BACKGROUND Technical Field The invention includes embodiments that relate to a thermal management system for use in vehicle, the vehicle having the system, and an associated method. Discission of Art 'Ilie engine coolant temperature of a haul tiiick or dumper has traditionally been controlled by a radiator fan that is mechanically linksd to an output shaft of the engine. Tn particular, the radiator fan can fee linked to the engine via a hell and dutch mechanism. The clutch is able 10 spin the fan at a desiTed fraction of engine speed, as dictated by a controller. At full engine power, the radiator fan cart run at its full speed to provide cooling to she engine. Running the cooling system comes at a fuel cost and power cost. Accordingly, cooling systems today minimise fuel consumption by picking an operating temperature that is as high as possible, and then maintaining that high temperature using the minimum cooling necessary. Therefore, it may be desirable to have a vehicle and/or system with properties and characteristics that differ from those properties of currently available vehicles and systems. H may be desirable to have a method that differs from those methods currently available. BRIEF DESCRIPTION in an emi>odiment, a thermal management system (e.g.s for a vehicle) includes a cooling system for cooling an engine: a plurality of energy sources, and a controller. The cooling system has a first electric device that is controllable independent of engine operating speed. (Meaning that the first electric device of the cooling system 2. is not mechanically driven by the engine and that the speed of the first elecmc device is not lied lo ihe speed of the engine.) Each of the plurality of energy sources is controllable lo supply electrical power to the cooling system. The controller is operable to select a. first energy source from among the plurality of energy sources and to direct the electrical power From the first energy source to the cooling system for operation of the first electric device. The first energy source is selected based on at least one of an availability of the first energy source and;or an energy cost factor associated with the first energy source supplying the electrical power, f"First" is simply a designation to differentiate one member of a class of elements from other membeis in me class, and is not meantto denote an order or position.) to another embodiment, a method is powered (or the cooling system may be otherwise powered) to cooi a cooling element 120 associated with the engine 104. "Cooling element" refers to a portion of the engine thai is cooled, or an element that is cooled to in turn cool a ponion of the engine. In regards to the former, one example of a cooling element may be an engine manifold (e.g., exahattst or intake manifold), or an engine block or portion thereof, hi regards to the latter, one example of a cooling element 120 is a cooling fluid (a. coolant such as water mixed with antifreeze) in a fluid circuit 122 associated with the engine 104 and coolmg system 102. Another example of a cooling element 120 is cooled air that is blown onto or into me engine for cooling purposes, hi the case of a cooling fluid in a fluid circuit 122s the fluid circuit may comprise a cooling fluid reservoir, cooling jackets around an engine block, a water pump, valving or other control elements., a. radiator, and tubing/hoses for fluid interconnections. Thus, a radiator ian motor 118 may be electrically powered to drive 8 radiator i\m 1U> for blowing air across or 7 through the radiator. for heat exchange from the cooling liquid to the air, and thereby cooling ihe coolingliquid. According to one aspect of Ihe invention, the cooling system J.U2 may be operated in an overcooling mode of operation. In the overeoolmg mode of operation, instead of maintaining Ihe temperature of a cooling element (e.g.. cooling fluid, or engine or vehicle components) at a designated maximum threshold temperature, the cooling element is cooled to a low temperature within an acceptable temperature range, using relatively ilU>w cost" electrical power. The low cost electrical power may be provided from a first energy source 106a having a lowest energy cost factor 11'4 among available energy sources 106. In one ©sample, such a first energy source 106a is a dynamic braking system. Overcooling a cooling element wiH. delay the need for cooling when low cost electrical power is no longer available, such as when motoring, effectively resulting in additional traction power available during that period and a lower overall load factor. In an embodiment, therefore, with reference to FIG. 2, in a thermal management system 200, a controller 108 is operable to direct electrical power 112 from a first energy source 106a to a cooling system 102 for operation of the cooling system 102 in an overcooling mode 124. (Although plural energy sources are shown, it may be Ihe case that tlse system only has one energy source.) In the overcooling mode 124. a first electric device 110 of ihe cooling system 102 is powered to continue to cool a cooling element 120 from below past a designated maximum threshold temperature T3 (see point or region 126) lo a lower, second threshold temperature T5. (As explained above, the cooling element 120 is associated with the engine i0~U To explain further, FIG. 2 shows a hypothetical graph illustrating an example plot of temperature T (y-axis) versus time t (x-axis) for a cooling element 120. That is, the graph shows how the temperature T of the cooling element 120 varies over time t, in several possible operating modes of ihe cooling system in the thermal management system. In the graph, Tl represents a minimum allowed temperature- of the cooling element and T4 a maximum allowed temperature of the cooling element, in between which is an allowed temperature range of the cooling element. Tl and 7'4 may be designated levels, and'or they may