Cyclone Current Draw?

[Freddyflatfoot]

Hi,
Posting on behalf of a mate.
He has a Cyclone motor (unknown wattage), with a 24v/10AHr LiFePo4 battery.
He is telling me that the battery goes flat fairly quickly, and without warning. He says that he can have all the lights on his throttle, and then it will just go 'dead'. (He is hitting the LVC)
My understanding of the Cyclone motor, is that it will draw as much current as it wants? i.e., there is no current limiting in the controller?
If that is correct, is there any way that a shunt can be added to the motor to limit his current draw to say 15A?
That would also be kinder to his LiFePo4 battery, to limit the current draw to 1-1.5C.
He really only has the motor for assist on his tandem, and his wife has control of the throttle! Apparently she only knows one setting, guess what that is?
Anyway, any help or advice would be appreciated,
Thanks.

 

[rkosiorek]

my 500W Cylone draws peaks of 37-40A.

that would be 4C. it is also why the cells that Cyclone sells and recommends will deliver the 4C rate. they use the PSI/LifeBat/Yessa 40138 cells in thier packs. it is also why they do not recommend the NiMh batteries or cheaper LiFePO4 batteries as most of these are only good to 1.5C.

rick

 

[cerewa]

run longer wires, (to the front of the tandem) and go light on the throttle.

I didn't realize there was no currentlimit in the cyclone controller.

I used a 1c-rated 24v10ah battery with my cyclone and never tripped the 20-amps bms current limit.

But this is using the motor as assist only, on a light ebike with a 130 pound rider.

Go easier on the throttle and use a low gear and you'd still be able to keep below 20 amps on a tandem. If you pedal at a good cadence, maybe 80rpm or so, the motor will not be able to draw more than 20 amps at full throttle due to "back emf".

just something to keep in mind : 20amps / 24volts is 480 watts, which (I'm told) is more power than two cyclists can put out continuously, unless they're in pretty good shape. A 100% boost in power is nothing to sneeze at.

 

[rkosiorek]

it seems that the actual absolute current limit for the 500W system is closer to 35-40A and would be set by the controller. i have never seen it go higher than that.

on the same bike (a real EV Warrior) using the original motors and the same batteries i have seen the current go up to 100A on the CA meter so i know the batteries are capable of supplying a lot more power.

rick

 

[Diamondback]

on my cyclone 500w i have seen peaks of 44A on the cycle analyst.

it usually stays around the 25A - 32A range though.
if you read the info on the cyclone-tw.com page, it says there that you must install 35A fuse on the battery to protect the controller.
so that (to me anyway) says that their controllers do not have a current limiter built in...

i am planing on using my CA to limit the current to 35A just to be on the safe side.....

Jason.