Truerc 8Ah Lipos?

[BrianG]

I was looking at getting the pack on this page (last pack at the bottom). It says it is a 5s2p pack good for 80A cont, 120A peak. I imagine they are made from the 4Ah 10C cells. If I look at the cell specs, it says they are rated for 5C continuous. That is only 40A for a 2p pack. Am I reading this wrong? If not, is that why the 5s2p pack is so cheap at $165?

[squeeforever]

If the cells are 5C cells then a 2P pack would be 10C. If 5C is 40 amps cont. then 10C will be 80. The packs are really cheap but really good. The owner is a GREAT guy to.

[BrianG]

Sorry, I guess I didn't explain that well. Each cell is 5C 4Ah according to the cell specs. That's 20A continuous. At 2p, that's 40A continuous for both cells together. So, the 5s2p pack is 40A continuous. Or maybe I'm not seeing it right...

[coolhandcountry]

Originally Posted by squeeforever

If the cells are 5C cells then a 2P pack would be 10C. If 5C is 40 amps cont. then 10C will be 80. The packs are really cheap but really good. The owner is a GREAT guy to.

The c rating don't change when you parrellal the cells. It has a higher amp draw for it has more mah.

[squeeforever]

Are not the C rating and the mah somehow correlating?? If the mah doubles the C rating will... That is why you can charge a 4000mah pack at 1C (4 amps) and a 8000mah pack of the same cells at 8 amps.

Brian, I understand what your saying. I did some more figuring last night and it just didn't work out. I'm not sure but if I remember correctly, there 4000mah packs are 40 amps cont.

EDIT: I just looked at it again, and the 4000mah cells are good for 40 amps cont. but where you linked, says 5C, which isn't write. I think I know why. A while back be was using other cells rated for less amps. Maybe he didn't change that on the site?? Just a thought. But the cells are 40 amps cont...

[squeeforever]

I found the specs to the old cells. Maby this helps with the 5C mistery?

Cell Size(milimeters) : 5.0(T)×44.0(W)×140.0(L) ( pack Thickness 30 mm)
Weight: 17.7 oz / 504g (pack weight less wire)
Capacity: 8000 mAh
Voltage : 11.1V
Max Charge Rate: 1C (8A)
Max Burst Discharge Rate: 10C
Safely discharge at 40A up to 48A , with Max burst of 80A (10-15 sec)

[coolhandcountry]

Originally Posted by squee forever

Are not the C rating and the mah somehow correlating?? If the mah doubles the C rating will... That is why you can charge a 4000mah pack at 1C (4 amps) and a 8000mah pack of the same cells at 8 amps

The c rate does not double. The amps draw may double. I think i got what you saying but the way you saying it maybe confusing to others. 4000 mah at 10c and 8000 mah at 10c are still the same c rating but have a higher amp draw for the mah is more.

[MetalMan]

The specs linked to are just what squeeforever guessed. They are the older cells. No worries now :).

[BrianG]

Ahh, thank you Squee and MM! I was just doing all the research I can before I decide to buy them. I still think $165 is a REALLY good price for that pack, especially at 8Ah! The truerc.com owner should really update that spec - it might confuse some people (like it did me).

On a side note, I saw a thread where someone posted a link to the "Lipo Sack". I plan to charge my batteries in my basement where my RC stuff is. Is this Lipo Sack a good idea to use when charging in a house? I think the family will be a little miffed if my hobby makes us homeless from a house fire! :dft002: :p

[MetalMan]

The Lipo Sack wouldn't be too bad of an idea. It certainly wouldn't hurt!

[BrianG]

Originally Posted by MetalMan

The Lipo Sack wouldn't be too bad of an idea. It certainly wouldn't hurt!

Then I shall get one! After all, the price of that pack is so cheap that I can't afford not to get one. :)

[jhautz]

I have and use the LipoSack as well. Simple lightweight solution. If you have room and a kind of permenant place you will be doing your charging of Lipos, here is a link to antoher solution. Not as portable, but seems like it would be more protective than the sack.

http://www.b-p-p.com/proddetail.php?prod=1_BB

[BrianG]

Wow, the large one can double as a bomb shelter. :)

I think for portability, I'll go with the sack. Thanks!

[squeeforever]

Got a link to the sack??

[MetalMan]

http://liposack.com/