The 7245 is rated for 450 amps for 2 minutes, while the 4844 is only rated for 400 amps for two minutes, where you will notice it is once you get past the 300amp 5 minute rating of the 4844 is that it's only rated for a sustained 1 hour rating of 150 amps while the 7245 can sustain 200 amps for an hour, that extra 50 amps in that 5 minute to 60 minute time frame is a 25% drop in power, with my 4865 speed controller I've felt it drop from it's 400amp output to 250 amp output, so I'm not sure what having it drop down to 150 amp output would be like but it would make going up hills a rather slow event.
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