Kirkland Signature KS 9.0 User Manual page 71

The batteries used in these hearing aids should not exceed
1.5 Volts. Please do not use silver-zinc or Li-ion (lithium-ion)
rechargeable batteries as these may cause severe damage to
your hearing aids. The table in chapter 4 explains exactly which
type of battery your particular hearing aids require.
Remove the battery if you are not using your hearing aid for a
long period of time.
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