recycled laptop cell ebicycle battery pack builders club

This is why im thinking laptop cells are probs not the best choice for my project - the controller requires a min of 55v and a max of 80v all at 40amp nominal discharge rate and the rear hub motor is a 2880w phoenix 2 brushless hub, wich electric rider that i got it from advised 45mph-52mph max speed and 30mph cruising speed would be fairley easy to achieve.

I have built the MTB based around the Specialized Demo 8 team frame with 8" of travel front and rear; Big Upside down motorcross style forks. iv chosen this type of bike so that it will take the punishment the high speeds will give it and im expecting it to be very heavy once all the batteries are on it (approx 60-70kg) but i dont beleive after reading on here that laptop batteries are the way forward for this but i dont want to use LiPo either due to the dangers of messing about with them as i think they are a very volatile tech.

I think im going to have to bite the bullet, sell some stuff and go for the expensive option - was thinking maybe Panasonic LiNiCoAlO2 18650 batteries (arround £7-£10 each) as these will give a constant discharge of 10C allowing a much smaller pack to be built saving a little weight off the final bike.

as for range - i would be happy with 15 mile to be fair......
 

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This said - i currently have over 100 18650 cells that all seem to be charging fine but no other testing has been done on them; and are all of mixed manufactures and another 20 or so laptop batteries that are waiting to be stripped.

is thier anything i could acheive to get this build moving with what i have - if not is any 1 interested in buying them :D
 
SamTexas said:
T04D said:
- was thinking maybe Panasonic LiNiCoAlO2 18650 batteries (arround £7-£10 each) as these will give a constant discharge of 10C
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Where did you get that 10C figure!!????
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http://www.ebay.co.uk/itm/171010752994?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

thier mate, it looks legit to me but then again im still canny new to all of this :)

they are meant to be the replacement for IMR batteries
 
22.2V - 41.6Ah eZip pack.

Still segregated into 2 - 22.2V 20.8Ah banks ... not done testing yet.
Might "evolve" into 44.4V 20.8Ah pack?

file.php


See - 22.2V Battery Woes!
 
DrkAngel said:
22.2V - 41.6Ah eZip pack.

Still segregated into 2 - 22.2V 20.8Ah banks ... not done testing yet.

mint mate :) wish i had bought matched laptop batteries now - im going to need thousands of cells to get enough that are matched in capacity to get anywhere :cry: just too much work with too many wasted cells

keep up the good wrk :)
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T04D said:
SamTexas said:
T04D said:
- was thinking maybe Panasonic LiNiCoAlO2 18650 batteries (arround £7-£10 each) as these will give a constant discharge of 10C
Click to expand...
Where did you get that 10C figure!!????
Click to expand...


http://www.ebay.co.uk/itm/171010752994?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

thier mate, it looks legit to me but then again im still canny new to all of this :)

they are meant to be the replacement for IMR batteries
Click to expand...

That's 10A not 10C. 10A for a 2.9Ah cell is 3.45C. And until I can verify that the 10A was ACTUALLY published by Panasonic, I would take that figure with a grain of salt.
 
ah right - thats where iv been going wrong - i thought when talking batteries "C" was the same as amps (my inexperience showing nicely.lol)

still though with 10Amp per cell the pack could be alot smaller than using laptop batteries? but your right though - i could stick any batteries on e-bay with any information i liked, dont make it true :D

what`s is the calculation from amps to "C" and that means that the LiPo cells rated @ 30-50C are like ridiculously high amp?

cheers man
 
and if this is the case then i think 5 x 14.8v 6000Mah LiPo packs in series is the way forward for my build - a moment of clarity i think...... :)
 
C decided by battery capacity in amp hours = how much power you can draw out at any one time (how many amps)

so with a 10 amp hour battery (10Ah)


0.5C= 5amps

1c = 10amps

5c = 50 amps



amp hours = how many amps you can pull out of a battery for an hour before it's flat

so 10ah = 10 amps for an hour, 5 amps for 2 hours or 20amps for 30min


(amp hour rate is not quite perfect... the slower you draw it out the better... once you get up over the battery C rate it's less efficient and you start to loose power as heat)
 
Brilliant - thank you :)

and sorry for drawing the thread away from its intended purpose
 
no problem

and it's a thread about batteries, so it's all good, we were all asking the same questions as you at one time :)
 
http://www.ebay.co.uk/itm/220873511070?ru=http%3A%2F%2Fwww.ebay.co.uk%2Fsch%2Fi.html%3F_from%3DR40%26_sacat%3D0%26_nkw%3D220873511070%26_rdc%3D1

this any good ? and worth getting to test my used laptop cells with ? will it tell me much ?
 
