Turnigy Heaven

[markcycle]

Got 50 hardcase 4S 5000ma 20C packs today
all the cells checked out at 3.79 to 3.85 no dead cells

This will all become a 8P 24S pack 100 volts @ 40AH maybe more if I also use other packs i have around

 

[ohzee]

wow that is something I dream about at times. You are a lucky man.

 

[neptronix]

Wow. that's a lot of kilowatt hours. What madness are you building?

You're gonna choke on this suggestion, but make sure you cycle those on a charger to weed out the duds from the studs.
I will bet you money right now there will be some, with that quantity.

 

[Jason27]

That's pretty sweet.

 

[NeilP]

all the cells checked out at 3.79 to 3.85 no dead cells

There is still time for them to die :?

Yea, gotta believe you got duds in there, or you are one hell of a lucky dude. I bought 14 of them and 8 were great, one total dud, one with dead cell, and 4 had iffy cells..the exact same type of hard case packs you have there

 

[markcycle]

all the cells checked out at 3.79 to 3.85 no dead cells

There is still time for them to die :?

Yea, gotta believe you got duds in there, or you are one hell of a lucky dude. I bought 14 of them and 8 were great, one total dud, one with dead cell, and 4 had iffy cells..the exact same type of hard case packs you have there

I've been buying turnigy for almost 2 years now and have not had your kind of failure rate. Of the 50 packs or so I've purchased (none hardcase) I had two packs fail one with a zero volt cell and one puffed and had low capacity. The one that puffed I may have damaged with a heat gun.

But testing and time will tell the story. I am just glad none of the packs have any low voltage cells for starters, I'm not claiming they are all good. I know the disappointment when you test a pack for the first time and see zero volts, but not in this shipment. On to the next step charge and test each pack.

 

[NeilP]

All my Nano Techs have been fine, just those hard case that I was unlucky with..Got to order more soon for my 5404 motor..thinking 35 series or 36 at 16 or 20 Ah...

 

[markcycle]

All my Nano Techs have been fine, just those hard case that I was unlucky with..Got to order more soon for my 5404 motor..thinking 35 series or 36 at 16 or 20 Ah...

That's a lot of voltage

I've only purchased the cheap 20C packs

 

[rojitor]

I considereded those hardcase for my pack time ago, they are kind of the cheapest solution and the hard plastic is a plus. I hope you find no dead cells, good luck with your project

 

[NeilP]

Well yes, I want a bit more power at the back wheel without having to up the current too much...so volts is the way to go.

I have a 5304 in 26 inch wheel, and at the moment at 100 volt it does max of around 55mph
I have ordered a 5404..but hope Kenny will do it for me as a 5405..slightly slower wind. So, up-ing, so upping the voltage won't give me quite as much speed, but hopefully a bit more torque, Pln on a smaller wheel too, maybe a 17 inch motorcycle rim. 21 inch motorcycle is about the same tyre size as 26 inch mountain bike, so 17 should be about right.
24 FET Lyen controller with 4115's

When I bough thth eNano Tech, it was not with C rating in mind, merely convenience of building the battery pack...and Nano Techs were the only ones that I could get in 10S packs. made for a mcuh more compact pack..i need to take the pack off the bike each night to charge, so it was convenient to have a block of 8 10S batterys

 

[dogman dan]

Turnigy heaven or wiring harness purgatory? That's going to be fun to hook it all up.

I wish they offered 1s 4p hardcase packs. At a good price.

 

[jonescg]

^^^^

I've been thinking about that a lot, Dogman. But then I realise that at 20C, that's 400 A. No series wiring could ever handle these currents without 1.6 mm thick copper plates being used.

 

[markcycle]

Turnigy heaven or wiring harness purgatory? That's going to be fun to hook it all up.

I wish they offered 1s 4p hardcase packs. At a good price.

Wiring not the issue for me, it'll go fast, its the pretesting I have to do before the wiring begins that's a time killer i do have it so the test can be done unattended but of course I'm in the room/shop while they are being tested and charged.

Having a CBAII helps

 

[dogman dan]

So what are you using, some kind of bussbar arangement? I just got this mental picture of a huge hairball of wire and 4mm bullets.

Pretesting is easy enough, with a nice light dirtbike, and quite pleasant. Test em 20s 5 ah at a time.

