New Ebike user, with need of battery info and opinions

Diamondback

Diamondback

10 kW
Joined
Dec 15, 2008
Messages
540
Location
Sydney, Australia
Hi all.

Long time lurker, first time posting...

My name is Jason, im 36 years old from Sydney Australia, and have just completed the build
of my diamondback Ebike project.

a few short clips of my bike can be seen here.
http://au.youtube.com/watch?v=7bdqNY0LUfU (part 1) follow the links if you want to see more.

i am running a Cyclone 24V 500W mid drive system.
i also bought a battery and charger from ebike.ca. the 24V 18A Ni-Mh pack that i bought is just not suitable
for my riding style, and i find i need a good quality LiFePo4 pack.

i have been looking at the packs on offer from cyclone-tw.com.
these seem to be good. has anyone here used these packs ?

the one i want is the 24V 20Ah pack. they use cylindrical cells.
cyclone-tw.com claims they are good for up to 75A loads.

since my 500W cyclone motor is drawing up to 45A peaks, i think these will be ok ?
i will be commuting 35km per day and charging while im at work.
so far i have been using about 14Wh/Km or about 12Ah of power for each leg of my commute.
current draw averages at about 30A.

the Ni-Mh pack i currently have is a good pack, it's just not suitable for the motor im running. (or my riding style)
the LiFePo4 pack from cyclone-tw.com is not cheap, but i figure you get what you pay for, and i should have just bought a decent pack up front.

learn from your mistakes i guess.....

can anyone offer advice on these packs ?

especially as im about to lay down nearly $900US inc shipping, i really don't want to make another bad decision.
i have looked at the Ping and Cammy packs, but these seem to be suited to lower C ratings, and i need more than they can offer (i think)

the vendor (Paco) says his packs are good for up to 75A , and that the BMS will hold up to 80A peaks.
both those figures are way more than i will ever see on my bike, but i have seen 45A peaks.

Jason.
 
"i am running a Cyclone 24V 500W mid drive system... so far i have been using about 14Wh/Km or about 12Ah of power for each leg of my commute. current draw averages at about 30A. my 500W cyclone motor is drawing up to 45A peaks.."

Your numbers indicate you are averaging 720 watts? that is a lot average. And doing this with batteries not up to the load?

What other numbers do you have,, maybe some big voltage sags? motor temperature?

With these numbers on a 5oow cyclone, You may be about to run into other issues, IF you get batteries capable of delivering 1000 watts continous and you use them at that level.



d
 
Welcome to ES !! ( more posting less lurking = good !! ) 8)

The batteries that Paco offers on his site are from " PSI " . they will indeed put out 75 amps, same cells as Lifebatt/BMI/Eco-gecko/etc... I have used them a fair bit and i do like them.

How hot does your cyclone get after one of your runs ? :shock:

edit to add: the PSI cells will require carefull assembly, the shape of the round cells makes building a pack tricky, cyclone supplies unpackaged cells and leaves it up to the user to build their own ( both a good, and a potential bad thing !! :wink: )
 
thanks for the info on the batteries.

i asked Paco and he said the battery would be assembled and ready to use ?

as for motor temp, it's hot, but not so that you cant touch it.
i am seeing voltage sag as low as 16.7 volts at 44A.

the voltage sag is the main reason i wanted to upgrade to the LiFePo4 pack.
the current NiMh pack is getting me the range i require, but the V sag is killing the performance (and possibly the controller too?)

Jason.
 
answering a few questions.....

on my commute home from work, i saw peaks of 690 watts.
most of the time it was under 500W

voltage sag was as low as 15.9 volts at 42A. Not Good.

if i can figure out how to use the CA to limit current to 35A, the pack might be
better able to withstand the sags...

the motor was quite hot. i could hold onto it for only about 10 seconds or so.
i would guess high 40's low 50's (deg c) probably too hot.

Jason.
 
Keep the rpm's high.. if you are getting 40+ amps.. shift gears !! :wink: ( Or get a bigger motor ! )

20ah nimh pack should be able to dish out 40 amps without any problem however.. i'm surprised to see that much sag... :?

edit(again) : But then again, 24v = 20 cells / 16v = 0.8v per cell..
 
Diamondback said:
answering a few questions.....


voltage sag was as low as 15.9 volts at 42A. Not Good.



Jason.
Click to expand...


