Building A Ludicrous 14s2p SPIM08hp battery

[SafeDiscDancing]

Any issues with heat? I would like to push them as hard as I can with a 150a controller and QS2000w motor. Would I be okay to store them in a water tight box, or do they need some air flow?

150a for an 8ah pouch cell?

That's roughy 160/8 = 20C.

I'm guessing "No" not a good idea. Maybe if you parallel two 8ah cells like over at Battery Hookup where they sell the hardware including the bolts and clamps you could pull off 10C... but no way it will survive 20C for long.

And if the temperature is below 50 degrees expect to have to ride them once just to get them up to full temperature and power. When cold the voltage drop is much higher so you feel like the battery is closer to empty despite being full.

For what you want I'd say something more like 20ah would be good... pouch cells around 30ah are the new "standardized sizing" for all future LG Chem pouch cells so I'd look for those.

Those are roughly 14" long, 4" wide, and about half an inch thick.

[SafeDiscDancing]

Let's look at what Battery Hookup says about their 16ah "combined" cells:

https://batteryhookup.com/products/2x-s ... ded-insert

THESE LITHIUM ION CELLS ARE 2000 CYCLE RATED.

Material Li-ion

module specs

Typical capacity 16AH
Nominal Voltage 3.7V
Weight : 1 LB 12 OUNCES
Dimensions of cell body: 9x138X190mm
Dimensions of cell with tabs 9x138X210mm

Dimensions of cell module: 6 5/8" x 5 5/8" by 3/4"

Internal Resistance ≤0.8mΩ

Max Charge Rate 240A
Recommend Continuous Discharge Rate 400A
Pulse Discharge Rate（3 seconds） 800A
Fully Charged voltage 4.2V
Discharge cut off voltage 2.5V
Working Charge Temp 0~50°C
Working Discharge Temp –20°C~50°C
Storage Temperature –20°C~50°C

-------------

So they seem to think the 16ah idea would deliver 400A with no problem.

In my experience I personally think that's not valid "unless" the cells are warmed. Once you get them up to 70 degrees or more then the numbers are realistic. When fully warmed up there is almost no voltage sag and you get pretty close to what voltage exists at rest.

This makes me think that you really should use the Grin simulator and try different values for internal resistance and then see what it does to performance. Another fun thing to look at.



My guess is if you went for a single 8ah cell in series then their stated current would be 200 continuous which if you have a goal of 150 amps that's cutting it pretty close and when cold I "know" that just 50 amps and you are already getting significant voltage sag.

We had a stretch of near zero temperatures near christmas and I wanted to ses how the batteries handled it. So the first 20 minute ride was just to begin the warmup. I then charged at 35 amps. Then rode again. Second ride is already good. By the third or fourth the battery was performing perfectly.

[Quinc]

Thank you for the info! I have the 16ah packs from BH. It is currently 65ish degrees right now in the sun and by the time my project is finished it should be in the 70s-80s.

I am all for different batteries, but these seem hard to beat for power and price.

[SafeDiscDancing]

Thank you for the info! I have the 16ah packs from BH. It is currently 65ish degrees right now in the sun and by the time my project is finished it should be in the 70s-80s.

I am all for different batteries, but these seem hard to beat for power and price.

They like being driven hard. And when cold they really suffer a lot, but they warm up quickly.

I think what happened is these were produced for backup generators in very cold conditions and experience taught them that when cold they are not that great. So my "guess" is they are replacing them with something else and that's why we get them at the big discount.

My experence is they are really strong cells. Warm them up and then run them hard.

And the price is fantastic. I bought mine a year ago and from an eBay source which quickly disappeared. Mine are a random mix of cells with differing capabilities. Buying from Battery Hookup should mean you get cells from the same batch which is better.

[DogDipstick]

They like being driven hard. And when cold they really suffer a lot, but they warm up quickly.

I think what happened is these were produced for backup generators in very cold conditions and experience taught them that when cold they are not that great. So my "guess" is they are replacing them with something else and that's why we get them at the big discount.

My experence is they are really strong cells. Warm them up and then run them hard.

For what you want I'd say something more like 20ah would be good... pouch cells around 30ah are the new "standardized sizing" for all future LG Chem pouch cells so I'd look for those.

Those are roughly 14" long, 4" wide, and about half an inch thick.

NOT sure what "standardized" cell you are talking bout. I got about 8kWh of NEW LGZ 25Ah cells that are from GM. THEY are not 14 inches long. The size is standard ( 6 x 10, not 14 x 4). I know atr least 10 EV with this cell form factor. Perhaps you have a cell name, theese """ new "standardized sizing" for all future LG Chem pouch cell"""" you speak about?

SPIOM?
Nah they weak... for the volume they encompass. Huge. Bulky. Struggle to get 750wH on an ebike, let alone the 2-6 kWh some people do oin powerful builds. Like 100wH/Kg. Less even. Sure in a stationary install, volume does not matter. ON a bike, volume matters most next to aero. US highway approved EV cells can push 180wH/kG easily ( DENSITY). New 18650 can do 220. Even the ( brand new ) ones TOM gave me are getting old in one year just sitting. Under test, they falter. The Chevy cells I like will TROMP them. There is NOT alot of copper in these SPIM08 cells.

10C+ Chevy cell, 30C+ peak, greater than SPIM08HP chineese cell. Seen some pull 4000A on a 7000A controller on Chevy cells. Never saw numbers like that from these SPIM. Frock chineese cells. Recycle( from buyers in ) in your own country, you will probably find better in your countries EVs. Look at it. How can they ship from china, sell from Bethlehem,, and ship again to a third or fourth buyer....down the line.. IF these cells are valuable.. for the cost they are.

