve-tonne payload rating.
For an engineering estimate, the supplier needs battery energy consumed per representative cycle and the agreed usable energy available. Dividing usable energy by cycle energy can estimate cycle count, provided the operating assumptions remain valid. Converting that count to elapsed hours then requires cycle duration and the treatment of idle demand.
Ask for the evidence behind each input. A logged trial on a comparable route is different from a simulation or a preliminary assumption. Require the estimate to identify which it uses, and record the condition of the battery used for any trial. This makes later acceptance discussions specific: the parties can compare the delivered result with the same defined duty.
Charging time and temperature belong in the shift plan
The CTY12 battery sheet states charging current up to 200 A and approximately 2.5 hours charging time. The CTY5 sheet states 100 A and approximately 3.5 hours. Those times should remain approximate document values. Neither sheet, as extracted, establishes a complete shift turnaround promise with every starting and ending condition specified.
Request the assumed initial and final state of charge, charger specification and temperature conditions behind the quoted duration. Also separate the time on charge from the total time until the locomotive is available for its next assignment. That wider schedule may include travel and other site activities, which need their own allowances.
Temperature envelopes must stay attached to the component they describe. The CTY12 machine document gives −20°C to 40°C, while its battery sheet gives 0°C to 45°C for charging and −20°C to 55°C for discharge. The CTY5 battery sheet gives 0°C to 45°C charging and −20°C to 60°C discharge. These limits do not establish equal capacity throughout each range.
What to ask for in a runtime quotation
Send the supplier one route description and one shift schedule, then request a configuration-specific response. It should identify the pack, clarify conflicting voltage or capacity-rate entries, state the usable energy basis and show how cycle demand was established. Include the charging assumptions alongside the runtime calculation so the transport schedule can be reviewed as a whole.
The battery mining locomotive range page provides a starting point for equipment discussions. For a runtime assessment, add the train details and route profile to that inquiry. A statement tied to those inputs is more useful for procurement than an unqualified number of hours beside a battery capacity.
Frequently asked questions
Does a 500 Ah five-hour rating mean five hours of mine haulage?
No. It describes capacity at a stated discharge rate. Haulage runtime depends on the actual duty, usable energy window and operating conditions. The CTY12 documents also use a separate 0.3CA capacity label, which needs clarification.
Can CTY5 runtime be calculated using 96 V?
The supplied pack sheet states 96 V, but the locomotive table states 90 V. Confirm the intended configuration before using either value in a procurement calculation. Voltage and Ah still cannot establish runtime without demand data.
Does the six-hour REST TIME entry mean six hours of operation?
No supported operating-time interpretation is available from that entry. It should not be used as runtime, a charging interval or a shift guarantee. Request a definition from the supplier if it affects the proposed schedule.
Related equipment
References
Victron Energy BMV-700 manual, battery capacity and Peukert exponent ↗