60v hub motor, 52v28ah battery, 48v45amp controller

[CreativeSource]

Hi everyone
Please can anyone advise Me on the following. I have a 52v 28ah battery pack made up of LG MJ1 cells, with a 45amp BMS. a 48v 45amp sine wave 18mosfet speed controller, and a 48v 1000watt rear hub brushless gearless motor. I'm worried that this set-up is putting to much strain on the motor, so I'm thinking of upgrading to a 48v/52v 1500watt rear hub motor.
A. Would this be the sensible thing to do? Or am I safe has I am?
B. Or could I even go to a 60v 1500watt rear hub motor with My present kit?

Thanks so much for any advice you can give Me, I've just this week finished My build.

 

[SlowCo]

You should be fine as is. Only if you have the motor in a large wheel and have to climb very long hills the motor might overheat. Put in some ferrofluid / statorade to keep it cooler and/or check the motor temp in the beginning after your heaviest ride (low speed high amp climbs). What is the size of the wheel the motor is in? What are your climbing conditions and total weight?

 

[mat h physics]

There are better ppl to respond than me, though you've overlooked some basics.
The only thing restricting the motor voltage, is it's insulation. I doubt you want to go through the trouble of using a Mega-ohm meter, but it uses much higher voltage. Current will be restricted by heat capacitance and dissipation of motor and controller(watts).

Here is where the trouble may occur, the voltage max of the controller. If you can ID the components, make sure none of them are rated for less than 55V. Some components may have a tolerance listed, any borderline Voltages could be damaged.

If the controller has a low voltage cutout, the higher voltage battery may not be protected properly. Hopefully the BMS controls that function.

A properly sized resistor (rated for 45amps, in your case), in series with the controller, will reduce the voltage 'seen' by the controller. The draw back is lost energy potential, as the resistor burns power in the form of heat.

 

[CreativeSource]

Thanks for your replies
The bike's weight is 28kg and My weight is 180lbs, bike's wheel size is 27.5. I mainly ride flat areas and peddle hard and fast up hills, always keep the speed up on hills. I think I've discounted the 60v motor, but could you guys tell Me the pros and cons of replacing My 48v 1000 watt rear hub motor with a 48/52v 1500 rear hub motor, this is My preferred option. I always ride conservative, always peddle assist in setting 1-2 and only ever throttle flat out for no more than 10 seconds at any one time. With the 1500watt motor, is it possible to peddle along in maybe 3-4 power settings for longer, and throttle also for longer without to much overheating risk? I have a 52T chainring, so can peddle along quite comfortable at 30mph.

Thanks for any advice

 

[SlowCo]

If that is your use then you're fine and don't need to upgrade the motor. If you find the motor gets so hot you can't touch the cover for more than a few seconds just perform a reversed shunt mod. on your controller. By scraping of some metal of the shunt the max. amps that the controller will put out will be lower. Adding a Wattmeter in your wiring beforehand will show you the max wattage you use.

 

[2old]

IMO< as a non-expert, (as stated above) if your motor isn't getting hot you'll garner very little benefit from the 1500w one. If it's a little hotter than "acceptable', consider Hubsinks or Statorade.

 

[999zip999]

If the motor is running ez . like on a flat road. The motor runs fine . In soft sand or a hill starts to stall the motor the motor heats up fast. Or with regen and wot starts. Get your hand out and put on motor if hot you will know it.

 

[CreativeSource]

Thank you all so much for your time and sound advice, you've saved Me a tidy sum now I'm keeping My 1000watt motor. Again, thanks guys