36V 9Ah Li-ion batteries in plastic cases ARE HERE

[xyster]

These cells obviously cannot work great as you must build so huge ( 300 cells ) pack for the sake of theirs inefficiency.
Once again you failed - or maybe i'm wrong again ?
Maybe "work great" mean for you a lot of money throw out for huge and heavy battery pack - which will be unable to work soon for the sake of rising internal impendace and low number cycles that still left.

Look at those specs again. The cells are 46 grams each. 300 are 13.8kg (30 lbs). That's lighter than many if not most battery packs here of far less capacity.
I got the cells for $3 each. $900 for a 33ah, 2.5 kw-hr pack is comparatively cheap. I would've bought emoli's but I wanted at least 2 kw-hr of energy, which would require 180 emoli's at bare minimum $10/cell -- $1800 is twice the price of my pack and I couldn't afford that.
These 18650s put out just over 1C reliably for 9 months with no evidence of significant degradation. No I don't think they're 1.5C cells, I think they're 1C cells. I regularly pull 30-35 amps from the pack for extended periods.
Other people here have had success with these same cells including Patrick Mahoney, who uses a much smaller 12s8p pack with a 20 amp controller, and Aerowhatt from the old forum, who ran them on his scooter in parallel with his SLAs.

Where's your ride, dude? I don't even know what you have...

 

[markcycle]

I'm trying to decide if this battery is right for me. I plan on wiring two packs in parallel

I found this data sheet on the battery which states on the plots its a 2c battery

http://www.crystalyte.com/lithium%20battery%2036V%2010ah.htm

Any opinions I'm running a WE brushed hub. speed isn't the issue for me its range. How much better range will I get over the stock lead acid, which seem to be down to 31 volts or so at 7AH according to my Watts Up meter after 12 miles.
Mark.

 

[Ypedal]

Depending on how long ago you got the WE kit, it very well may have a 35 amp controller.. 2 of these packs in paralell would be 20ah, needs testing .

 

[markcycle]

Depending on how long ago you got the WE kit, it very well may have a 35 amp controller.. 2 of these packs in paralell would be 20ah, needs testing .

It does have a 35 amp controller, so 2 in parallel should just about be OK 1.5C, I'm guessing. I'm thinking of lowering the controllers amps (Change or modify the shunt). I never pull the full amps when running even up hills I don't pull more than 20 amps and on the flats about 12 amps. I always get it moving with the peddles before applying full throttle.

I'm gong to give them a try and see what happens If needed maybe I'll go with 3 in parallel though that would put me over my budget
Mark

 

[giveahoot]

The last thing this forum needs are internecine battles. Then it becomes like every other forum out there. I would love to see more information on these batteries and the details fleshed out though. They seem great for the price, and I applaud such an effort. BTW, how many peak watts can the WE brushed hub handle?

 

[markcycle]

This is the manufacturer's spec sheet for the cells in the pack. Are we talking the same batteries because they clearly show the 2C discharge rate

 

[Ypedal]

Hey Marty.

Anything to report so far on these ? have you tried them ?

 

[markcycle]

I got the batteries today from Marty, as promised.

I charged up the frame mount unit for 2.5 hours 41.3 volts 41.9 is fully charged or is the full voltage out of the charger when the batteries are fully charged.

I set the current limit of my controller to 24 amps yesterday

Ride test all results are done using a Watts Up meter

first the batteries will sustain 24 amps the voltage drops to 34 volts

Did a 6.46 mile run no pedaling
21 minutes
4.32Ah total
820 watts peak (Low for you guys)
average speed 18mph lots of stop and go

Batteries seemed to still be going strong

need to do a lot more testing to understand the range these batteries are going to give me

I don't expect more that 10 miles from 1 pack of unassisted riding with full throttle but this has yet to be proven.

 

[marty]

Hey Marty.
Anything to report so far on these ? have you tried them ?

Nope.... Still got one of each. The ones I took apart for pictures. Just sitting on the floor. Been busy working on much bigger electrical projects. Residential house wiring. Happy to say - passed the electrical inspection and service wire was hooked to pole today. Everything works

See that Markcycle is my battery tester. Look forward to hearing more results.