 

[neptronix]

Turnigy heaven or wiring harness purgatory? That's going to be fun to hook it all up.
I wish they offered 1s 4p hardcase packs. At a good price.

Permanent parallel would be the only way to go here! Can't imagine the spaghetti monster you'd create if you had made proper harnesses

Dogman, the things i would do for large format cells.. I get to run 22S/30AH, so imagine that wiring. I am going to perma-solder all my packs into 10AH chunks, that will help..

 

[markcycle]

permanent parallel its going to be

So far the packs are showing at 1C 4.7 AH with a cutoff at 14 volts I'll show the plots later

I've charged about ten of them and they all are 2/3 charged and balanced out of the box - very balanced so far so good

 

[cassschr1]

I haven't used lipo yet.I was talking to Methods about 4s 6s 8s etc He said get 6s, that works with his boards.Then there would be no rewiring of balance wires etc Pricing it out per cell three, 8s packs seem's better deal,comes with 8g wire too, 30C but not in hard pack of course. IS THE HARD PACK A BIG DEAL?

 

[SamTexas]

So far the packs are showing at 1C 4.7 AH with a cutoff at 14 volts I'll show the plots later

Is that typical or way below expectation?

Considering that they are rated at 20C, wouldn't you expect more than 5.0Ah at 1C?

 

[ZOMGVTEK]

I believe the tests are run from 4.20-3.0V/cell. He discharged to 3.5V, and its unclear as to what the full charge voltage was.

These batteries tend to give very similar useable capacity, irrespective of the discharge rate, as long as its kept below the continuous rating.

 

[liveforphysics]

So far the packs are showing at 1C 4.7 AH with a cutoff at 14 volts I'll show the plots later

Is that typical or way below expectation?

Considering that they are rated at 20C, wouldn't you expect more than 5.0Ah at 1C?

4.7Ah is even a bit high. Designing a pack to use 100% of cell capacity would be extremely dumb. He is discharging to 3.5v, and getting 94% of the rated capacity. This is a perfectly fine test.

In practice, only charging to ~4.1-4.125v and discharging to 3.55-3.6v would be about as deep as you would want to go (~80-85% DOD) for a pack that you're looking to get 4-digit cycle numbers from (as I expect he would be in a motorcycle).

 

[neptronix]

4.7AH is right if you stop discharging as soon as a cell hits 3.5v.
I discharge to when a first cell hits 3.0v, that's how i get 5AH, often 5.1 or so..

Like Luke said, in reality you'll want to stop around 3.6-3.5, but there is a smidge of energy after.. if you must stretch it, AND you have packs with very well matched cells ( in AH and IR ), you can go down to 3.4V no prob.

Also when you set your LVC, you need to account for sag. If you're pushing your pack past 1/4th of it's limit, you're gonna get some pretty good sag per cell on these 20C packs, which means that say.. the cells sag down to 3.5v when they're really at 3.7v.. you hit your LVC and that sucks :/

 

[SamTexas]

I believe the tests are run from 4.20-3.0V/cell. He discharged to 3.5V, and its unclear as to what the full charge voltage was.

These batteries tend to give very similar useable capacity, irrespective of the discharge rate, as long as its kept below the continuous rating.

So if he were to discharge it at 4C to 3.5V, he would also get 4.7Ah? I speculate that he would get less than 4.7Ah because 3.5V would be reached sooner due to higher voltage sag.

 

[SamTexas]

In practice, only charging to ~4.1-4.125v and discharging to 3.55-3.6v would be about as deep as you would want to go (~80-85% DOD) for a pack that you're looking to get 4-digit cycle numbers from (as I expect he would be in a motorcycle).

Is that the recommendation for all types of existing Lithium cell (with 3.7-3.8V nominal), or just RC Lipo?

 

[markcycle]

I charged them to 4.2 for the test, but in everyday use it'll be 4.1 to 3.6 volts.

I'm totally happy with 4.7 AH capacity for a first power cycle. I expect they may even get a small amount better once cycled a few times.

I can't wait to get the ThunderJunk (Thundersky) cell out of my bike.

 

[jonescg]

So Mark, have you convinced Jon to stick some LiPo into his bike yet? That alone would give him 5 seconds a lap!