Is headway and thundersky the same thing? Now I'm confused. I was refering to thundersky having some problems years ago, with another chemistry, but the real issue was that at the time, they were weaseling on the warantee. I really should shut up though since I have no real info on their current products first hand. I do have first hand experience with ping, and his product, and support of it in the very few cases where there was a problem has been exemplary. Many others have sold some pretty crappy duct tape wrapped product so most of what you say has merit. It just doesn't apply to the cells ping uses, that is all.
I know that 4 ping packs is not the solution that you are looking for, but I did want to point out that it was possible, even though it is pretty far from the best solution for a 120 amp continuous discharge pack. Pardon me also for forgetting that you aussies are stuck with a really crappy exchange rate these days. 4 packs from ping for you would cost almost twice what it would for me.
This whole c rating thing gets confusing, and I am not entirely sure I really understand it, but here is what I belive I know. On the ping packs, with a 20 amp hour pack, the 1 c rate would be a 20 amps, on a 10 ah pack 10 amps, and so on. Makes it handy for calculating. Ping's cells are said to be able to stand 3c discharge, which is why his bms will allow no rate above 60 amps on a 20 ah pack.
But here is where I start to balk, who says this cell can stand 3c continuous? Nobody as far as I can tell. This 3c rate is for a short burst, not all day. The only test data given is for a 1c discharge rate, so as far as I am concerned this is a 1 c cell untill you prove to me it can take more. Others on the forum have told me they are having no problems with 1.5 c rate , so I can belive that a 30 amp continuous discharge on a 20 ah ping pack might be something that works in the real world. So 30 amps into 120 gets you the idea to use 4 packs to get 120 amp continuous. If on the other hand, you need 120 amp spikes and 60 amps continuous, then two ping packs in paralell would do it. Now it only costs 2 times too much, instead of 4 times too much money.
What you are stuck with though, is the only way for you to find out about these great looking batteries in the plastic case is to buy one, and start testing. If you are lucky, someone has, but aparently not so far. I'm sorry if I pissed you off, but I got peeved when the duct tape batteries got commented on. Mine has been absolutely fabulous. But beware of ALL lifepo4 sellers claims. All I have read so far seems to show only A123 has proven high discharge rate capability. PSI and headway cells are still in the testing by forum members in the real world stage in my opinion. The price of the plastic case batteries we are discussing here would indicate to me that inside, you would find some kind of cell that is good for 2 or 3 c. I just can't believe in 10 c cells for that price. I can believe in inflated claims of c rates. If I were you, I'd be real temped to try em, especially if they are local, so you don't get screwed in the exchange rate, and then use em at 2 c continuous or less. I'll shut up now.
I was more concerened about the max voltage being over what my controller is rated for...