represent physical limits of the cooling 3" element (such as a freezing point and point where damage may occur, respectively). In a time period prior to tl. the temperature of Ihe cooling dement is rising, tor example, due to engine operation. Temperalure T3 represents a designated inaximum threshold temperature. The designated maximum threshold temperature T3 is the designated temperature at which operation of (he cooling system is initiated in order to prevent (he cooling element from overheating (e.g., reaching or approaching close to the maximum allowed temperature T4. Thus, before time tl. the cooling system is deactivated (or at least not powered sufficient to prevent the temperalure from increasing}, and at time tl, corresponding to temperature 13. the cooling system is activated for cooling the.cooling element 320. Between time tl and lime t2, the temperature of the cooling element may continue to rise due to lag time from when the cooling system is activated to when the temperature of the cooling element drops. However, the temperature of the cooling element eventually falls, reflecting thai the cooling system is acting to cool the cooling element (e.g., even though the cooling element may ccnlinue to receive heal energy from the engine or otherwise, the cooling system acts to lower the net energy level of the cooling element) At time • 0.2OR). In other embodiments, again depending on cooling system fO characteristics, the predetermined minimum threshold temperature T2 is at or within five to len percent, or ten lo fifteen percent, or fifteen to twenty percent, of the allowed temperature range of the minimum allowed temperature TI. In FIG 2. the second threshold temperature T5 is illustrated as coincident with the predetermined minimum threshold temperature T2, which is above (he minimum allowed temperature Tl. Thus, in the overcoojing mode 124. subsequent lo time t2, die cooling system 102 is powered to continue to cool the cooling element 120 from below past the designated maximum threshold temperature T3 lo the lower, second threshold temperature T5, which in this example is the predetermined minimum threshold temperature T2. Once the temperature of die cooling element reaches the second threshold temperature T5 (the predetermined minimum threshold temperature T2) at time 13, the cooling system is deaciivated/de^powered. allowing the cooling element temperature to rise (possibly after a lag) due to continued operation of the engine. In another embodiment., with reference lo flG. 3, in the overcooling mode 124, a first electric device 110 of the cooling system 102 is powered lo continue Lo cool a cooling element 120 from below pasta designated intermediate cycle threshold temperature T6 (see point or region 126) to a lower, second threshold temperature TS. (The designated intermediate cycle threshold temperatafe T<5 is above the second threshold temperature T5 and below the designated maximum threshold temperature T3: thus, continuing to cooJ a cooling eiemenl 120 from below past a designated intermediate cycle threshold temperature T6 is a gpeeies/vanant of continuing to cool the cooling element from below past a designated maximum threshold temperature T3.) To explain further, in this embodiment, in a first mode of operation 128, the cooling element 120 is maintained ai the designated maximum threshold temperature '13 durmg operation of an engme of the vehicle. Here, '"maintained at" more specifically refers to cycling the cooling element temperature around the designated maximum threshold temperature T3 and around the designated intermediate cycle threshold temperature T6. Thus, the designated maximum threshold temperature T3 acts as a trigger for activating the cooling system, and the designated intermediate cycle threshold temperature T6 acts as a trigger for deactivating the cooling system. // Specifically, when the cooling element temperature fails below T6 (lime t3), the cooling system is deactivated (not powered), and when the cooling element temperature rises above *D (time il>. the cooling system is activated (powered). In the overcoming mode of operation, instead of deactivating or de-powering the eoofing system when the cooling element temperature fails below T6 (time t3), the first electric device 110 of the cooling system 102 is powered to continue to cool the cooling element Ut) -from below past T6 to a lower, second threshold temperature T3. The embodiment of FIG. 3 illustrates that a firm, "regular" (or otherwise) mode of operation 138 may be more complex than simply cycling the cooling system 102 oil and oft' around a single temperature point T3. Thus, regardless of how a cooling system is cycled in a first mode of operation, the overcooling mode presides a mode- of operation for continuing to actively cool a cooling element (e.g.. by electrically powering an electric device of the cooling system) below the lowest point of the first mode where active cooling is maintained. Further in regards to the embodiment of HG. 3, a thermal management system may comprise a cooling system for cooling an engine, one or more energy sources each configured to supply electrical power to the cooling system, and a controller. The cooling system has an electric device that is controllable independent of engine operating speed. The controller is operable to direct the electrical power from at least one of lite oue or more energy sources to the cooling system for operaiion of the cooling system in a first' mode of operation and in a second, overcooHng mode of operation, in the first mode of operation, the electric device is not powered to coo! a cooling element (associated with the engine) any lower than a first threshold temperature. In the overcoohng mode of operation, the electric device is powered lo continue io coo! the cooling element below the first threshold temperature to a lower. second threshold temperature. In a specific