Samsung 25R/LG 18650HE2/ Sony VTC5 high power 18650 battery

[madin88]

EDIT : FORGET EVERYTHING, I just read SONY doesnt make VTC5 anymore ... Then, they are fake ones.

is this true?

 

[ohzee]

That's nice! Now you see why they don't do it the right way, too much work for them

No doubt. I'm just glad I posted the pic on here and had it pointed out otherwise id have had some more dissapointments im sure.

Approximately 100 cross connects of copper on those batteries. After the first one tho it at least went a bit faster.

Hopefully it's ok to use 8 gauge to connect them together on very short runs and then wire thru a double c63 circuit breaker
that's suggested with the adaptto. So close.

 

[riba2233]

Yeah that should be fine

 

[okashira]

It helps to be able to weld copper.
I weld 0.1mm copper stacked right on top of nickel. Works fine.
The downside is the 0.1mm copper is much more fragile then 0.2mm nickel. I am considering potting it after inspection and testing of packs...

 

[riba2233]

Yes, that really helps! I'm going to use similar approach on my next packs. It's because you can't solder between cells when you have these holders.

 

[dbaker]

How about a layer of foam sheet? It would make it easier to repair the pack if a cell fails.

 

[okashira]

How about a layer of foam sheet? It would make it easier to repair the pack if a cell fails.

Well, one of the advantages of these Tesla cells is that we shouldn't have to worry about a single cell failure.
However... by "pot" I just mean a thin coating of flexible epoxy over the stacked copper sheets so the welds are protected from vibration. And maybe use some to assist in strain relief for leads. It should still be repairable.

 

[alexis57]

And what about HE2 from LG ?
I can buy on ebay or aliexpress real ones for 6.2$ each. (shipping is included in this price)
I could try my motor with only 26 batteries. 13s2p

Do you know what is better ?
- BMS with just a power supply (charger) (Does the BMS know how to charge the battery ? constant current then constant voltage)
- A balance management charger ? Like the imax B6

Hello, I have a real source for Sony cells, I have VTC4 and VTC5 on Stock. Do you want to see a pic. from the real VTC5?

Thank you very much but it's okay, I won't buy Sony cells.

is this true?

Yes Sony doesn't make any cells, it's another manufacturer but we don't know ... And, I don't know if they are really fake but in doubt, I won't buy. (the unity price is really low...)

 

[riba2233]

And what about HE2 from LG ?
I can buy on ebay or aliexpress real ones for 6.2$ each. (shipping is included in this price)
I could try my motor with only 26 batteries. 13s2p

Do you know what is better ?
- BMS with just a power supply (charger) (Does the BMS know how to charge the battery ? constant current then constant voltage)
- A balance management charger ? Like the imax B6

I think that's expensive, 25R are cheaper and have better chemistry:

http://eu.nkon.nl/rechargeable/18650-size/samsung-18650-inr18650-25r.html

Now, don't even think about imax b6, buy a bms and a normal charger. BMS can only turn charger on or off, so you need charger or power supply with CC/CV profile and correct end voltage.

 

[alexis57]

OMG thank you very much !
Since I'm in Japan ( outside EU, it's another website ) http://ru.nkon.nl/samsung-18650-inr18650-25r.html
Special price 3.75€ but I'll buy more than 20 then 3.6€ each ...
112.6€ with shipping ! only 4.33€/unit
It's amazing, batteries are real ones ?!
I even could buy more than 26...

Oki, I was thinking about IMAX B6 + BMS (for me a BMS for my battery pack is not an option).
Then I'll buy a BMS 13s but could you help me for the charger ? Which one is good ?
I'd like to charge them with 1.25A or 2A max. (or choose the current)
This one ? ( I cannot choose the current) http://www.batterysupports.com/468v-48v-546v-4a-lithium-ion-lipo-battery-charger-13s-13x-36v-p-168.html

 

[riba2233]

Yes, they are real, no doubt about that!

Why cant you use BMS? Look at this one, it's cheap, it works good (already bought three), and very easy to connect, and very small.

http://www.ebay.com/itm/Battery-Protection-BMS-PCB-Board-w-Balance-for-13-Packs-48V-Li-ion-Cell-max-25A-/251497839451?pt=LH_DefaultDomain_0&hash=item3a8e707b5b

Charger is good, you probably don't need adjustable current, you just need correct voltage (54.6 V for 13S).

B6 imax is slow, and it's not precise, you can use it for some testing, but for real life use, I personally wouldn't.

 

[alexis57]

Of course I will use BMS !!
But charging with 4A is good for the battery life ? (I think for the 25R, 4A is the maximum allowable)
Anyway, Thank you very much ! I'll buy my batteries tomorrow !! I'm still suprised lol it's so cheap...

 

[riba2233]

You're welcome! 4 A is max per cell, so if you have 2 cells in parallel, and 4 A charger, each cell will see only 2 A which is ok.

And don't be surprised, that's realistic price, others are just inflating the price.

 

[Nobuo]

It helps to be able to weld copper.
I weld 0.1mm copper stacked right on top of nickel. Works fine.
The downside is the 0.1mm copper is much more fragile then 0.2mm nickel. I am considering potting it after inspection and testing of packs...

How do you weld copper tabs with not getting the poles stick to them?

What kind of poles do you use to weld cooper, a silver made ones?

 

[Nobuo]

It helps to be able to weld copper.
I weld 0.1mm copper stacked right on top of nickel. Works fine.
The downside is the 0.1mm copper is much more fragile then 0.2mm nickel. I am considering potting it after inspection and testing of packs...

