36V 500AH battery pack for e-bike knowledge and options wanted!

[LittleBluesVibe]

Hello there,

I currently use a Fiido D4S which has a 10.4AH battery which lasts around 4 or so hours (yes I am heavy 238lbs) I have been looking into making my own battery bank for my e bike for a while now but the amount of 18650 battery's I would need to get anywhere near 50+ AH is just crazy, so after coming across " DIY Solar Power with Will Prowse " and looking at his videos that he has uploaded I found these battery's https://www.aliexpress.com/item/100...a2g0o.store_pc_home.productList_2820688.pic_9 now from what I can tell ( basic knowledge ) if I connect 10 of these in series I should be able to make a 36v 500AH battery pack which should work with my e bike. Now the question is would it work? I'm just putting 1 and 2 together at the moment but I am willing to learn and build it. All input an help good and bad will be greatly appreciated.

 

[Pyrofx]

10 in series gives you 32v at 50ah.

 

[chrisski]

if I connect 10 of these in series I should be able to make a 36v 500AH battery

THat would be a 50 ah battery. I think you have a typo.

I do not know about e-bike discharge rates. This doesn’t really say, but this appears a constant discharge rate of 1C, can withstand 2C, and pulses up to 3C. If the whole is similar, than on the right track.

 

[LittleBluesVibe]

@Pyrofx

The listing states that they are

3.7V 50Ah​

so its not as simple as 3.7*10? could you explain how you got 32v please.

@chrisski

each battery is 50 ah if I had 10 in series it would not add up to 500 ah?

 

[LittleBluesVibe]

When I get up I will take a photo of the controller which is installed in the bike. which should allow us to explore more.

 

[Pyrofx]

Ok 37 volts. Series makes volts. Parallel makes amps

 

[chrisski]

A 12 volt battery with 100 ah of power has 1200 watts (12*100)
A 24 volt battery with 100 ah of power has 2400 watts (24*100)

Both have 100 ah of power, but it takes two 12 volt 100 ah to get the same watt Hours.

 

[LittleBluesVibe]

@Pyrofx

Ah ty that explains allot.

@chrisski

ok so you are saying 3.7v @ 50ah = 185watts this is for each of those batteries. and if I had 10 in series it would be 1850 watts, but even if I had 10 3.7v 50ah battery's in series it would still only total 50ah for the pack>?

 

[LittleBluesVibe]

@chrisski

Ah I see the typo I forgot to mention battery "PACK" (Ty)

 

[Pyrofx]

@Pyrofx

Ah ty that explains allot.

@chrisski

ok so you are saying 3.7v @ 50ah = 185watts this is for each of those batteries. and if I had 10 in series it would be 1850 watts, but even if I had 10 3.7v 50ah battery's in series it would still only total 50ah for the pack>?

Yes. 100 in series would still be 50ah

 

[LittleBluesVibe]

@Pyrofx

Ok so how is it when you have 2500mah 18650's 10 in series and 4 in parallel you get a 10ah battery pack?

 

[MisterSandals]

ok so you are saying 3.7v @ 50ah = 185watts

185Wh (watt hours)

 

[MisterSandals]

@Pyrofx

Ok so how is it when you have 2500mah 18650's 10 in series and 4 in parallel you get a 10ah battery pack?

10Ah needs a voltage to be meaningful for these calculations. 37V?

2500mAh = 2.5Ah @ 3.7V
2.5Ah x 10 in series = 2.5Ah @ 37V
2.5Ah x 4 in parallel = 10Ah @ 37V

 

[Pyrofx]

I dont want to sound like a dick. But this is basics. Please ask through each phase of what your doing for a procedure check

 

[LittleBluesVibe]

@Pyrofx

I understand what you are saying hence why I am asking all the questions.


My goal is to make a battery pack that is 36v and 50 ah + and was wondering if the battery I linked would work for this and if it can what would be the best setup. or would I just be better off sticking to the 18650's which would cost around £1000 samsung 25R

 

[Pyrofx]

Ouch 1k quid.
These would work fi e if you had the room .
I didnt look at the seller , but aliexpress = run away.

 

[LittleBluesVibe]

The seller is " LiitokalaVariCoreFlagship Store " some of there products have over 20k orders, and 99% of reviews are good main thing is most cells are about 5-10 less AH than stated. Other than that looks good tbh.

 

[Short_Shot]

@Pyrofx

The listing states that they are

3.7V 50Ah​

so its not as simple as 3.7*10? could you explain how you got 32v please.

@chrisski

each battery is 50 ah if I had 10 in series it would not add up to 500 ah?

3.65v is the absolute maximum voltage.

Nominal voltage is only 3v per cell.

You will actually only have a "30 volt" pack with 10 cells. You will need 12 cells for a 36v nominal pack.

And series doesn't add up like that. Voltage goes up, Ah stays the same. 10 cells is a nominal 30 volt 50ah pack.

 

[Short_Shot]

The seller is " LiitokalaVariCoreFlagship Store " some of there products have over 20k orders, and 99% of reviews are good main thing is most cells are about 5-10 less AH than stated. Other than that looks good tbh.

Don't buy anything from them. Most of us have been getting used cells that are missing capacity the last several months from this seller.

 

[chrisski]

Looking at the specs, these are 3.7 volt cells, well maybe 3.65, and are rated a bit different than the lithium phosphate I use: