Suitable battery for an 1800W 48V 38A motor?

[Dr Stowaters]

I have this motor and right now I run it by 4 12V Lead-acid 7Ah batteries wired in series. It's runtime is some minutes and I guess because of the batteries the motor can't fully utilize its 1800 watts (top speed right now is 33 kmh). So I need to buy a 48V lithium battery and I have almost no idea what battery i should buy to get full power out of the engine and a proper runtime (hopefully 40+ minutes). Please guide me with what battery pack i should buy. Im building an electric bike.

My budget is 300 dollars, I live in Sweden.

 

[electric_nz]

The number of Amps will be printed on the controller. If it really is 38A, you will need at something like a 5p (5parallel strings) battery with high power 18650 cells capable of 10A or more each.

For the budget, look at a 14S 5P 18650 battery using high power brand name cells like Samsung 25R, molicell, Murata VTC6, LG HG2 etc. that will be your cheapest and most reliable option. You’ll need a matching charger and preferable a Bluetooth BMS so you can keep an eye on the battery.

Alternatively you can use 21700 series cells, or if it’s a go cart or something with room for a larger battery get something made using repurposed automotive cells.

 

[docw009]

You have a 7AH battery that lasts 15 minutes? If you replaced it with a 48V28AH battery (big big big), you would get an estimated 60 minute run time because it's 4X larger That is how the math works. Run time is proportional to the AH, but there is a lot more to consider.

You should disclose what you're really trying to do. A good 48V28Ah battery will probably cost $600-900 USD. You're running four $20 USD batteries right now. Are you trying to do a racing go-cart. run a small cart, or a fast scooter? Maybe whatever you want won't fit the budget.

 

[Dr Stowaters]

You have a 7AH battery that lasts 15 minutes? If you replaced it with a 48V28AH battery (big big big), you would get an estimated 60 minute run time because it's 4X larger That is how the math works. Run time is proportional to the AH, but there is a lot more to consider.

You should disclose what you're really trying to do. A good 48V28Ah battery will probably cost $600-900 USD. You're running four $20 USD batteries right now. Are you trying to do a racing go-cart. run a small cart, or a fast scooter? Maybe whatever you want won't fit the budget.

I'm building a E-bike, I found some batteries that would maybe work. This one that is probably a lot better but is more expensive, and this one that is cheap and probably a scam.

 

[Dr Stowaters]

The number of Amps will be printed on the controller. If it really is 38A, you will need at something like a 5p (5parallel strings) battery with high power 18650 cells capable of 10A or more each.

For the budget, look at a 14S 5P 18650 battery using high power brand name cells like Samsung 25R, molicell, Murata VTC6, LG HG2 etc. that will be your cheapest and most reliable option. You’ll need a matching charger and preferable a Bluetooth BMS so you can keep an eye on the battery.

Alternatively you can use 21700 series cells, or if it’s a go cart or something with room for a larger battery get something made using repurposed automotive cells.

I found this one and another one that was a lot cheaper that is probably a scam.

 

[E-HP]

I'm building a E-bike, I found some batteries that would maybe work. This one that is probably a lot better but is more expensive, and this one that is cheap and probably a scam.

The second pack description is laughable. The first pack is better as long as you manage expectation. 50A is optimistic from 13S8P pack of generic Chinese cells. 40A is doable on peak with a decent amount of voltage sag. 35A is probably a more realistic rating for the pack (based on my last UPP 8P pack with generic cells).

 

[Svooper]

I have this motor and right now I run it by 4 12V Lead-acid 7Ah batteries wired in series. It's runtime is some minutes and I guess because of the batteries the motor can't fully utilize its 1800 watts (top speed right now is 33 kmh). So I need to buy a 48V lithium battery and I have almost no idea what battery i should buy to get full power out of the engine and a proper runtime (hopefully 40+ minutes). Please guide me with what battery i should buy.
My budget is 300 dollars, I live in Sweden.

I found this battery, will it be sufficent?

 

[neptronix]

The product under google translation has a ton of specifications that don't match each other. This is extremely likely a fraudulent listing. There's a ton of this crap on amazon, and trust me, you don't want any of it.

https://www-amazon-se.translate.goo...l=auto&_x_tr_tl=en&_x_tr_hl=en&_x_tr_pto=wapp

This is also extremely cheap for a battery of this size. You can't even build a battery of this size yourself from cells at this price... unless you used recycled cells, which this probably contains. If that's the case, a battery like this is probably very dangerous.

It doesn't even have a balancing circuit so it won't last long.

To get a pack that isn't a fireball in the making of this size, you'll need to pay quite a bit more money than you're expecting. Or you want a pack with low capacity but very high output.