T04D said:
and if this is the case then i think 5 x 14.8v 6000Mah LiPo packs
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LiPo as in HobbyKing RC LiCo? Those that have wishful astronomically high C rates? I would definitely recommend those to you if you were my archenemy. Since you are not, no recommendation from me.

If you are serious (forgive me, but I seriously don't think you know what you want at this time) about riding a bicycle at suicidal speed for 10 to 20 minutes before running out of juice, then your only SAFE option is A123. That's my UNsolicited advice.
 
SamTexas said:
T04D said:
and if this is the case then i think 5 x 14.8v 6000Mah LiPo packs
Click to expand...
LiPo as in HobbyKing RC LiCo? Those that have wishful astronomically high C rates? I would definitely recommend those to you if you were my archenemy. Since you are not, no recommendation from me.

If you are serious (forgive me, but I seriously don't think you know what you want at this time) about riding a bicycle at suicidal speed for 10 to 20 minutes before running out of juice, then your only SAFE option is A123. That's my UNsolicited advice.
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I was looking at the turnigy nano tech packs - but your right. iv built the bike and have no power source and no idea as to what to get mate - i know i want to go fast and i know i dont need to do very long rides (10- 15 mile would be more than enough) but im just learning in regards to battery tech and any and all advice is welcome :)
 
I started with the laptop batteries as i thought it would be a cheep way of getting the thing moving but now i realize for the power i require it is impractical to continue on this path and to get the bike to do what i want it to im going to have to spend quiet a large amount of money - this is why im bouncing from idea to idea as i dont want to spend any money on something thats not going to fulfill my expectations :D

this is why i joined this site - i new thier was endless amounts of experience builders that i could gain knowledge from and hopefully avoid any mistakes and avoid wasting money :p
 
As I said, if fast and short is what you want, then the only safe choice is A123. Or the only one I can recommend with a straight face.
 
SamTexas said:
As I said, if fast and short is what you want, then the only safe choice is A123. Or the only one I can recommend with a straight face.
Click to expand...

cheers man - and by A123 this would be lifePo4, as this is the pack electric rider where supplying with thier kits if they were willing to ship to the UK :)
 
or headway cells

check out http://www.bmsbattery.com

expensive, but you get what you pay for

if you want fast acceleration and high top speed, then you need a decent battery pack


(I'm building laptop cell packs as range extender packs)
 
T04D said:
I started with the laptop batteries as i thought it would be a cheep way of getting the thing moving but now i realize for the power i require it is impractical to continue on this path and to get the bike to do what i want it to im going to have to spend quiet a large amount of money - this is why im bouncing from idea to idea as i dont want to spend any money on something thats not going to fulfill my expectations :D

this is why i joined this site - i new thier was endless amounts of experience builders that i could gain knowledge from and hopefully avoid any mistakes and avoid wasting money :p
Click to expand...
Run the A123 or other high C pack. We will see you later working on laptop batteries when you get tired of the super fast acceleration and need range at a common speed. :)
 
knighty said:
http://www.ebay.co.uk/itm/220873511070?ru=http%3A%2F%2Fwww.ebay.co.uk%2Fsch%2Fi.html%3F_from%3DR40%26_sacat%3D0%26_nkw%3D220873511070%26_rdc%3D1

this any good ? and worth getting to test my used laptop cells with ? will it tell me much ?
Click to expand...

bumping this... still looking for feedback... cheap enough to by one to try out, but not sure how much the readings it gives will help ?
 
IR (Internal Resistance) is a haphazard method of determining battery condition-capacity.
Ah meter recommended ... several listed - eBike Toolbox or iMax B6, same thread.
 
to capacity test, I was thinking of using 10 x 4s cell holders, to make a 40s1p rig, connect up to a 240v light bulb for discharge, discharge for set amount of time (don't know how long yet)

then check the individual cell voltages, and toss the low voltage cells


with enough cells, cheap enough, I can toss any which are slightly suspect :)



I've already got 10 x 4p cell holders for charging the cells up first, right now I'm bodging them into my 2am 6cell charger, but I've got a 30amp psu on the way to use instead... the cheap 6cell charger I got on ebay isn't very reliable... fully charged cell voltages vary from 4v to 4.2v
 
DrkAngel said:
IR (Internal Resistance) is a haphazard method of determining battery condition-capacity.
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Have you ever had a good battery that had high IR or don't you ever measure it? Is it fair to say you do a charge and then a self discharge first. Then you do a discharge using a fixed resistance to figure AH and discharge time? I assume you disregard the hot resistance in calculating AH. Did you ever have a battery with bad leak down voltage have good capacity?

Thanks
Steve
 
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