example of overcooling, a thermal management system includes a cooling system 102 for an engine 104. a dynamic braking system 106a, and a controller 108. Ihe cooling system 102 includes a radiator fan motor 116 and a radiator fan 118. The radiator fan motor 116 is coupled to the radiator fan 118 for driving the radiator fan 118. When the radiator fan is driven, it cools a cooling fluid fZ_ 120 in a fluid circuit 122 associated with the engine 104 and cooling system 102 (e,g., in conjunction with a radiator). The controller 108 monitors the dynamic braking system I06a, and when electrical power i 12 is available from she dynamic braking system 106a, the controller I OS directs the electrical power 112 from the dynamic braking system 106a to die radiator fan motor 116, for overcooling the cooling fluid 120. Thai is. the Tadiator fan motor II6 is powered to cool the cooling tluid 120 from below past a designated maximum threshold temperature T3 (FIG. 2). or from below past a designated intermediate cycle threshold temperature T6 (FIG. 3}, or otherwise below past a lowest temperature at which active cooling of the cooling fluid is continued w one mode of operation 12S. to a lower, second threshold temperature T5. The second threshold temperature T5 may be a predetermined minimum threshold temperature. T2 of the cooling fluid. In an embodiment, one of the energy sources 106 is an energy storage system having one or more energy storage devices. The energy storage device may be pre-charged (that is charged when the vehicle is parked and able to connect to a charging station), or il may be charged during operation of the vehicle, such as by receiving electrical power from an engine alternator system, or from an external source (e.g.. catenary line or 'third' fair-type device), or from a dynamic braking system, ox from other charging means (eg., scavenging elecricity from a Utrbocharger). If a vehicle lias a dynamic braking system, the energy storage device may be electrically coupled to the dynamic braking system, and the energy storage device may be operable to supply electrical power from the dynamic braking system to a cooling system electric device in response to a signal from a controller (regenerative braking). Thus, similar to as previously described above, when dynamic braking energy is available (from the energy storage device or directly), the system will cool a cooling dement (e.g., cooling fluid, or engine part or other vehicle part) to a low temperature within an acceptable temperature range. This will delay the need for cooling when dynamic braking energy is no longer available, such as when motoring, effectively resulting in additional traction power available during that period and aloweroveralHoad factor. A suitable storage system can include a variety of energy storage devices. A suitable energy storage device may include, for example, a sodium metal hab'de \Z battery. sodium sulfur. lithium ion battery, nickel metal hydride, mckel cadmium, and the like, as well as oilier energy storage mediums such as capacitors, fuel cells, fly¬wheel devices, and She like. While the energy storage devices listed here may not be entirely interchangeable in all circumstances, they may be selected based on the end use requirements and constraints. In another embodiment, with reference to FIG. 4. an over-cooling mode of operation is initiated .for precooling purposes. Here, a thermal management system 300 includes a cooling system 102, an engine 104. one or more energy sources; KX>r and a controller 108. Overall arrangement and operation is simitar to what is described above in regards to one or more of FIGS. \-i. However, the controller 108 is additionally or alternatively configured to identify a time period 130 preceding a load "W of the engine or vehicle exceeding a designated load threshold "Ml," based on a learned duty cycle 132 of the engine. Further, an overcooling mode of operation (such as described above) is initiated during the time period 130. To explain further, in the thermal management system 300, the system anticipates periods that precede heavy engine load portions of the haul cycle, and precools the engine to delay the need for cooling during the heavy engine load portions. For this purpose, the controller 10K has information about a learned dutv cycle 132 of the engine, foa very simple example, a teamed duty cycle is simply a measure of engine/vehicle load as a function of lime during a cycle of operation. where the cycle is repeated and the measure of load is thereby applicable across multiple repeating cycles. (An example is a haul truck wherein for each cycle of operation, the haul track runs the same route and performs the same tasks.) In more complex examples, the learned duly cycle incorporates additional factors besides load and time (all factors referred io as *TS in the graphs of FIG. 4), such that load levels can be anticipated not only as a function of time, but also of current vehicle operating conditions/parameters. Methods for generating learned duty cycles are known in the art. For example, see U.S. Pat. No. 6601442 to Decker e? ai. Tn the thermal .management system 300, the controller 108 is provided with datii/mformsrtion of the learned duty cj-cle 132. lire data-'information may be loaded into the controller 108 (e.g., into controller-accessible memory) in advance of vehicle \h operation. Alternatively or additionally, the controKer 108 may be configured to generate a teamed duty cycle 132 by monitoring or measuring vehicle operations and processing data of the monitored or measured vehicle operations according ip a designated method fox generating a learned duty cycle 132_ In either case, during vehicle/engine operations, the controller 108 identifies a time period 130 preceding a load M of the engine or vehicle exceeding a designated toad threshold Ml. The time period I3t> is identified based on (i) the teamed duty