what would a high discharge LIFEpo4 low watthour battery loke like (just to go up hill)

So there are 2 big hill that i have to go up total less than 1km. i can pedal a little bit (both knees hurt) to help my xiongda 48 volt 2speed hub that draws 15 A max. so there need not to be much watthour but rather it would need high continous discharge since i would only put one cell or 2 in parallel. iwant something light. even thought li ion provide good discharge and amp hour per weight i m not willing to gamble with all the hazards and risk. sorry. i look at life po4 wich can emit gaz but rarely ignite.

a battery able to deliver 15 amp is the minimum i want to achieve but if it cost not too much more, i would like better the battery to be able to deliver 30 ampcontinuous since i migth have to end up adding another motor on front wheel if i dont have enough traction in winter needing maybe the front wheel with a q100 similar motor to also provide some effort in case the back wheel sliding on ice snow. Im not there yet, ill try with only one motor but if it does not cost too much more i would rather build a battery that can handle 2 x 15 amps continous or simply a more powerfull motor for futur.


i am willing to solder yes (even more if it not directly on the cells ( like it would be easier to use a setup like the liitokala pict with pre)
iam willing to screw but not to spot weld (unless there is a very easy and cheap way to get a spot welder ... not so encline on the idea though.)

i beleive there are pouch , rectangles and cylindrical lifepo4 available at the moment

A))) ?which good cells provide high discharge that i could use for this setup available genuine sourced?
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LIke how many of these on ebay liitokala would be needed for a 48v battery and would that be a good idea cause some article say they are fake?
B))is it possible to find genuine liitokala ?where. on ebay they are about 8dollar per cell but i dont know if there really have the spec inside the cell. with this setup i would not have to buy a NESE wich ends up cheaper to build i think. or maybe those cells are a not to be found genuine anywhere..
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C))maybe to consider Headway cells would be apropriate ?can we get genuine ones atm?
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D))like how many A123 ANR26650 40 amp continous (are genuine ones still available?) in serie to have 48v? do they also comme with prewelded tabs or i would have to use the NESE module?


feel free to tell me the setups that could answer my 2 hills only problem with my xionda (possible a second hub in front for the future) anything that is light setup(no liion) that can do job that ends up a good bang for buck without me having to spotweld?


thanks

https://www.ebay.com/itm/165479271014?_trkparms=amclksrc%3DITM%26aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D242766%26meid%3Df182d82392ad4ca6a480b901a18e5b24%26pid%3D101195%26rk%3D2%26rkt%3D12%26sd%3D165525584004%26itm%3D165479271014%26pmt%3D1%26noa%3D0%26pg%3D2047675%26algv%3DSimplAMLv11WebTrimmedV3MskuAspectsV202110NoVariantSeedKnnRecallV1%26brand%3DUnbranded&_trksid=p2047675.c101195.m1851&amdata=cksum%3A165479271014f182d82392ad4ca6a480b901a18e5b24%7Cenc%3AAQAHAAABIMFr2e4EmAnM%252ByHZkULYKDIJ4L66fOjNL0iupgt%252BzO1%252F3AE1t3mNirUYB96NktMCicMagiS6mbeTl0xquGODv9l6%252BSPFbGZLpsPgMeSs7T2IJrrRlfRs%252B4ZdwHDlvaAoJvIeL%252F9RHco56pKrfCO366AlTCOyJH6XjASjSehLFB96nbG%252BpYMXpBP9Y2GYDN5pD3v68sdFDlsmVx%252B5dX8hgLsRNTyVcBUFXV2GBfGwrccTMeGK%252BnabkotYpfCJoJ6e%252Bro330JVMnatewnpjvcQKrcE%252FfNSu352z9KDgIE3d0%252FXrNiq%252Fk1mcX3tSKl8xBFaFtybMJrj2ESc2K4YTTKLLuTkFpe1lHjsF8COD1Pvo5P8f%252FtDzMcanxn7C6avYnGLKA%253D%253D%7Campid%3APL_CLK%7Cclp%3A2047675

You would need 16 in serious or 16s common and ez to match

I`m considering 33140 15Ah LiFePo4 cells with support up to 1C (15A) continues discharge (pulse 3C-30s and 5C-10s) in 15s1p (3x5 pack) 48V (for 15x3.2V with 54.75V charger) configuration. One cell weight is around 270g (4kg pack)

Found photos of users soldering those cells:

from:https://electroavtosam.com.ua/forums/viewtopic.php?t=4779

And one on aliexpress:
https://ae01.alicdn.com/kf/A9da8407d384b4f82bdcde7f89ca00275U.jpg

Again 16s is lifepo4 - 48v common. Which would make everything ez. 16s.

Lifepo4 is a good chemistry but big and heavy. How much space do you have ?
Headway screw top cells are easiest. But big.

Found some 26650 30A (10C 3000mAh), weight 85g (so pack 16s1p with bms - around 1,5kg) and there is option for soldering tags (Z form for series)

Some calculations:
Pack will be 48V(51.2V) 3Ah, so around 150Wh and with
lets say 1000W 48V motor(20A) will work around 9 min (150/1000) and with 20km/h speed will cover 3km distance

999zip999 said:

Lifepo4 is a good chemistry but big and heavy. How much space do you have ?
Headway screw top cells are easiest. But big.

