Building a batterypack for a racecar

[CincoDeMayo]

Hi guys,
I visit this forum all the time for vaping tips and it has helped me quite a lot, thanks for that (especially mooch)

My question now isn't related to vaping, but I think you veterans might have useful tips!

So I'm building a batterypack for a racecar and am currently looking for the right cell, since the requirements are quite crazy:

• liquid cooled Li-Ion cells, temperature isn't an issue
  
• ~50 Amps draw per cell, peak 70+ Amps but only for a few seconds
  
• since weight is critical, the capacity must be as high as possible
• 21700 preferred, 18650 if necessary
• more than 100 loading cycles are not required
• total amount of cells: 400-600 (21700)

My favorite cell so far is the Samsung 48G, because of it's high capacity and respectable peak discharge current, but sadly they're not available at my dealer .
I also like the Samsung 30T (also bad availability), the Samsung 40T (not released yet).

Do you guys know any cells that can meet those requirements? They all will be overstrained, but cycle life is not important, performance and light weight is.

Any help would be greatly appreciated, thanks!

Regards Mayo

 

[stols001]

I'm sorry I don't know anything about racecars. LOL. Do you maybe want to find a forum that addresses those issues, because I'm not going to search, but I am sure there are other forums more suited to this kind of question.

Good luck

Anna

 

[zoiDman]

Hi guys,
I visit this forum all the time for vaping tips and it has helped me quite a lot, thanks for that (especially mooch)

My question now isn't related to vaping, but I think you veterans might have useful tips!

So I'm building a batterypack for a racecar and am currently looking for the right cell, since the requirements are quite crazy:

• liquid cooled Li-Ion cells, temperature isn't an issue
  
• ~50 Amps draw per cell, peak 70+ Amps but only for a few seconds
  
• since weight is critical, the capacity must be as high as possible
• 21700 preferred, 18650 if necessary
• more than 100 loading cycles are not required
• total amount of cells: 400-600 (21700)

My favorite cell so far is the Samsung 48G, because of it's high capacity and respectable peak discharge current, but sadly they're not available at my dealer .
I also like the Samsung 30T (also bad availability), the Samsung 40T (not released yet).

Do you guys know any cells that can meet those requirements? They all will be overstrained, but cycle life is not important, performance and light weight is.

Any help would be greatly appreciated, thanks!

Regards Mayo

Building your own Tesla?

LOL

Anyway... If you can't find any Advise here that Points you in the Right Direction, You might try checking out some of the e-Bike/Bike Forums.

I've read some Good (and Not so good) advise on Building/Re-Building Battery Packs for an e-Bike I own.

 

[untar]

Do you guys know any cells that can meet those requirements? They all will be overstrained, but cycle life is not important, performance and light weight is.

There aren't any. What you most likely need to do is built a series+parallel pack like they do for anything that needs high amp draw (eg a cordless drill comes to mind, some can draw peak 150A easy).
By adding cells in series you increase the voltage, by adding them in parallel you increase current draw capability.
Eg you want 7.4V and ~50A output then you could take 4 sony vtc5A, 2 stacked pairs in parallel. You can add a 3rd stacked pair in parallel for even more current.

Even if your cycle life isn't important, I can't imagine you'd want your car to stop dead after 30 seconds or so
This isn't quite the right forum to inform you though, there's RC forums that have people who already did what you want to do. They might know more about powering an RC car than your average bunch of vapers ^^

 

[gandymarsh]

As others have mentioned already. The only way to get that many amps out of 18650 batteries is to connect 2 or more in parallel. There are different ways of doing it depending on what you are trying to accomplish.

I recently built an ebike so I've been watching videos to learn as much as I can. This is a youtube channel that has lots of info about building battery packs.

EbikeSchool.com

 

[classwife]

Since this has nothing to do with vaping it does not belong in General Vaping Discussion.
Moved to The Lounge.

 

[Baditude]

 

[BrotherBob]

Do you guys know any cells that can meet those requirements? They all will be overstrained, but cycle life is not important, performance and light weight is.

