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BrianG · 11.28.2011, 11:12 AM

I agree with the replies here.

Also, statistically speaking, the chances of getting a B cell in an A pack are still pretty slim. Sure, it'll happen, but that's the nature of the hobby - just like getting a new ESC that bursts into flames upon first hookup. Besides, most of the time when there is a bad cell, you only know about it a few cycles down the road. How is a manufacturer going to test a cell? It's not like CPUs where they bin them by how fast they can go and be stable; there's really no easy test for lipos (without cycling them) as long as they aren't crap right off the line. The IR and voltage could be within spec, but some other unknown manufacturing/materials flaw could arise later on.

So, a consumer is left with choices; A) pay premium prices for (hopefully) A cells in A packs assuming the price reflects the quality; B) get a pack from whoever and pay for extra "insurance" (worked into the price of course) if they do get the occasional B cell; or C) get the cheaper packs knowing they may get a bad cell once in a while, but the price is low enough that buying again (or removing/replacing a bad cell) isn't a big deal.

From a reseller standpoint; they have a couple choices as well; A) offer a time-derated replacement program for extra cost; or B) cycle each cells about 10 times before assembly to hopefully weed out the bad cells (or bin them as B cells). Option B might only be worth it to hard-core racers due to the extra time/cost - not to mention each cycle just shortens a cells life by that many cycles.

	(#4)
BrianG RC-Monster Admin Offline Posts: 14,609 Join Date: Nov 2005 Location: Des Moines, IA	11.28.2011, 11:12 AM I agree with the replies here. Also, statistically speaking, the chances of getting a B cell in an A pack are still pretty slim. Sure, it'll happen, but that's the nature of the hobby - just like getting a new ESC that bursts into flames upon first hookup. Besides, most of the time when there is a bad cell, you only know about it a few cycles down the road. How is a manufacturer going to test a cell? It's not like CPUs where they bin them by how fast they can go and be stable; there's really no easy test for lipos (without cycling them) as long as they aren't crap right off the line. The IR and voltage could be within spec, but some other unknown manufacturing/materials flaw could arise later on. So, a consumer is left with choices; A) pay premium prices for (hopefully) A cells in A packs assuming the price reflects the quality; B) get a pack from whoever and pay for extra "insurance" (worked into the price of course) if they do get the occasional B cell; or C) get the cheaper packs knowing they may get a bad cell once in a while, but the price is low enough that buying again (or removing/replacing a bad cell) isn't a big deal. From a reseller standpoint; they have a couple choices as well; A) offer a time-derated replacement program for extra cost; or B) cycle each cells about 10 times before assembly to hopefully weed out the bad cells (or bin them as B cells). Option B might only be worth it to hard-core racers due to the extra time/cost - not to mention each cycle just shortens a cells life by that many cycles.