 

[xyster]

first the batteries will sustain 24 amps the voltage drops to 34 volts

Watch for more voltage sag as the lithium cobalt cells age.

http://www.batteryuniversity.com/parttwo-31.htm
" Lithium-ion has a slightly higher internal resistance than nickel-based batteries. The cobalt system tends to increase the internal resistance as part of aging whereas the manganese (spinel) maintains the resistance throughout its life but loses capacity through chemical reaction. Cobalt and manganese are used for the positive electrodes.

High internal resistance will eventually render the battery useless. The energy may still be present but can no longer be delivered. This condition is permanent and cannot be reversed with cycling. Cool storage at a partial state-of-charged (40%) retards the aging process. "

 

[markcycle]

The question is when and how fast the batteries will deteriorate, all batteries have a service life.

If its 500 real cycles to 80% then I'm happy

 

[Mathurin]

I'll point out that Velectris recommends using a timer with lithium batteries to extend their life, the idea being to keep your batteries at a partial discharge overnight, and have them charge a few hours before your morning commute.

 

[marty]

Information from manufacturer. Max discharge current = 15 Amps

 

[markcycle]

Wired two batteries in parallel tonight.
Took the batteries out of there cases and fitted them is a Wilderness battery bag
Those plastic cases wasted space and added weight for no reason. Not to mention they were ugly and cluttered up the bike
End result total weight 10 Lbs for a 37 volt 18Ah battery, Not bad
Garage test using front brake as load fully charged battery at 25 amps voltage was 38 volts
Testing begins tomorrow
see pictures

 

[Lowell]

66.6 Wh/lb, your bike is going to go like the devil! :lol:

 

[markcycle]

Did my first ride with the battery
To review
2 37 volts LI-ION cobalt 9Ah batteries wiried in parallel
30 miles
used 13.1 Ah
at the end of the ride 35 volts @ 20amps
0 amps 37.5 volts

I'm very happy with the battery "THANKS MARTY"

Mark

 

[Johnbear]

How much are you selling these for?

 

[marty]

Not selling anything now. Really don't have time. Wondering why no one seems to be selling these batteries? They are small. One or two packs might fit in one of those little bags that hangs under the seat?

Ypedal why are you not selling these batteries? These 36V 9Ah Li-ion batteries are not some custom made experiment. Think Kenny has them in stock, ready to ship?

Did a Google search. Know nothing about Itselectric.ca? Picture looks like batteries I had?
http://www.itselectric.ca/Products.html

 

[Ypedal]

Ypedal why are you not selling these batteries? These 36V 9Ah Li-ion batteries are not some custom made experiment. Think Kenny has them in stock, ready to ship?
[/quote]


Good question. And it's a complicated answer.

:wink:

It's just my way of doing things i guess.

For the past 10 years of my life i've been questioned, insulted, tested, cried to, laughed at, ridiculed, thanked, overworked, underpaid, mad, puzzled, ... ... ... ... ... ...

Nothing worse than being put on the spot by a customer when you have no clue what you are talking about. 10 years on the helpdesk.. not a single day goes by i don't go " WFT was that all about ? " .. If there is a way to screw something up in some rediculous way.. someone WILL screw it up !

I just like to learn things in detail and know as much as i can about something before i invest in it.

Started with 1 motor for myself... then another .. then 4 .. then 50 and i like what i'm discovering, but i have alot more to learn.

Same thing with the batteries, i put my money where my " wants " were and i'm testing for myself.

I think it's Fechter who has in his sig " one test is worth a 1000 opinions "

 

[Mark_A_W]

I'll point out that Velectris recommends using a timer with lithium batteries to extend their life, the idea being to keep your batteries at a partial discharge overnight, and have them charge a few hours before your morning commute.

Have you got a link to that on their site?

I've had a browse around but can't find that information.

Seems like a good idea. Also, should I store my Lithium Pack in the fridge?

Seems to me I could either store it in the fridge, or put it on a timer. Both is getting a bit difficult