I didn't fly for a few months, when testing my lipos seem to have died?
I got 2x 2200 15C-rated 3cell packs, never discharged under 9V (under load) , always used a balancer etc etc. The max discharge is about 12 Amps static (well below 15C).

Before I put them away I charged the pack about 50% and it has self-discharged next-to-nothing over this time. Before testing I charged the batteries ofcoarse.

Problem I got is that under the slightest load, the voltage drops to about 9.5 V (and esc cuts off), In short, they can't handle any current anymore. both packs behave the same.

What did I do wrong? Any remedy for recovery ? These batteries have only about 10 cycles on them.

Thanks in advance,
GJ

hrm, sounds like you did everything about right.

What was the voltage you ended up storing them at, and what voltage were they at when you got back to them?

The thing you can do is try reforming them. That means a 0.5C charge and a 2C discharge for 3 to 5 cycles and see what that does. Maybe that would wake them up. Other than that I couldn't really guess what happened to them unless they were cheap packs or got too hot.

hopefully that helps =)