Hi Guys,
I hope you are all well? Long time since I was here!
Well, my pie is still Flying. Nothing I do can kill it. And it still pulls me up any hill I can find. The acceleration is still fantastic. And even my ping seems to be still happy!
I have just hit 800 miles and I really don't get out on it much this time of year. My back tyre is badly worn, damn torque!
I would really love to run this motor @80amps. Only last time I tried that, I couldn't keep the front wheel on the road, so decided to go for 40 amps instead. I didn't want to pull the throttle on a hill and go flying back. With better weight distribution, I'm sure it wouldn't be a problem and @80 amps it's like a rocket! But in reality a 48 volt 20 amp ping is good for 2C continuous that's 40 amps! I would need a lipo pack for that rated for 4 or 5C and boy are they expensive.
Lipo is much safer these days I believe, but for some reason there seems to be no
BMS available for diy builds! It's smaller and lighter too, but with shorter cycles than LifeP04, but from what I have learned over at endless-sphere is, if you run your lipo to 80% DOD, they you can get well over 1000 cycles, provided of course you get a higher C than you will use!
So from my understanding of that (and I'm far from been an expert on batteries) is, If I want a 20 amp lipo, I really should get a 25 amp and leave 5 amps in reserve to massively prolong the life of the battery!
The Turnagy nanotech seems like really good stuff, however it’s not available in e-bike sized packs and you have to build them up yourself and charging them is a real pain in the ass, and again, there is currently no
BMS solution for lipo, that I am aware of and I really don’t know why. There are lipo packs you can buy for e-bikes from different sites, but they are ridiculously expensive! But it’s hard to find them! And they do actually come with a
BMS!
A 20 amp LiPo can cost 1200 USD! Even with 5C rating, that’s still insane considering it’s 300-500 cycles! The Ping battery is so much more better value even if it is 4kg heavier, so what? the rack can take it!
Anyway I am thinking I might say farewell to my Magic Pie in the spring or maybe summer as I really want a freewheeling gear motor. I believe them to be more efficient and they have better torque compared to direct drive at the same power levels. One fellow on the endless-sphere forum sells them fairly cheap and am considering getting it. Granted it won’t take the 40 amps, but I can limit that with the cycle analyst anyway. I just want the ability to cycle as much as I can without the damn drag of the pie and still have decent hill climbing and be able to go at 30mph!
Anyway I hope all your projects are running well? And no one has fallen off their bikes! ?
Mark