Hi Jason,

not that i know what im talking about because i dont, but whats your low voltage cutoff for a 24v pack?

D
 
as far as I know there is no lvc in the controller and as it's nimh there is no BMS either.

I have been told that under load, it should be considered flat once I see any less than 20v.
Most of the time I'm seeing 23v down to about 21v. Those lows of sag that I'm seeing are
What's being reported by the CA. I have never actually seen the voltage that low on the screen.

I do shift gears (all 9 of them) spend most of my time in 6-9 though. I also peddle almost all the time too.
I can't afford the bigger motors, as this one is already more than twice the legal limit here in OZ.
And it's cost me a small fortune to get it this far.

I think if I alter the riding style a little, the nimh pack might last the year.
Hopefully by that time lithium packs will be cheaper and better tech too.

I really don't want to lay down clost to $1300 au if I don't have to right now.
If I can current limit the motor to 35A things should be much better.

Jason
 
How do you go about charging your pack ?

1v per cell is as low as you want to go. So ( I corrected my bad math above.. sorry bout the booboo ) 20 cells = 20v lvc

Is your Cycle Analyst an " Inline " model or the one with the 6pin connector direct to the controller ? ( I suspect an inline as the cyclone controller is not easy to access ) and the max amps setting on the CA will not do anything to cut back the power if it's an inline model.
 
yep, it's the inline version.

there is a way (according to the manual) to use the stand alone versions to limit current.
i just have to get the info from the crew at ebike.ca.

they have been brilliant so far at answering all my questions. and there have been many of them...

as for charging the pack, i use the dedicated charger that i got from ebike.ca
it's a Nexcell 24V 4A nimh charger with cc/cv and peak detection. it also has an over temp protection on it (55c)

it's funny though. after my work commute, i have used about 10A - 11A from the pack (so it should take about 3 hrs to charge)
but it usually takes more like 6 hrs before it starts to trickle charge. and is usually still trickle charging when i leave work.....

maybe with my higher current draws, im not actually getting the rated 18Ah from the pack, and the 11A is nearly flat ?
the more i think about it, the more i think ill need the lithium pack soon.

i just dont know if i should go with the ping v2 pack (cheaper) or run with the cyclone-tw.com pack. (very expensive)
either way, i need one that can handle 30A constant, and 45A peaks.

Jason.
 
the 18ah nimh should put out 15+ah comfortably..

Are you allowing the pack to cool down completely before you charge it ?

the 16v reading you get on the CA can sometimes be the last value the unit saw when you disconected the battery pack and it powered down, not the number to worry about, it's what you see on the display when running that counts..
 
thanks.

I figured that low voltage and high amp usually occur at the same point ?
I don't think I have ever seen less than 19v on the display while I'm riding.

Even so, the 3 LEDs on the controller throttle goes amber under any real load.
Even red on hills. The green will light up on flat ground however.

The pack is allowed to cool for about 2hrs after I get to work.
If I leave it any longer, it will not finish charging for the trip home.

I leave the battery overnight at home before charging in the morning.
As I only ride every second day.

I think I will buy the LiFePo4 pack from Paco.

Then limit the current to 35A

That's probably the best solution to my problems.

Jason.
 
Diamondback said:
Hi all.

Long time lurker, first time posting...

My name is Jason, im 36 years old from Sydney Australia, and have just completed the build
of my diamondback Ebike project.

a few short clips of my bike can be seen here.
http://au.youtube.com/watch?v=7bdqNY0LUfU (part 1) follow the links if you want to see more.

i am running a Cyclone 24V 500W mid drive system.
i also bought a battery and charger from ebike.ca. the 24V 18A Ni-Mh pack that i bought is just not suitable
for my riding style, and i find i need a good quality LiFePo4 pack.

i have been looking at the packs on offer from cyclone-tw.com.
these seem to be good. has anyone here used these packs ?

the one i want is the 24V 20Ah pack. they use cylindrical cells.
cyclone-tw.com claims they are good for up to 75A loads.

since my 500W cyclone motor is drawing up to 45A peaks, i think these will be ok ?
i will be commuting 35km per day and charging while im at work.
so far i have been using about 14Wh/Km or about 12Ah of power for each leg of my commute.
current draw averages at about 30A.

the Ni-Mh pack i currently have is a good pack, it's just not suitable for the motor im running. (or my riding style)
the LiFePo4 pack from cyclone-tw.com is not cheap, but i figure you get what you pay for, and i should have just bought a decent pack up front.

learn from your mistakes i guess.....

can anyone offer advice on these packs ?

especially as im about to lay down nearly $900US inc shipping, i really don't want to make another bad decision.
i have looked at the Ping and Cammy packs, but these seem to be suited to lower C ratings, and i need more than they can offer (i think)

the vendor (Paco) says his packs are good for up to 75A , and that the BMS will hold up to 80A peaks.
both those figures are way more than i will ever see on my bike, but i have seen 45A peaks.