cycle 132, and eriod preceding a load of the engine exceeding a designated load threshold, based on a learned duly cycle of the engine: and the overoooling mode is initialed during the time period- 7. The system of claim 2, wherein: the controller is configured to determine a heat rejection rate between the cooling system and an external environment based on one or more characteristics of the cooling system and one or more conditions of the external environment; and tfie controller is configured to disable Ihe overcooling mode when a cooling cost of cooling; the engine is above a designated cooling cost threshold; the cooling cost being deterniined based at least in. part oh the het& rejection rate. 26 &. The .system of claim-1, wherein the cooling element is a cooling fluid in a fluid drcuii associaied: with the engine and cooling System. and the characteristics of the cooling system include a ffpe of the cooling fluid, a volume of the cooling fluid, a flow rate of the cooling fluid, an age and/or history- of the seeling fluid, and/or one 0* more characteristics of a radiator portion of the cooling system. V. The system of claim L wherein: the controller is configured to determine a heat rejection rate between the cooling system and an external environment based on one or more characteristics of the cooling system and oneor more conditions of die external environment; and tine controller is configured to control ihs cooling system based on ihe heat rejection rate. 10. A method, comprising: switching a cooling system of a vehicle from a first mode of operation to a second, overcooling mode of operation; in lite first mode of operation* maintaining a cooling element at a designated maximum fee&hoid temperature during operation of an .engine Off the vehicle, therein the cooling efem&H is associated with Ihe engine; and in the overcooling mode of operation, powering the cooling system to cool the cooling element from past below the designated maximum threshold temperature to a lower, second threshold temperature. 11. fhe method of claim ML wherein the cooling element is a cooling fluid in a .fluid- circuit associated with the engine and cooling system* and wherein the second threshold temperature is a predetermined minimum threshold temperature of die coolmg fluid. -2 7 12. The method of claim it), wherein the step of powering me cooling system in the overcaolJng mode comprises dimming electrical po^^r from adynamic braking system of the vehicle Lo Ihe cooling system 13. The method of tlaim 12, further comprising; determining when the electrical power from the dynamic braking system is available; and iniligfiing the overeoolmg mode when the eiectriesl power from the dynarnie braking system is available 14. The method of ejaim 10, further comprising: selecting a first energy source of the vehicle for powering the cooling system m the orereooling mode, the first energy source being selected from among a plurality of energy sources in the vehicle, and th^ first energy source being selected based on at leasi one of an availability5 of the first energy source and/or an energy cost factor associated with the first energy source powering the cooling system. 15. Trig memod of claim 10, further comprising: identifying a time period preceding a load of the engine exceeding a designated load threshold* based on a teamed duty cycle of the engine; and initiating the overcooiing mode of operation during the time period- Id. The method of claim ID: further comprising: for one or more energy Sources of the \ehiele available for powering the cooling system, assessing one or more energy cost factors respectively associated with the 0.n& or more energy sources', and j?e precluding switching to the overcoming mode of operation if none of the one or wore assessed ener^ -cost factors is below a designated cost threshold. 17. The method of claim 16, further comprising: identifying a first; assessed energy cost factor of the one or more energy cost factors that is iowesi below the designated cost thresholds aid powering the cooling system in the overcooimg mode of operation using a first one of the one or more energy sources thai is associated with the first assessed energy cosl factor. 1&. A vehicle, comprising: an engine; a cooling system for cooling the engine, the cooling system having an electric -device that is controllable independent of engine operating speed; a first energy source configured to supply electrical power to the calling system; and ■a controller that is operable to direct the electrical power from ihe first energy source to the cooling system for operation of the cooling system in an overcooUng mods, wherein in the overcoming mode the electric device is powered to continue to c&oi a coofihg element from below past a designated maximum threshold temperature to a Sower* second threshold temperature, wherein the cooling element is associated with die engine. \9. The vehicle of cMui IK, wherein: the electric device of the coaling system comprises a radiator fan and a radiator fan motor coupled to the radiator fan for driving the radiator "fan, and the cooling element' is a cooling fluid in a fluid circuit associated with die engine and cooling system: ^ the first energy source is a dynamic braking system configured to supply (he electrical power lo (he radiator fan motor during a braking event; and the controller is operable to direct the electrical povver from the dynamic braking ostein to Ihe radiator fan motor lo coo! the cooling fluid to tits second threshold temperature. 2ft. The vehicle of claim 19, therein the second threshold temperature is a predetermined minimum threshold temperature of {lie cooling fluid. 21 The .vehicle of claim 19, wherein ihe second threshold temperature is a lowest ternperanire to which the cooling fluid is cooled in the vehicle out of all operational modes of the vehicle. SSS^ropcrty Practice 709 710;ToUtoyHouse. 15Il7