mpbarrett

I started this, and I am still listening, but am almost afraid to post any more comments or to have an opinion on this thread... ;( mike

sorry I am not making myself very clear... The when the drive cuts out the current does drops to zero. I will set it up in the garage today and directly monitor the battery current and voltage. I am a retired professional electronic engineer with (30 years designing and building electronic system for a oil field research company) with a very well equipped garage Does anyone have cct diagram for the 806SE control system? BTW thanks everyone for all the helpful comments. regards mike

sorry I did not mean to upset you, put it down tot he heat... mike

That's not correct what you are suggesting is that as the speed increases the power (I*v) goes down that's just not possible otherwise you could reach a terminal velocity using no power... I understand that the power will be limited at 15 mph to ensure the speed doesn't exceed the legal limit. But that is not what happens. Above 13mph when the current display goes to maximum the drive then stops no further assistance, once the speed has reduced to less than maybe 8mph and a period of time has passed then the power comes back on again. It feels like something is current limiting, rather like a thermal cutout that them takes a period to reset. I will try to get some current measurement data from the system once the weather has got s bit cooler, 100f in Cambridge today. Regards Mike

That's interesting have you found a solution to it? Mike

Sorry the motor cuts out when the current goes high as the speed increases. Usually above 13mph drive doesn't come in again until the speed has dropped. Need to test it again to fully understand what's happening... Thanks mike

I mean the current read out on the display. The power goes (no drive) after the current reading has gone up to maximum (5/6 blobs). regards mike

I have brought a second hand Wisper 806SE. I knew when I brought it that the battery had failed (reading less 10V..) and before buying a new Wisper battery I have tried running it on a new 36V 10A battery pack brought from Ebay. I want to decided whether I like it if I do then I will buy a new battery for the Wisper and use the new Ebay battery pack on another bike I want to try to convert. The bikes works but seems to have strange problem. If I run it and either use the throttle or pedal assist once the current reading goes to maximum then the assist stops until the speed has dropped. This seems to happen above >13mph.If I keep the current below maximum its all fine and works. It feels like there is a current limiter that's tripping in and then resetting. I assumed that this must be an issue with the cheapo battery pack I am using, but the voltage from the pack does not go to zero so I don't think the battery pack itself is current limiting. Does the control system on the Wisper itself have a current limitation that might be cutting in? Any ideas welcome, I am new to electric bikes but have a background in electronics so am happy to play with the power system (and am very aware of the risks of playing with Li-ion batteries). BTW the bike is very impressive, beautifully made and designed. mike