Jason.
Click to expand...


Jason, the peak current of my batteries(24V) is about 90A. But it can't last for long.
I think the scooter can reach peak current when starting. It needs little time.right?
The discharge rating is 2c-3c... :wink:
 
have you had a look at headway cells/packs?

tell us about the video camera used for your youtube vids. I just watched the three part series you made and clicked on the "view HD" button.

The quality blew me away (for youtube) on my 1280x800p laptop screen.

Cheers!
 
have not looked at those cells....

ended up ordering the cyclone-tw.com pack.
they seem to be made from good high rate cells, and the vendor is willing to replace any bad cells that do turn up,
and offer a 2 year warranty as well.

the warranty is what finally sold me on that pack.

all of my youtube clips were recorded using a Sanyo Xacti Full HD video camera.
it's a great unit, capable of recording in many different resolutions including the following.

320x240 30fps
640x480 30fps
640x480 60fps
1280x720 30fps (the one i use for YT clips)
1280x720 60fps
1920x1080i 60 field/s

records to SDHC cards as mpg4.

not really cheap, but you get what you pay for (as with most things in life i guess)

i will give my thoughts on the cyclone pack once i get it.

Jason.
 
I hope the pack works out! Can you give us a link to the built pack you ordered?
Thanks.
 
good idea.

would not want it shaking itself apart now would we ?
i would not have thought to check that at all.... might have saved me a load of money and time there Ypedal...

question is, how would i support the cells ?
obviously any support medium would need to be hugely fire resistant and heat proof too....

the pack should get here in a few days.
ill post pictures once it arrives.

Jason.
 
here's a link to the cells and BMS info.

http://cyclone-tw.com/lithium.htm

and here's the link to his online store.
the pack that i ordered is the 24V 20Ah LiFePo4, it's pictured 2nd row, in the middle.
well, the bag and charger is pictured..... cant actually see the pack......

http://cyclone-tw.com/order.htm

the vendor (Paco) has been very responsive to all my questions.

Jason.
 
good to know that they cope with the expected 35A - 40A loads so well.
there will be decent fuses on the output leads, so failing an internal short, i think ill be good to go....

should i run a 50A fuse, or a circuit breaker ?
the breaker would obviously be more convenient (if it should even be needed)
but fuses are cheaper......


PS...

Just in case anyone is wondering about the "24V 200W Brushless DC 2500 RPM" sticker on the motor....
in australia (as you may or may not know) the maximum allowed power is 200W.
so i had some stickers made up, that might throw the cops off the scent if they should become interested in me.....

if the cops can prove that the motor is over 200W, you can be fined up to $1500 AU.
$500 for no rego, $500 for no insurance and if you happen to have no license another $500.

Jason.
 
Update......

It's Here !

the battery turned up this morning.
unlike the experience others have had, mine was very well packaged.
there was zero apparent damage either on the box or the contents.

shipping only took about 5 days.

the battery itself looks well assembled (ill post a few pictures later tonight when i get home from work.)
as promised, Paco sent me the 8A charger in place of the regular 5A one.
the pack is charging as i type.

unfortunately, i will have to wait till the weekend before i can try it out, as i have to go buy some Anderson plugs
for the output on the battery.

also, my current bag is not big enough, so ill have to go buy a larger one.....
the battery did come in it's own bag, but my bike has a Topeak MTX slide in rack/bag system.
so i will have to go buy a bigger one for the battery bag......

Jason.
 
it's a 20Ah pack, so the charger should take a little over 2 hrs.

it took only about 20 mins to get from 70% to full today....
voltage was 26.9 straight off the charger. the pack is in what looks like a 8s2p configuration....

pics after i get home tonight at 11pm oz eastern time....
 
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