Click to expand...

HI zip
i do have some space as i will transport the battery in a regular backpack the weight is more important than the size .

10 years ago there was a bankruptcy sale on
A123 20ah çells . They are 180 amp cells I used them at 80amp max. For 8yrs 1,480 cycles and big and heavy. Love them. Hate big and heavy. Bolt together pack.No bms as 20ah . No bms 20ah and can't. Share. Or try to teach as no bms one man only and may cause fire.Yes lifepo4 can make fire. Late night.Si

v85 said:

Found some 26650 30A (10C 3000mAh), weight 85g (so pack 16s1p with bms - around 1,5kg) and there is option for soldering tags (Z form for series)

Some calculations:
Pack will be 48V(51.2V) 3Ah, so around 150Wh and with
lets say 1000W 48V motor(20A) will work around 9 min (150/1000) and with 20km/h speed will cover 3km distance

Click to expand...

Hi V85 and all

is ENERprof a reliable seller?

Are their ENERpower 26650 LiFePO4 3.2V 3000mAh safe and proof or is this a little know brand that is on the @#problem to be expected @# cheap chinese kind of battery?

I searched and cannot find a picture of U form nor Z form soldering tab. would you have pictures of those to have an idea and why do you propose the Z form over the U form ?

thanks

999zip999 said:

10 years ago there was a bankruptcy sale on
A123 20ah çells . They are 180 amp cells I used them at 80amp max. For 8yrs 1,480 cycles and big and heavy. Love them. Hate big and heavy. Bolt together pack.No bms as 20ah . No bms 20ah and can't. Share. Or try to teach as no bms one man only and may cause fire.Yes lifepo4 can make fire. Late night.Si

Click to expand...

Hi zip
i would like to understand better what you are expressing. You bolted your cells ? Why did you not use bms ?
about the fires I read that yes lifopo4 can catch fire but not propagate to other cell so only one would fire not the neigbourscell. to combust them you need to torch them with an external flame torch. They seem very safe. a link a doc made by fireman similar

it is not to deviate the topic just to share with you :extract from https://www.fire.tc.faa.gov/pdf/TC-16-17.pdf

Figure 17 shows the
results of the Li-ion pouch cell propagation tests. This figure shows the number of cells, out of
the five that were physically connected together, that experienced thermal runaway. All of the
cells, except for the LiFePO4, achieved full propagation to all five cells. Thermal runaway of the
LiFePO4 cell did not propagate to any of the cells beyond the initial one that was in direct contact
with the heater.
the conclusion says also In general, of all of the lithium-ion cells that were tested, LiFePO4 would be considered the
safest cathode material because of the relatively low temperature rise and the resulting low
likelihood for thermal runaway to propagate.

are there other proposition of what lifepo4 cells and setup could be candidate to my need? (enerprof has already named)

Maybe some lifepo4 pouch genuine are available?

sharinginfos said:

I searched and cannot find a picture of U form nor Z form soldering tab. would you have pictures of those to have an idea and why do you propose the Z form over the U form ?

Click to expand...

https://eu.nkon.nl/tags
Also option:
https://eu.nkon.nl/rechargeable/lifepo4/26650.html


On first two questions i cannot give answer

Yeah I used the a123 20 ampere hour pouch cells never buy them if the tabs have been re-welded on they have they'll rip them out of a pack in the rip the tabs too Short then they laser well another tab on there ask them make sure so they ask him a hundred percent is there something that looks like railroad tracks on the bottom next to the actual pouch itself

Look up A123 20ah cell build and info thread and look at druthlede build in page 2.:A bolt together build like mine. I'm at the beach with sunglasses I can't see very well.

I bumped the a123/20 amp hour build thread for you to go through

999zip999 said:

Look up A123 20ah cell build and info thread and look at druthlede build in page 2.:A bolt together build like mine. I'm at the beach with sunglasses I can't see very well.

Click to expand...

Hi from what i see it takes 15 of these to build a 48 v battery right Why did drutledge use 15s 1p and not 16s1p like previously stated above?
i seached for spec, i think each pouch is 496 g so 15x this = 7.44 kg. correct?
for the watt hour that would be 20Amph x 48 v = 960 watthour
for the continous discharge i cant figure out what it is . they use xC or is written z.z do you know it?

Are genuine pouches available from respectable seller? at what price? the ebay guy dont seem to have them in his ebay store.

It seems like a nice build

Hi thanks for showing another options!

Also option:
https://eu.nkon.nl/rechargeable/lifepo4/26650.html
for the Lithium Werks (former A123 systems) ANR26650M1-B 2500mAh - 50A LifePo4 - 3.2V
ill do the calculation with 16 s 1 p since it is what is suggested above

im not certain of my way to calculate that is why i type it in here just to precise.

continous discharge 50 amp
one cell weights 76 gx 16 = 1.216 kg
12 cand $ x 16=192$

I see 8 positive review on their site but what does the community thinks about those cells? and the seller service and trustability?
would you happen to know?