Welcome and glad you joined.
Sounds like your may require cells that give you max amps at start output. A good vape battery ("We are using IMR or INR Li-Ion batteries--mostly use generic 3.7 volt lithium ion cells") may be built to other applicable spec's, you may be in the right church but in the wrong denomination.
Could PM @Baditude for clarification .Baditude's below answer may not be applicable to your requirement.
Re: Alien 220w Questions

 

[CincoDeMayo]

Thanks for your answers, will keep you updated.
If the 21700 are not available, the VTC6 will be the best choice imo.
By the way: 50 amps go through every cell in the pack, not through the whole pack combined
Tesla ain't no competition

 

[ENAUD]

Thanks for your answers, will keep you updated.
If the 21700 are not available, the VTC6 will be the best choice imo.
By the way: 50 amps go through every cell in the pack, not through the whole pack combined
Tesla ain't no competition

Are you going to build in an ejection seat?

 

[zoiDman]

...
By the way: 50 amps go through every cell in the pack, not through the whole pack combined
Tesla ain't no competition

Might want to Re-Think your Battery Layout. Cus I don't know of Any 18650 ~ 21700 Cell that is going to be about to handle 50 Continuous Amps.

And 400 Cells Melting Down at the Same Time is sure to get you a Spot on the News. Or one of those Cable Shows that start with "Don't Try This At Home".

LOL

 

[CincoDeMayo]

Since they are all liquid cooled they actually can, we've tested it. It's probably going to be below 50 Amps anyway, just wanna make sure.

If any crazy new cells are coming up and you guys know about it, let me know!
Thanks

 

[zoiDman]

Since they are all liquid cooled they actually can, we've tested it. It's probably going to be below 50 Amps anyway, just wanna make sure.

If any crazy new cells are coming up and you guys know about it, let me know!
Thanks

You know best. Just be Careful. That many Cells in one place has a Tremendous Amount of Potential Energy.

What type out Output Voltage are you looking to achieve?

 

[CincoDeMayo]

Around 300V maximum voltage. The cells will be separated into 5+ segments which are fireproof and electrically non-conductive. The safety measures in this pack will be immense, don't worry about it.

Sure high power cells would be more suitable for this performance demand, but since weight is everything, we will try and go for high capacity cells.

 

[ENAUD]

Around 300V maximum voltage. The cells will be separated into 5+ segments which are fireproof and electrically non-conductive. The safety measures in this pack will be immense, don't worry about it.

Sure high power cells would be more suitable for this performance demand, but since weight is everything, we will try and go for high capacity cells.

I'd honestly love to see whatever you are building running down the track. Are you planning on having video and possibly posting anything on YouTube or another platforms?

 

[zoiDman]

Around 300V maximum voltage. The cells will be separated into 5+ segments which are fireproof and electrically non-conductive. The safety measures in this pack will be immense, don't worry about it.

Sure high power cells would be more suitable for this performance demand, but since weight is everything, we will try and go for high capacity cells.

Yeah... That is a Cardinal Rule of Racing. If you want to go Faster, make it Lighter.

 

[zoiDman]

I'd honestly love to see whatever you are building running down the track. Are you planning on having video and possibly posting anything on YouTube or another platforms?

Check this out.

An 11.4s / 114mph Street Legal Datsun.

 

[ENAUD]

Check this out.

An 11.4s / 114mph Street Legal Datsun.

Looks like he used soft pack (bag) batteries in his block packs. Lots of weight savings over steel can batteries.

go to the 3:53 / 3:54 time and freeze it to see the internals of the cells...

 

[zoiDman]

Looks like he used soft pack (bag) batteries in his block packs. Lots of weight savings over steel can batteries.

go to the 3:53 / 3:54 time and freeze it to see the internals of the cells...

I could have the White Zombie guy mixed up with someone else. But I believe he started out using CR123A Batteries.

But moved to Li-Po Packs to save weight like you said.

 

[CincoDeMayo]

I'll post a link to some footage if I remember! Gonna be a while though until the damn thing drives