ebay LiFePO4

[Lenk42602]

Hey all,

what are the pros and cons of this pack?yesa?sam? anyone familiar with the company?

http://cgi.ebay.com/LiFePO4-electric-bike-Scooter-48V-12Ah-battery-pack_W0QQitemZ270177623426QQcmdZViewItemQQssPageNameZRSS:B:SRCH:US:101

 

[markcycle]

definitely interesting certainly the options are growing. I believe someone on this forum had the 24 volt pack from them. The batteries are from Yesa

http://www.yesa.com.cn/ehibition/ehibition_default.asp?id=2488

 

[BiGH]

my 36v x 2 pack should arrive today

can't wait to get home lol

 

[Freddyflatfoot]

And i should get my 24 volt/10 AHr pack this week. Can't wait!

 

[cerewa]

My 24V 10Ah pack from yesa (missbattery on ebay) came to my doorstep when I wasn't home, yesterday.

They will re-deliver it on monday when my girlfriend is home. Yay!

Unfortunately, I don't have a motor to use with it yet. Hopefully that will arrive in a week.

 

[Freddyflatfoot]

Ok, the jury is still out on how good this battery is, but now my bike feels like a normal bike again!
I can lift up the back wheel without doing a pooper valve!
So far, so good, just need to do a distance trial and see what the range is like, and usable AHr's.
Cheers!

 

[TylerDurden]

I can lift up the back wheel without doing a pooper valve!

Shit, that's funny!! :lol: :lol: :lol: :lol: :lol:

 

[Lenk42602]

fellas - I am in contact with sam from yesa regarding a 48v 20 AH pack for my Version 2.0. I am prepared to purchase but would still like to hear more input from what you think of the packs. Let me know your thoughts as they develop......

len

 

[recumbent]

We certainly are on the beta testing area of these batteries.

Aren't they similar to a123 cells? Only more developed. :? I'm wishing.

 

[magudaman]

For the price You could almost go a123 and the C rates seem very low so I'm staying away.

 

[BiGH]

there is no mention of C discharge rates anywhere for these cells.

My iss ue is more that there are no good bms boards for with built in balancing for A123 cells.

These cells are definately still being tested, however now lifebatt isn't availalble, these cells should stay ballanced longer than a123.

 

[Freddyflatfoot]

I think I have seen a discharge rate of 1C, with a burst rate of up to 5C.
I'll try and fine the link again and post it, but that was direct from the Yesa website.

 

[Lenk42602]

still a bit leary about these packs - seems like I can get more bang for my buck (and support) from itselectric.ca with their Li(Ni-Mn-Co)02 offerings.

at least we are all on the same continent.....

 

[Freddyflatfoot]

Ok,
I emailed Sam about the C rates and battery sag at loads,
here is his reply,

Dear Rob,

Thanks for your reply !

The 10AH pack for your 250W motor is enough.

The standard discharge rate is 1C = 10A

You test 22.5V at 15A is normal.

But we do not suggest to have too high rate discharge , since that may reduce the lifecycles.

We can make 12V pack, but 12V pack is not so popular , we have 24V, 36V, 48V pack .

The capacity can be 10AH , 12AH, 20AH .

 

[BiGH]

for comparison i'd like to hear from dewalt owners what the voltage drop at 15a is...

 

[calinb]

This is my first post but I did some reading here before I ordered a 48V x 20Ah pack and two chargers from Sam. Sam encouraged me to wait an extra 10 days to get the "new" cells so I'm probably going to be even more leading (bleeding?) edge. It should be about three weeks before they arrive to power my Phoenix Cruiser rear wheel. I'll keep in touch.

-Cal

 

[fechter]

Welcome aboard! Let us know how that works out. That should be a good setup. Post pics...

 

[Battboy]

there is no mention of C discharge rates anywhere for these cells.

My iss ue is more that there are no good bms boards for with built in balancing for A123 cells.

These cells are definately still being tested, however now lifebatt isn't availalble, these cells should stay ballanced longer than a123.

