difference between standard vs max continous discharge vs peak how to establish what is needed for a motor's need

[sharinginfos]

hi
i need clarification
on benergy site i see 3 mesures for discharge . which one do we have to take into consideration? for example if a motor is rated 30amps how to determine the battery amps needed. so far i read that it is better to have 10amps more in the battery than the motor is asking to not stress the battery. so do we use the standard or the max discharge spec to establish calculation?

any comments advice welcomed. those cells are light 150g since external in plastic( i say to myself if i compress them no need to have aluminium casing maybe im wrong...).

but the spec have a big difference 1.4 vs 50amps. why?

Plus if you open the report testing they send me they dont show the same spec as seen on their site or below. this also i would like to understand if someone knows

is benergy recongnised as reliable?

https://www.benergytech.com/Lifepo4-Battery-3-2V-7AH-Prismatic-Cell-pd44615319.html


thanks
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3.2V 7AH Lifepo4 cell. Screw terminal design. Easy for pack composing.Can made different packs in series or in parallel.



Model No.: BPS-LFP7AHP



Parameter Table:

Product Type	Lithium Iron Phosphate Cell
Shell Type	Plastic Shell
Brand Name	Benergy
Voltage	3.2V
Nominal Capacity	7AH
Minium Capacity	7AH
IR	≤2mΩ
Size	18*65*100mm (W,L,H)
Weight	150g±10g
Charge Mode	CC/CV (Continuous current/Continuous Voltage)
Max Charge Current	7A (1C)
Charge Cut Off Voltage	3.65V±0.05
Standard Discharge Current	1.4A (0.2C)
Max Continuous Discharge Current	50A (7C)
Peak Discharge Current @3 sec	410A (58C)
Discharge Cut Off Voltage	2.5V
Terminals	M6
Cycle Life	>2500 Times (0.5C charge/discharge, 100% DOD)
Discharge Temperature	-10～55℃
Charge Temperature	0～45℃
Application	Electric boat, yacht, marine, EV etc.
Warranty	2 Years
OEM/ODM	Yes(Accepted)

 

[neptronix]

Boy, that's quite a spread between continuous max and standard.
What would help you determine what the real power is, is a discharge graph of the cell at various C rates so you can find the nominal voltage at various C rates, then find out where the sweet spot for power vs range is.

My educated guess is that they'd be best at 1-2C continuous.


One red flag about this company is that their specs aren't lining upon their batteries. They say it's for a 1500w motor but the maximum continuous discharge current for this battery is 720w ( 15 x 48 ).

Another thing is, 5kg or 11lbs for a battery of this size, using lifepo4, is not realistic. That's the weight for a battery with ~200whrs/kg; i don't know of any lifepo4 formulations with that level of energy density.

From this listing: https://www.benergytech.com/Lifepo4...e-Electric-Motorcycle-Battery-pd47489339.html



When you see a company playing so loose with numbers like this, and without detailed spec sheets for their cells, it's a good idea to tread with caution!