Either the budget needs to change, or your expectations

 

[Svooper]

The product under google translation has a ton of specifications that don't match each other. This is extremely likely a fraudulent listing. There's a ton of this crap on amazon, and trust me, you don't want any of it.

https://www-amazon-se.translate.goog/batteri-Lithium-Elcykel-Anti-korrosion-slitstark/dp/B0CPDDRBQF/ref=mp_s_a_1_14?crid=3GLXD7RDSOPN7&dib=eyJ2IjoiMSJ9.W-DRXnXPK-iTQ7WPFZHrP-RpL0Y4WzXtN5TXQz8GYSHzsF_fKh3nB4fbTjRUj-OYLFb7kpO3MPivL9bx_U5ZmuFeHKGU8Br8O9wCIdr64bky_TVC7Ll3_Qa6DWv93ZfcpR1cl0jEKxQzEEC_rIshsnaMIOOJj5FrKCAmgsPXtp-XNmxkxohvvHiqqSG7B84rYJgy8PwdMbjmLT6-o96PPQ.WyU0O8yio7MaT5BkTnreQXN8Op99A57N5AU1wQOG1oM&dib_tag=se&keywords=48v+lithium+batteri&qid=1708268838&sprefix=48v,aps,877&sr=8-14&th=1&_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=en&_x_tr_pto=wapp

This is also extremely cheap for a battery of this size. You can't even build a battery of this size yourself from cells at this price... unless you used recycled cells, which this probably contains. If that's the case, a battery like this is probably very dangerous.

It doesn't even have a balancing circuit so it won't last long.

To get a pack that isn't a fireball in the making of this size, you'll need to pay quite a bit more money than you're expecting. Or you want a pack with low capacity but very high output.

Either the budget needs to change, or your expectations

Okay thaks for clearing things up for me. Where can I find batteries with lower capacity but high output? What sites do you recommend.

Edit: I browsed around jag35 and found many cheap 48v lithium-io batteries with pretty high capacities like this one, are those a scam because I heard that jag35 is a good website for batteries.

 

[Az.]

You have go-kart motor and planning to install it on a bike? It doesn't make any sense to me. There are so many ready made hub and mid drive motors ready to install on a bike.

Can you post some pictures of this project of yours?

 

[neptronix]

A majority of battery listings on the internet are garbage and close to fraudulent.

Look for a brand that has a website and has been around for more than 5 years ( this quickly eliminates 90% of truly crappy products ). These big market sites are where a majority of the crap is.

I would almost recommend UPP for your price range, but i think they are below the quality and safety minimum.

This is what i'd buy, personally, for this case:
EM3ev 52V (14S7P) Hard Case Ebike Battery Pack | EM3ev

To help you find what you need, what kind of battery pack do you have already? is this a bicycle, a scooter..?

 

[Svooper]

A majority of battery listings on the internet are garbage and close to fraudulent.

Look for a brand that has a website and has been around for more than 5 years ( this quickly eliminates 90% of truly crappy products ). These big market sites are where a majority of the crap is.

I would almost recommend UPP for your price range, but i think they are below the quality and safety minimum.

This is what i'd buy, personally, for this case:
EM3ev 52V (14S7P) Hard Case Ebike Battery Pack | EM3ev

To help you find what you need, what kind of battery pack do you have already? is this a bicycle, a scooter..?

Its a bike and the battery I alredy have is 4 20$ 12v 7ah agm batteries wired in series. Thank you for hemping me and I will check in the upp website

 

[Chalo]

JAG35 batteries are all used or surplus, so they are usually better quality than we can afford otherwise, but possibly old enough to be a problem. You don't really know until you get one and check it out. The website usually doesn't volunteer information about which packs are excellent and which ones have problems.

 

[neptronix]

Yeah, you could definitely save some money buying a used battery, but, you will need to invest in some skills and tools to make best use of them. The question is, how willing are you to put work into saving money

 

[E-HP]

Why two threads with two different usernames?

 

[Svooper]

Why two threads with two different usernames?

Did not know my friend already posted here

 

[Svooper]

Yeah, you could definitely save some money buying a used battery, but, you will need to invest in some skills and tools to make best use of them. The question is, how willing are you to put work into saving money

How much work are we talking about? I am willing to take the cheaper rout if its just a couple of days of hassle

 

[neptronix]

Did not know my friend already posted here

Must be a really close friend, maybe identical twin?





Please just be honest

 

[Svooper]

Found this battery on upp. Will that work or is it also a scam and a cheap battery?

 

[Svooper]

Must be a really close friend, maybe identical twin?

View attachment 347765

View attachment 347764

Please just be honest

My friend posted this on reddit, i asked him to do that because I wasnt home. Opened his thread and saw a comment suggesting asking here. Copied the exact reddit post here. I saw his post right after i posted, sorry. Here is discord messages indicating that he posted on reddit

 

[E-HP]

Must be a really close friend…

I suggest combining the threads (although I don’t know if you have limitations when you have two different authors). If the friend isn’t going to be a regular contributing member, then possibly deleting the extra account would keep it tidy (just a thought, not a suggestion).

 

[Svooper]

Re named the thread, hope it helps a little to keep things seperated

 

[amberwolf]

I merged the two threads to keep all the info in one place, so that those helping can see everything and not miss any required info.

 

[E-HP]

Found this battery on upp. Will that work or is it also a scam and a cheap battery?

I believe my 10:56 AM comment above may be applicable.

 

[gromike]

For my first ebike conversion, and not knowing much, I bought a UPP battery. Now that I know something about battery construction I wouldn't again buy one. That said, I have a year and a half of 1500 trouble free miles of use with it.