Sennheiser batteries are rechargeable lithium ion (LI) batteries.
LI batteries in general don’t store very well.
We run through our batteries very quickly so none of them have time to get old.
You should only purchase them as-needed and plan to use them within a month of purchase.
Their longest shelf life is 12-18 months. But we don’t recommend keeping them past a few months.
Don’t let your batteries die in vain storage! Buy them as-needed and take advantage of our free and fast shipping!