They are not really 0.0008 Ohm. BAHAHAHAHAHAHAHAHAHAAHAHAHAHAHAHAHAHA noope. YOu can see the 100hz AC bridge tests that I posted. Earlier. A stress test should not be very hard to destroy the cell unusable @ 400A in a cycling datalogfgger. I HATE that kind of misinformation and gimmickry.. State this, sell that. No one has tested 400A on these on datalog? Eh? Cycled them for ever? No proof? We should be having proof by now, ya know. Some buyer will be dissapointed wqhen they get 3-5mOh from the cell advertised as a "<0.0008oH" cell.

But still, people love these guys. SPIM08. I am a geek, and very critical.

I got 24 of these if anyone want them for cheapps. Hell I'll give em away if you pick em up. They were freee to me. I tried to give a poor guy in Canada them, free, but he couldnt cover the shipping.

Internal Resistance ≤0.8mΩ

Lies.

[SafeDiscDancing]

Lies.

I have thousands of miles on these cells and I can confirm that until they warm up to full operating temperature they are pretty lame.

Once you get them warmed up I think their claims are probably about right.

The lesson about these cells is they need to get run hard or they fall really short of expectations.

And you NEED to be thinking fast charging with these.

The way I use them it's like a Supercapacitor where I charge them in 20 minutes and then ride them hard for twenty minutes over and over all day.

My area has about ten miles of high quality asphalt road with plenty of exotic up and down hills and fun turns so it's like having my own racetrack.

Each 300 wh recharge is gone in 20 minutes so... 3x is 900 wh @ 1 hour... so I'm "averaging" 900 watts all day long. (while riding)

And let me add... the fact these cells are "reluctant" to get fully up to speed is probably why they are durable. If your battery is too willing to spew it's energy then it's probable that it can be ripping itself up doing that. These cells need to be brought up to operating temperature or they act to defend themselves with increased resistance.

[pullin-gs]

I have these in two separate projects.
2018 I built a 3S3P pack for my E-Kayak. Still going strong.
2019 I built two 12S1P packs for a pair of E-Trikes. Also performing well.
That said, WH density is not very good.
PS: I live in Florida, so packs are pretty warm to start with.

[SafeDiscDancing]

That said, WH density is not very good.

The jelly roll cells in cylinders do better in total capacity.

These pouch cells simply scream as they perform at high C rates when warm.

And in Florida you never see cold so they are a heck of a deal for the price.

[pullin-gs]

These pouch cells simply scream as they perform at high C rates when warm.

And in Florida you never see cold so they are a heck of a deal for the price.

I got my introduction to cooler-weather performance the past two days.
At 40-degrees, voltage sag is terrible! I had no idea. Cruise speed on my 12s1P build went from 28mph down to 24 on full pack. Hill performance even worse.
No big deal, otherwise I love these cells!
When warm, performance (low voltage sag) is BETTER than my 12S6P Sanyo 29E 18650 pack for first 10 miles.

[SafeDiscDancing]

I got my introduction to cooler-weather performance the past two days.

As I understand the story these cells were being used in backup generators.

So imagine the power goes down and it's freezing cold outside... these cells would be a terrible choice.

This is in my opinion why they are replacing them.

Get them warm and run them hard and they love it.

[Quinc]

Building my first pack. Doing 20s2p. Would 1/8" aluminum busbars be enough for max discharge of 150-200amps? (qs-120 motor)

I also have some 3/4" copper pipe I could smash and cut, but read there is a chemical reaction with the copper and not to use it?

IMG_20220211_141500172.jpg (137.5 KiB) Viewed 227 times

[thundercamel]

Just read a relevant thread here: viewtopic.php?f=2&t=114997
Has to do with the surface of aluminum corroding, so the specific connection point needs to be treated to not have resistance build up over time.

Here are some other old threads as well:
viewtopic.php?t=47319
viewtopic.php?t=9174

[Quinc]

Just read a relevant thread here: viewtopic.php?f=2&t=114997
Has to do with the surface of aluminum corroding, so the specific connection point needs to be treated to not have resistance build up over time.

Here are some other old threads as well:
viewtopic.php?t=47319
viewtopic.php?t=9174

Thank you!

[Quinc]

Next newb question. Any reason not to shrink wrap these batteries?

[SafeDiscDancing]

Next newb question. Any reason not to shrink wrap these batteries?

I put a single layer of fiberglass (using resin like building a boat) around each cell.

That gives plenty of compression and weighs next to nothing.

Some retard can now chime in with:

"Well why not use carbon fiber it's stronger."

Yeah... but who cares... I'm not about throwing $$$ around for no reason.

And actually I taped the edges down first to get the width a little tighter before I added the fiberglass.

It's very snug. No problems.

[Quinc]

Next newb question. Any reason not to shrink wrap these batteries?

I put a single layer of fiberglass (using resin like building a boat) around each cell.

That gives plenty of compression and weighs next to nothing.

Some retard can now chime in with:

"Well why not use carbon fiber it's stronger."

Yeah... but who cares... I'm not about throwing $$$ around for no reason.

And actually I taped the edges down first to get the width a little tighter before I added the fiberglass.

It's very snug. No problems.

That is a great idea! Do you have any pics? I normally use 4 and 6oz s-glass for my fiber needs. carbon cost too damn much.

[SafeDiscDancing]

That is a great idea! Do you have any pics? I normally use 4 and 6oz s-glass for my fiber needs. carbon cost too damn much.

Sorry, no pictures.

I used the light weight cloth... 4 or 6 oz sounds about right. Whatever was at ACE Hardware. (Bondo brand)

Just one layer is enough.

Then I assembled the SPIM08hp 12S into a pack and gave it a fiberglass exterior which was also lightweight.

After that I added the mounting attachments (aluminum sheets) and that was it.

Very light weight overall.