Thanks , i hope you are having a good time at the beach! over here in QC if i go to the beach it would be to do a wim hoff cold water exposure breathing experience hahaha

Interesting A123 in 32157 format with screws on Alibaba OSN Power shop: https://m.alibaba.com/product/751869586/Electric-Bicycle-Cells-A123-32157-With.html

Model NO.: OSN-32157-8AH
Material:Lifepo4
Typical capacity:7-8AH
Nominal Volt:3.3V
N.W:261g
Dimension: (D x H):32mm x 157mm
Maximal Charge Rate:5C (40A)
Continuous Discharge: 30C(240A)
Pulse Discharge: 60C(480A)

Click to expand...

https://m.alibaba.com/product/780238513/LiFePO4-battery-A123-32157-3.3V-8Ah.html

sharinginfos said:

Hi from what i see it takes 15 of these to build a 48 v battery right Why did drutledge use 15s 1p and not 16s1p like previously stated above?

Click to expand...

16s is common (because 12.8V 4s), but with motor there can be 15s for space and weight saving

I'm going to say this to make it easy on you 16s lifepo4 is common as everything made for 48v lifepo4 is 16s so everything for 48v 16s is common if you want 17s or 15s lifepo4 YOU will have to be made special just for you. Charger and BMS and controller, custom made. Just for you.
So don't do it or learn the hard way. You are difficult custom BMS custom charger custom low voltage cutoff custom high voltage cutoff. WHY or maybe you should just go do it 15s and you'll learn through pulling out your hair. Do you still have any hair left.

Did you look bat the tread I popped up just for you ?
A123 20ah cell pouch build and discussion.
As A123 make many different ah and chemistries so make sure you're looking at the right ones.
Never never ever buy sells that have laser rewelded tabs make sure you ask make sure you get a picture make sure you know before you buy that these aren't ripped out of another module and have tabs laser rewelded you can tell by the laser welds on the bottom of the tab that look like railroad tracks do not buy these do not use these cells. Druthlede build...

999zip999 said:

Did you look bat the tread I popped up just for you ?
A123 20ah cell pouch build and discussion.
As A123 make many different ah and chemistries so make sure you're looking at the right ones.
Never never ever buy sells that have laser rewelded tabs make sure you ask make sure you get a picture make sure you know before you buy that these aren't ripped out of another module and have tabs laser rewelded you can tell by the laser welds on the bottom of the tab that look like railroad tracks do not buy these do not use these cells. Druthlede build...

Click to expand...

HI zip yes i looked at the thread as i wrote above those 123 20ah pouch are 496g if im not mistaken
496 g so 15x this = 7.44 kg. that is too heavy to carry for my need(short distance)
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i read the two links you pasted.
one has 252g and the other 261 but they seem to have the same spec. i dont understand why.
has this shop a good reputation?
With alibaba aliexpress i kind of feel uncertain to go with a non reputable seller as it becomes a mystery to know what your are getting with them. i do like that they use screws but if the cells are dangerous it is a no go.

i wonder if there are smaller reputable life po4pouches that can give 30A continous.

sharinginfos said:

i read the two links you pasted.
one has 252g and the other 261 but they seem to have the same spec. i dont understand why.
has this shop a good reputation?
With alibaba aliexpress i kind of feel uncertain to go with a non reputable seller as it becomes a mystery to know what your are getting with them. i do like that they use screws but if the cells are dangerous it is a no go.

Click to expand...

Probably it`s because screw terminals weight. They also add 15mm both sides (~30mm) to the length. On aliexpress 32113 4-4,4Ah is more popular format
About OSN Power in A123 thread they are mentioned

A123 makes many different sizes and chemistry.b30amp should not be a problem.
Read the specs. Battery hookup has headways in many different sizes. Screw top.

v85 said:

Found some 26650 30A (10C 3000mAh), weight 85g (so pack 16s1p with bms - around 1,5kg) and there is option for soldering tags (Z form for series)

Some calculations:
Pack will be 48V(51.2V) 3Ah, so around 150Wh and with
lets say 1000W 48V motor(20A) will work around 9 min (150/1000) and with 20km/h speed will cover 3km distance

Click to expand...

hi i thought the rule of thumb to know how many km a battery will allow in hill or with baggage is to divide the total watthour per 20watthourpour km. how do you calculate that 150whour end up to only 3 km?

999zip999 said:

A123 makes many different sizes and chemistry.b30amp should not be a problem.
Read the specs. Battery hookup has headways in many different sizes. Screw top.

Click to expand...

hi headway 8ah from battery hookup is 360 g so x 16 equals5.7 kg... that is too heavy that is 12 pounds.

i guess the sweet spot for me would be a battery that is around 2kg to 3 kg lighther would be better
without welding is there a way to achive that?

--
to have an idea, if it take the route of https://eu.nkon.nl/rechargeable/lifepo4/26650.html
16 of them 1p . 2.5Ah each makes 120 watthour.
my 48v xiongda is 350 watt motor 70 lbs luggage(include bike) me 170 lbs.
how many km of average hill would the battery provide? how to calculate?