How do you weld copper tabs with not getting the poles stick to them?

What kind of poles do you use to weld cooper, a silver made ones?

 

[riba2233]

I use regular 6 or 10 mm2 solid copper wire for electric installations. It works well, you only have to be sure that the electrode surface is sooth and rounded.

 

[Nobuo]

It helps to be able to weld copper.
I weld 0.1mm copper stacked right on top of nickel. Works fine.
The downside is the 0.1mm copper is much more fragile then 0.2mm nickel. I am considering potting it after inspection and testing of packs...

How do you weld copper tabs with not getting the poles stick to them?

What kind of poles do you use to weld cooper, a silver made ones?

 

[okashira]

It helps to be able to weld copper.
I weld 0.1mm copper stacked right on top of nickel. Works fine.
The downside is the 0.1mm copper is much more fragile then 0.2mm nickel. I am considering potting it after inspection and testing of packs...

How do you weld copper tabs with not getting the poles stick to them?

What kind of poles do you use to weld cooper, a silver made ones?

For the welds in the pic, I was actually using copper.
The trick is to use a good amount of pressure... more then you would for nickel. More pressure reduces electrode to copper contact resistance so that connection doesn't heat up as much.
I also sand the nickel that's already welded with some heavy grit paper to make it extra rough, and clean with alcohol. This ensures the contact resistance between the copper and nickel is higher so the weld can initiate more easily.
Sure you still get some sticking sometimes, but not too bad. remove them by pulling to the side to not put a load on the weld.
Running about 1,200 amps and 8ms pulse time on the 2nd pulse for 0.1 copper to nickel.

I think tungsten copper will work pretty well too. I have some electrodes made from that, but I ran out of heat shink to make my 2nd electrode so I have not tested much. (See here http://endless-sphere.com/forums/viewtopic.php?f=9&t=67661&start=75#p1037222)

 

[Nobuo]

It helps to be able to weld copper.
I weld 0.1mm copper stacked right on top of nickel. Works fine.
The downside is the 0.1mm copper is much more fragile then 0.2mm nickel. I am considering potting it after inspection and testing of packs...

How do you weld copper tabs with not getting the poles stick to them?

What kind of poles do you use to weld cooper, a silver made ones?

For the welds in the pic, I was actually using copper.
The trick is to use a good amount of pressure... more then you would for nickel. More pressure reduces electrode to copper contact resistance so that connection doesn't heat up as much.
I also sand the nickel that's already welded with some heavy grit paper to make it extra rough, and clean with alcohol. This ensures the contact resistance between the copper and nickel is higher so the weld can initiate more easily.
Sure you still get some sticking sometimes, but not too bad. remove them by pulling to the side to not put a load on the weld.
Running about 1,200 amps and 8ms pulse time on the 2nd pulse for 0.1 copper to nickel.

I think tungsten copper will work pretty well too. I have some electrodes made from that, but I ran out of heat shink to make my 2nd electrode so I have not tested much. (See here http://endless-sphere.com/forums/viewtopic.php?f=9&t=67661&start=75#p1037222)

Amazing if it really works, but i guess the sticking could be like a nightmare too much work but, copper tabs would be just perfect for high rated packs.

If you make a video welding copper tabs you make a legend video

thanks for sharing!

 

[riba2233]

LOL

I have already told you a few times, it's not a miracle! It just works... In my case I don't get any sticking any more, just sand the tips. I would make a video, but I'm busy currently, so if okashira wants...

 

[alexis57]

Hi guys !

Last question, I was about to buy my 25R cells but I did a last comparative.

Samsung INR18650-25R
Panasonic NCR18650PF 3.7V 2900mAh

The Panasonic's are cheaper and more capacity.

My motor will be a 1000W (or 750W if I choose BBS02) 48V. My battery pack : 13s4p
I assumed that each battery will deliver 10A. (for a total of 40A : 1920W !! then in reality, it will be less than 10A)

We can see that the Panasonic's are better for capacity..

I didn't compare cycle life neither Energy discharge (but curves are higher... then the energy discharge graph should be also better)

What do you think ?

Just, I found the graph for Panasonic's here: http://endless-sphere.com/forums/viewtopic.php?f=2&t=59461&start=25 and I didnt find it on any other website... (A fake one?)

Thank you !

 

[Allex]

I use PFs on my BBS02
http://endless-sphere.com/forums/viewtopic.php?f=6&t=67390#p1014574

4p is ok for 25A but they should not be used for anything more than that power.

 

[riba2233]

PF's are more than fine, 25R is overkill. They can endure 10A continuous, but they need some airflow or cooling for that. But 25 A for whole pack is more than ok.

 

[alexis57]

I want more capacity for the same current, then PFs are better. (for a 6.25A)

Orbtronic et panasonic c'est pareil : http://lygte-info.dk/review/batteries2012/Orbtronic%2018650PD%202900mAh%20%28Black%29%20UK.html

Thank you !

I'm sorry for this question, I'm doing a state of the art of batteries and I'm finishing.
I bought 52 Panasonic cells !!
Now I need to find a great BMS.

 

[riba2233]

This one worked great for me.

http://www.ebay.com/itm/Battery-Protection-BMS-PCB-Board-w-Balance-for-13-Packs-48V-Li-ion-Cell-max-25A-/251497839451?pt=LH_DefaultDomain_0&hash=item3a8e707b5b