My Eplus project has progressed even farther.
Read my posts here in this thread on prevoious pages about converting my Eplus from NMH hub battery to LiFePo A123 20Ah 12S battery.
Such conversion has many benefits:

--- for close to same weight A123 pack has about 2,5 times more Wattshours of energy than hub battery
--- after getting rid of front hub you can have front disc brake installed.
--- even with double sealed Japanese bearings in hub rolling resistance of Eplus front wheel is greater than quality say Shimano hub.
--- A123 pack can be charged at rapid rate of 1C /my charger is 17A charger/ and after my average 10km ride I can recharge in less than 1 hour close to 45 minutes, not 4 hours.
--- regen is available right away
I ran many tests of my Eplus powered on A123 20Ah pack with empty shell front hub /NMH cells removed/ in my neighbourhood.
Difference was dramatic. Shortly .
Eplus on NMH hub feels strong and peppy during maybe first kilometer or two when is warm.
The problem is that NMH string of 30 cells starts sagging voltage very fast, this volage sag is detected by battery electronics and processor starts to limit power right away to protect/extend life of cells .
Powered by A123 20Ah powerfull cells Eplus feels strong for many kilometers. I rode 15kms in level 8 and still my Eplus felt peppy. I saw 1300W for the first time drawn by system when bike reached 50km/h repeateadly on its own, with peddaling /very fast one/ I saw 52-54km/h.
I never saw more than 1150W drawn on my Eplus with hub battery.
All this Eplus achived on 36V system, no need for crazy voltages here. It clearly shows how efficient Eplus bike is.
I am close to finishing A123 pack, see pictures.
Conversion electrically it is quite simple, you disconnect NMH 30 cell string , connect 12S lithium in place of NMH , tap 2 times 2S cells around 6.5-7V from A123 battery into DSP board of battery electronics and now system should power up normally.
In reality it is much harder with all this hardware , possibility of shorts and incorporating those 2 battery boards into your A123 battery.
SOC meter goes out of wack of course.
As we know Eplus batt electronics count charge going to and going out of battery and display on SOC meter.

With A123 connected it is tricky how batt electronics and particularly processor PIC18 would react, I managed to lock processor with one last SOC meter bar blinking and no matter what I do it stays that way which serves my purpose very well - regen is activated, throttle is active, everthing displays normally.

So I am finishing my A123 pack and on board charger.