CORRECTION:

We up-dated the site with the new Pricing for Individual Cells and Soft Packs with the proper Warranty information, so feel free to go there for any details you need. http://www.lifebatt.com/index.html

On the first page you can click on the Yellow Button for Individual Cell Specifications now.

Thanks for all those who made constructive contributions to getting these cells on the small market. LiFeBATT appreciates your suggestions, and we will always try to accomodate the small buyer as we grow into the future!

Cheers!

Don Harmon

 

[EMF]

for comparison i'd like to hear from dewalt owners what the voltage drop at 15a is...

It's not very scientific, as it's hard to hold a steady amperage while riding...but, I did manage a couple times to hit between 15-16 amps and hold it on a level stretch. It looks like my 60 cell 66 volt pack, drops about 2 volts when well charged. I have a 26 inch bike with a 408 and I weigh about 200lbs. 90.7 kilos

 

[BiGH]

for comparison i'd like to hear from dewalt owners what the voltage drop at 15a is...

It's not very scientific, as it's hard to hold a steady amperage while riding...but, I did manage a couple times to hit between 15-16 amps and hold it on a level stretch. It looks like my 60 cell 66 volt pack, drops about 2 volts when well charged. I have a 26 inch bike with a 408 and I weigh about 200lbs. 90.7 kilos

yes i konw its not, but real world examples are also important. I was just saying that as a response to people above staying how good dewalt was after mirking the ebay cells without looking as a comparison to the voltage drop that Rob was reporting. I said it for some balance! Thanks for the info though that voltage drop is very good, shows the quality of the dewalt cells (in another different style test)

 

[EMF]

Yep, I think real world is important as well, this is why I gave my weight! Hopefully, I will be able to add another 20 cells to my pack soon, as I wondered how this would affect voltage drop and may lower the drop rate when spread over the amp range I use. I often pull upwards of 38 amps, and it drops off more obviously at that current rate, especially near the end of the packs charge cycle. Seems to me, the more cells you have, the less they will drop if they are wired up efficiently.

 

[cerewa]

I just got my ebay-purchased "yesa" 24V 10ah battery pack today. As expected, the BMS is attached to the outside of the battery pack with tape and a piece of shrink wrap that looks like tape. There are of course a bunch of wires coming out of the pack and going in multiple directions.

The charger plug is connected directly to the pack by one wire, and its other wire connects to the BMS

The wires which I assume to be the discharge wires don't have a plug on them; one is connected to the BMS and the other to the pack directly.

The shrink wrap and tape holding the 8 cells together looks strong and durable. Since the BMS circuitboard and ~14 different wires are exposed, the battery pack has an "unfinished product" sort of look. I intend to put together a padded pack that will protect it while it's carried on my bike, while hopefully not insulating it enough to cause overheating. I also want to make a padded case to carry the charger in.

When I bought the pack, I didn't realize that yesa considers its discharge rate to be 1C = 240 watts. Kind of defeats my purpose in buying a 500W motor (my intention is to try to treat the battery very nicely so that it lasts a good long while, but we'll see how that works out in practice.)

On the other hand, if in the future I buy a higher-discharge-rate battery I'll already have a motor that can handle it.

I am also realizing that 240 watt-hours (in rated Ah*rated V) might be pretty low battery capacity for my intended purpose - an 18 mile one-way trip between recharges. I do intend to pedal pretty hard the whole way, though. Still, I might find myself discharging the battery past 70% discharge.

I won't be able to use the battery for another 10 days or so still, because that's the soonest I expect to get the motor and have had a chance to install it.

 

[Freddyflatfoot]

Cerewa,
One I had to do, which was a pain. Was cut the wire for the charge lead, so that it can be mounted from the outside of your chosen container. (I reslodered it and used some shrink wrap tubing on the join)
fo me, that was a small top rack bag, that was just big enough for the battery. Packed the sides with packing foam for added protection.
Good thing is its a nice lightweight pack, and doesn't detract from the 'normal' handling of the bike. With a small hub motor, would make the bike very 'stealth'!