Ok almost there a bit of tidying up to do plus decide what battery I need.
For tests I am using this battery. Fits in a pencil case. Made up of two series 5s2p packs connected in series with balance taps and fuse giving a total of 36v, 3Ah using 1.5Ah Sony Konion cells. Weighs 1kg.
I also have a 36v, 6.0Ah pack made of the same cells as well. Max current draw should not exceed 20A for the smaller pack and 40A for the larger one. Note the date (6/13) this is now 4 years old and done thousands of miles, though that is with my Brompton pulling no more than 8-10A max (usually about 3-5A) its hardly been hammered. It doesn't have a BMS but has taps as I said for balancing. I doubt I have balanced it more than 3 times in its life time. I never charge beyond 41V i.e. 4.1V/cell.
You can now get these cells in 3.1Ah capacity and I am thinking about building a 10s3p pack later. These new cells can cope with 30A draw over the 10A draw of the above cells.
Going out on the flat I have done a few tests to see how much current I am drawing:
1. At setting 3 I draw no more than 6A and it easily accelerates me up to 15mph
2. At setting 5 I draw around 17A but it accelerates me quickly up to 19mph!
I am really rather pleased with this setup though need to go find and test it on some hills lol.
I have put the controller in a project box as shown below. I could probably put it in a smaller box but this one allows me to coil up the cables and not cut any of them. I may do that later.
I have some ideas for a better arrangement to carry the battery (its carried in the pannier at the moment) so will post more later.
Its been such fun building this especially as it is different from my usual small wheeled, light bike front hub builds. Also my first rear motor conversion. I must admit I quite like the power up back and of course there is no weight on the front steering found with front hub conversions.
