New Ebike user, with need of battery info and opinions

[Diamondback]

the pictures.....

the cells are not just held together by the threaded ends. they are locked into the fibreglass end plates, and each cell is
hard up against the one below/above so i can't see any way that they could move about.

Jason.

 

[Robbie Hatfield]

Expect contact failures and arcing between cells. The loads presented by an ebike require better cell interconnections than that of a 5 and dime flashlight. LOL


It might be funny if your power cuts out in the middle of a busy intersection though.. LOL

Robbie

 

[Ypedal]

the thin wires are only for the BMS. i expect there are thick copper tabs for the discharge connections... :wink:

That pack needs to be boxed btw.. !!

 

[Diamondback]

there are copper plates for the cell inter connects bolted behind the fibreglass sheets.

there will be no problems with current draw at all !

i will take advice from ypedal and hot melt glue them together, so that there is no movement.
also, the pack (as pictures) was removed from the protective bag for the pictures.

in use, it will be in that bag, and a second bag on the bike that will be lined with high density foam.
should be more that well protected.....

Jason.

 

[etard]

Any updates Jason? What do you plan on doing with your NiMH battery and charger? Is there a weight savings with the lithiums?

 

[Diamondback]

no updates yet. I'm at my parents place for a few days for Xmas.
I won't get a chance to try the pack untill Saturday.

I have to change the plug to an Anderson type, and hot
Glue the cells together (as per ypedal's recommendation)

I plan to list the nimh pack & charger on eBay once I'm
Certain that the new pack is good.

Hopefully I don't loose too much money on it.
Though I can't see me getting more than 50% back...

I'll post again once I have had a chance to test it out.

Jason

 

[Diamondback]

finally, an Update

i have just about finished the building of the new battery box for the LiFePo4 pack.
i could not find a big enough bag, so i cannibalised the old Topeak bag for its quicktrack
slide on mechanism, and build a MDF box for the new pack.

i will finally get a chance to test the new battery on Tuesday, and i have listed the old
near new NI-Mh pack & charger on ebay. the listing starts at 7.30pm AEST Monday.

for those that might be interested, the pack is one from ebike.ca (24V 18A Ni-Mh)
has only 8 cycles on it, and has never been below 65% DOD.

item number is 200295113442

the battery is probably only good for Australian buyers,(due to shipping costs)
but if anyone really wants it, (and your willing to pay the freight costs) ill ship just about anywhere.

ill post pictures of the new battery box and the test ride results later this week.

Jason.

 

[recumbent]

Good to see you bought top tier batteries for your bike, now hurry-up and test the system for range, and speed, so those of us in the northern hemisphere can live through your posts till summer gets here.

 

[Diamondback]

i finally had a chance to test the new battery. i have to say is WOW what a difference decent power makes !

my top speed (unassisted) has increased to 41kph on flat ground at 31A.
even at 31A load, the pack never went below 24.1V. also, the increased voltage at load, seems to have helped
with my current draw issues. max current drawn was 36.5A. with the previous Ni-Mh pack, it would have been up near 44A!

it was only a short fast ride, just to test the pack. i did 6km in 13 minutes. with some hills and head wind.
took 6ah from the battery for the trip, or 15wh/km. (i was not interested in economy, just a power test)

i am more than happy with the performance of the pack. it was barely warm at the end.
the BMS was a little warmer, but still not what i would call hot.

today has been the first day that was cool enough to ride. most days this week have been over 38c......
today it was a more respectable 25c....

i hope to ride to work a few days this week (weather permitting) that's a 34km round trip.
once that's done, i can report on the range of the pack, though i suspect that with my riding style,
it will be about 25-28km per full charge.

here are some pics of the finished battery box and battery.





















Jason.

 

[Diamondback]

Final update....... i rode to work and back today (36km round trip)

this pack is simply amazing. it suffers almost zero voltage sag, gives the motor way more torque,
and my unassisted top speed has increased to 42kp/h. even at 35A draw, im still seeing 23.5V at the CA screen !

this (i think) has helped with my excessive current draw too. with the Ni-Mh pack sagging as low as 16.8V, i was seeing up
to 46A max. now with the new LiFe pack, i have not seen more than 36A max.

also, after my commute of 18km (each way) the Ni-Mh pack was too hot to hold comfortably. the new LiFe pack is not even slightly warm.

from the figures i got today, the range to 80% DOD should be about 34km on a charge.
that's mainly due to the way i ride (fast ) almost constantly at 30A load. and 40km/h.
im sure i could get more than 50km out of it if i went a little slower, but where's the fun in that ? :wink:

with the 8A charger, i was able to fully recharge after getting to work in just over 1hr 15 mins. (8.733A drawn) for 17.95km.
took 11A for the trip home (the trip home is more uphill) and recharged in just 1hr 40 mins.
compared to the old Ni-Mh and 4a charger which took hours and hours to recharge (often more than 6hrs), im very happy.

im now loving the ebike thing even more that ever.

apart from the hot weather..... last few days have been in the high 30's and tomorrow is predicted to hit 41 (c).
far too hot to ride to work im afraid.......

Jason.

 

[Ypedal]

Cool !!! told you these cells rock !!! :wink:

40celcius ?.. daaaamn.. supposed to be - 35 c tonight in Canadian land Maritimes.. !!!

Best to run high rpm's over low rpms at the motor if you want to draw less amps... if you bog the cyclone down it will suck power and get really hot.. watch the motor temps with this new pack !!

 

[Diamondback]

yes, the cyclone loves to eat amps..... but with the new pack the motor is actually drawing LESS than it was before.
i think it's due to the lower voltage sag. more volts, means less amps (right ?)

anyway, i am very impressed with this pack. if it gives me the cycle count that it's supposed to,
i will be more than happy. still cant believe that the pack did not even get warm under the 30A load !

the Ni-Mh pack was too hot to touch, and the LiFe pack not remotely warm. the wires to the motor were warmer than the pack !
and even the BMS was only a little warm....

the cyclone motor on my bike has always been hot at the end of a trip.
i think it's a fact of life for the cyclones......

Jason.

 

[Ypedal]

These cells will gladly power 2 cyclones, with 20ah ( 2 cells in paralell ) you are good for up to 200 amps + ! ( The BMS won't let you do that however )

 

[Diamondback]

yeah, the BMS is rated at 75A on my pack, but that's more than enough for my needs anyway.
this pack will most likely run my next ebike too.....

(yes, ive been bitten, and now want to build a better one next time......)
im keeping a close watch on a number of very interesting threads round here at the moment.
what with Matt's RC drive, and David's motor, things are looking very promising indeed.....

Jason.