48v 15ah 80 cell vs 48v 15ah 16 cell LiFePo4

E

EbikeWizard

10 W
Joined
Oct 7, 2012
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I have a 48v 15ah lifepo4 battery from a cheap ass ebay vendor from china that is made up of 80 cells
each cell is 3.2v and 3.2ah
3.2v times 16s equals 51.2v
3.2ah times 5p equals 16ah
51.2v times 16ah equals 819.2watts

i am getting a new Do-It-Yourself 48v 15ah lifepo4 battery kit from headway headquarters that is made up of 16 cells
each cell is 3.2v and 15ah
3.2v times 16s equals 51.2v
51.2v times 15ah equals 768watts

which is the better battery?
which will last longer?
which will be more powerful?
which one will be more durable?
 
With 80 cheap cells in your eBay pack, you'll definitely have problems. Trying to fix that pack will also be challenging.

The Headway cells are much higher quality and will be much easier to troubleshoot if needed.
 
EbikeWizard said:
I have a 48v 15ah lifepo4 battery from a cheap ass ebay vendor from china that is made up of 80 cells
each cell is 3.2v and 3.2ah
3.2v times 16s equals 51.2v
3.2ah times 5p equals 16ah
51.2v times 16ah equals 819.2watts

i am getting a new Do-It-Yourself 48v 15ah lifepo4 battery kit from headway headquarters that is made up of 16 cells
each cell is 3.2v and 15ah
3.2v times 16s equals 51.2v
51.2v times 15ah equals 768watts

which is the better battery?
which will last longer?
which will be more powerful?
which one will be more durable?
Click to expand...

which is the better battery? Relative
which will last longer? If both are lifepo4, they may have very similar lifespan.
which will be more powerful? What? The cheap ebay one, no question. 819 to 768.
which one will be more durable? Relative

If it ain't broke, don't fix it.
 
bowlofsalad said:
EbikeWizard said:
51.2v times 16ah equals 819.2watts

51.2v times 15ah equals 768watts
Click to expand...

which will be more powerful? What? The cheap ebay one, no question. 819 to 768.
Click to expand...
Actually, that's not the measure of power, only of capacity. EbikeWizard left off a very important unit, "hours". Both of those are Watt-hours (capacity), not Watts (power).

One would need to know what the current limit of the BMS on each pack is, to find out what the max power it could theoretically output might be, and to find out what it would actually be one would also need to know the voltage curve of the cells in question, to determine how much sag they would have at that current draw and state of charge, to see what hte actual wattage output should be.
 
999zip999 said:
Do you have a link so we can compare ?
Click to expand...

new http://stores.headway-headquarters.com/-strse-103/DIY-48v-lifepo4-battery/Detail.bok?category=DIY+BATTERY+KITS

old http://www.ebay.com/itm/48V-15AH-LiFePO4-Li-ion-Battery-Electric-Scooter-/290444223122?pt=LH_DefaultDomain_0&hash=item439fd32292

and by the way the old cheaper 80 cell lifepo4 battery had 8 damaged cells when i got it, i bought replacements and soldered them in the pack myself and the bike still runs reliably to this day http://endless-sphere.com/forums/viewtopic.php?f=14&t=44478
 
Theoretically, the headway cells have a better C rate, so therefore more able to put out amps. Amp hours will depend some on how close to the max c rate you are discharging.

So it's entirely possible that the real world, on your bike, capcity of the headways will be equal to or even better than the low c rate cheap stuff.
 
amberwolf said:
bowlofsalad said:
EbikeWizard said:
51.2v times 16ah equals 819.2watts

51.2v times 15ah equals 768watts
Click to expand...

which will be more powerful? What? The cheap ebay one, no question. 819 to 768.
Click to expand...
Actually, that's not the measure of power, only of capacity. EbikeWizard left off a very important unit, "hours". Both of those are Watt-hours (capacity), not Watts (power).

One would need to know what the current limit of the BMS on each pack is, to find out what the max power it could theoretically output might be, and to find out what it would actually be one would also need to know the voltage curve of the cells in question, to determine how much sag they would have at that current draw and state of charge, to see what hte actual wattage output should be.
Click to expand...

I suppose this comes down to what you value more, range or speed. You can say, that is a really powerful guy, he could either have excellent stamina or strength, but either would be powerful. Personally, I value range :D
 
dogman said:
Theoretically, the headway cells have a better C rate, so therefore more able to put out amps. Amp hours will depend some on how close to the max c rate you are discharging.

So it's entirely possible that the real world, on your bike, capcity of the headways will be equal to or even better than the low c rate cheap stuff.
Click to expand...
thank you dogman
you made the high price i payed for this battery seem very worthwhile
i just cant wait to get these batteries

i have to design a battery case to fit on my bike, i will need the exact dimensions of the batteries and the 2 hole spacers
i want to have my battery case designed before the batteries even get here
i im using a cad program called FeatureCAM, and i will be using a CNC machine to make the parts
can anybody get me the blueprints of the spacers at least?
i think i already have an accurate blueprint of the batteries
but if anybody has a better blueprint i would like to see it
 
i have got the blueprint,
i spoke to the good folks at headway headquarters
and they immediatly sent me the blueprint i needed
40152 Spacer Block Drawing.jpg
now i can begin to design my case
before my battery even gets here
when it does get here im just gonna pop all my batteries into place and go.
ill put up a video on youtube, ill get somebody to film me using my other ebike
 
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