how can they be contacted ?not sure ,but anyway i doubt they speak english,and after all ,you wouldn't expect them to admit any fault.no one ever does .!
Theyre unlikely to be any different to any other manufacturer,ie demand outstrips supply ,and quallity control goes out the window.
Anyway ive spoken to the Australian distributor, and he's looking into the matter,I took photos of the bats charging etc ,showing high and varied ir values,they may replace them ,i wait and see.

thebarnfloor.com, I would contact them

I don't know about Aussie distribution but the guys do ship internationally.

I tried ,but don't ship lipos to Aus.
just wondering If anyone "has" tested for IR of 5200 4s packs recently ?and found irregular high readings !
Ive tested with a Hyperion 720 duo ,and a thunder power TP820cd,and both show high ir and poor cell matching ..
Surprisingly however, they dont seem to be far out of ball cell voltage ,at end of a 12.5min run!
I've cycled both packs 5 times before using in the buggy ,and IR improved a little in the good pack (now at @ 12mh),and pack 2 now 14mh.but individual cell ir is not improved ! ie , pack1 (c1 to c4)is 3,2,3,2.mh pack2 is 3,1,5,3.mh.
As i mentioned earlier,both myself,and others localy,have been using these vant 5200 packs all year ,and i havent heard of a legit complaint about them ,and ive been singing theyr'e praises ,not only for great run time punch and all,but mainly because theyr'e so light weight 485gms !,in a MBX7 they ballance the the car perfectly ,compared to simmillar capacity batts .

I'me waiting to hear from the AU supplier as the outcome of my complaint/enquiry,will post any results

To measure internal resistance do the batteries have to be charged, discharged or it doesn't matter?

IR is measured DURING the charge process.

I have the icharger 206b it has a mode in the special modes "measure internal resistance ". This can only be run on its own not while charging. After reading my manual I have noticed I can hold start\enter for 3 sec and check there also.

For measuring IR try to be as consistent as possible, if you want to compare and track pack condition. Same charge state, why many check it at end of charge. Very important to be at the same pack temperature. First charge of the day will likely be slightly different than later charges. Charge rate, etc.

I've never seen anyone track IR that way. For all the reasons Dave lists below.

Excellent. Thank you. So is best to check it say the end of the second charge?

Ok no joy with waranty in aus.I eventualy used the unballanced pack,it failed within a few uses.ie droped a cell.
No more vant for us. Switched to GensAce .no problems.
I have just had a conversation with the retailer in Aus ,and will replace the failed lipo,if i return it.He also told me ,that this was the only vant 4s pack ever returned for warranty!

suggest this lipo for 1/10 touring mod 4.5T 5.5T?
http://www.vantbattery.com/product_show.asp?keyno=1137

Vant batteries advises a 10 gauge wire direct, with their 2s 7600 pack that has the 4 leads. I used a 12 gauge and it got very hot, so I went to a 10 gauge and now it works great! These have plenty of amps for my motor.

So since its illegal to post faulty or damaged lipos, thats that !
Kind of explains why there's never been a claim in Australia lol.
SMC and Hobbyking will replace failed lipos on photo evidence!

That's news to me with SMC. Perhaps it's a new thing but when my SMC Shorty failed I called them up and was offered a replacement for the low price of $10 off. That thing was pretty new, less than 20 cycles. Needless to say I wasn't a happy camper.

I think they give 30 bucks off ,but better than nothing!