A123 AMP20 LiFePO4 Power Battery cell 20AH

[Alastor]

Hey everyone ,

I was considering taking 200 of this lifepo4 cells in order to put em out in the European market since there are no good cells selling here and there is a big need.
There specs are High power with over 2,400 W/kg and 4,500 W/L and the total cost per cell to my door from out of china is 31 dollars.
Is that a good dead what do you mates think ?

Thanks in advance

 

[Hugues]

hi,

i could be interested in 20AH

could you post the exact dimensions of a pack and detailed specs ?

thanks

Hugues
Switzerland

 

[Alastor]

Here are the specs mate

A123 3.3Ah 20ah cells
A123 AMP20 LiFePO4 Power Battery cell 20AH
Capacity:20AH
Volatge:3.2V
High usable energy over a wide state of charge (SOC) range
and very low cost per Watt-hour
Excellent abuse tolerance and superior calendar and cycle life from
A123’s patented Nanophosphate® lithium ion chemistry
High power with over 2,400 W/kg and 4,500 W/L
AMP20 Cell Specications
Cell Dimensions (mm) 7.25 x 160 x 227
Cell Weight (g) 496
Cell Capacity (minimum, Ah) 19.6
Energy Content (nominal, Wh) 65
Discharge Power (nominal, W) 1200
Voltage (nominal, V) 3.3
2400
131
Energy Density (nominal, Wh/L) 247
Operating Temperature -30°C to 55°C
Storage Temperature -40°C to 60°C
Test Result
Nail Penetration Pass – EUCAR 3
Overcharge Pass – EUCAR 3
Over-discharge Pass – EUCAR 3
Thermal Stability Pass – EUCAR 4
External Short Pass – EUCAR 3
Crush Pass – EUCAR 3
APPLICATIONS
Utility-scale Storage

 

[ranriegler]

sorry mate youv got it all wrong accept the weight
these batteries are all b grade of batteries that in the beginning weren't so good
i got information from mavizen them selves that are the official and only dealer that these cells are nothing close to 30c discharge even in the a grade class.
i wouldn't pass them more than 3c and also then there will be quite a high sag in volts. the cells are of b grades of a few factories so there are cells less tolerant to low voltage. some cells are soft some are hard some are printed good some aren't ,some are printed made in korea some made in usa ofcorce all are made in china. there are afew that will stand low voltage like being taken down to 0 volts and wont be damaged if it happens once for a few minutes but most of them will be loosed. today most of the cells have shortened tabs with holes in them that are made for welding , not so good cause you need to get special solder to weld the aluminium positive tab that i don't know were to get . in general i dident say these cells are not good . they sell 30 pcs for 450$ by victpower that's 15$ each for 500 grams . cheaper than pizza. but don't forget the DHL shipping that will be 45$+7$ for every 500 grams . add to it vat and tax and you will easily get to 30$ a peace
and also don't forget these cells need agood bms board to manage them, you can use smartec bms for 25$ at atomic battery or 30$ at atatech that wont balance perfectly because you will need your controler to cut of the volts in the right low cut of volt and if the cells wont be balanced good one of them will pass the safe volt and will be cut off at 2.0v insted of 2.5-2.6v. with anew battery it will be ok with an old battery i dont know . i think to try the capacitor bms of freego , its suppose to balance much better because it works in anew way instead of trimming the extra volts of the cells it switches capacitors so distributing power from full cells to low voltage cells , and its very cheep only about 23$ for 30-60amp 6s (my use) but i don't know it sounds to good to be true i wonder were is the catch in this capacitor bms ????

 

[agniusm]

sorry mate youv got it all wrong accept the weight
these batteries are all b grade of batteries that in the beginning weren't so good
i got information from mavizen them selves that are the official and only dealer that these cells are nothing close to 30c discharge even in the a grade class.
i wouldn't pass them more than 3c and also then there will be quite a high sag in volts. the cells are of b grades of a few factories so there are cells less tolerant to low voltage. some cells are soft some are hard some are printed good some aren't ,some are printed made in korea some made in usa ofcorce all are made in china. there are afew that will stand low voltage like being taken down to 0 volts and wont be damaged if it happens once for a few minutes but most of them will be loosed. today most of the cells have shortened tabs with holes in them that are made for welding , not so good cause you need to get special solder to weld the aluminium positive tab that i don't know were to get . in general i dident say these cells are not good . they sell 30 pcs for 450$ by victpower that's 15$ each for 500 grams . cheaper than pizza. but don't forget the DHL shipping that will be 45$+7$ for every 500 grams . add to it vat and tax and you will easily get to 30$ a peace
and also don't forget these cells need agood bms board to manage them, you can use smartec bms for 25$ at atomic battery or 30$ at atatech that wont balance perfectly because you will need your controler to cut of the volts in the right low cut of volt and if the cells wont be balanced good one of them will pass the safe volt and will be cut off at 2.0v insted of 2.5-2.6v. with anew battery it will be ok with an old battery i dont know . i think to try the capacitor bms of freego , its suppose to balance much better because it works in anew way instead of trimming the extra volts of the cells it switches capacitors so distributing power from full cells to low voltage cells , and its very cheep only about 23$ for 30-60amp 6s (my use) but i don't know it sounds to good to be true i wonder were is the catch in this capacitor bms ????

I think you got it all wrong. Most of the info Alastor copied from whatever Chinese site is correct with few typos.
I would not go with such bold statement when you have not tested them yourself. Mavizen is talking sh*t. It was proven many times on this forum that these cells most of the time meet their description. Any lithium cell that was discharged to 0V is damaged in some way or another and this is probably true for any battery chemistry.
These cells are 10C constant with cooling 30C burst discharge. I am pulling 500A short time current on my car battery made out of 4 of these cells. I have done few minutes discharge test at ~210A. All of lithium chemistry cells need management system. I would suggest read and research first and than post as there is lots of info about these cells even in this battery technology topic.

For Alastor. If you can get those cells and they will be full tabs, made in USA marked cells, 31USD per cell is good price for delivered cell if TAX and duty is included in the price.

 

[davec]

mavizen is too expensive @ 55/cell that's why we stick to back door cells of unknown quality with mis-aligned tabs etc order extras and take our chances.....a 1c cba test from mavi clearly shows a difference - it's all a matter of luck- some were able to buy a batch that came pretty close to the real cells from mavi but others got poor cells like this fellow http://endless-sphere.com/forums/viewtopic.php?f=14&t=46714