Got the Puma going in a 26 inch wheel with the 150V modified controller tonight was a blast and very quick, here is what I found.
On the flat it pulled very hard and fast right over 40mph and settled at 43mph on the flat! this seemed very fast, I was going past a lorry depot and had to back off fearing the weak breaks on the Raleigh would not stop me.
I ran out of town up a steep hill and it held 30mph! quite amazing, the motor was a little warm after all this blasting around I would say maybe 45 deg or so, this isnt unusual and about the operating temp of my USPD, the controller was warm but not hot I would say 35 deg or so.
Now I knew I was having too much fun! ha ha and sadly under hard throttle one of the Lipos hit its low voltage cut off and cut the power, the usual smell of burning silicon
been there seen that!! so I hooked in the flip top lipo and it all sparkled back in to life and I motored home at a more sedate 25mph! he he.
Mark is going to check with the supplier of the batteries but I think the old school Lipos (the ones that dont have the sep BMS) may struggle to cope if they hit LV cut off at 72V under load, its interesting as the new Flip top BMS was connected the both times I have blown a BMS and the new flip top BMS did not blow, its not too much of a problem as I have spares and will just fit the pack in to another box like on the other one.
The good news is it seems the controller mod is spot on and seems bullet proof, however I think at 72V I would limit the current to 20A with a Puma, with this in Mind it may be better to run a 20A controller at 72V, the Puma may take more but I think it may be pushing it, I have been running 1400 W for about 3 weeks, I will take the motor apart in a month to see how its holding up.
So in a nutshell its looking pretty good, the Puma is a flyer in a 26 Inch wheel at 72V, amazing hill climber and superb top speed, the modified controller should be good for 100V or so which is also good news.
Mark will be using the new Blue Lipo packs in the future though, they are more heavy duty and have better BMS, the flip top Lipos do seem to cope ok at 72V though something to think about if you intend to run 72V.
Such a lot of fun!!