Is it safe to store batteries together?
However, storing batteries close together without a barrier could pose a safety issue. So, it's best to skip this trend regarding batteries unless you use a battery organizer that gives them room to breathe. Otherwise, experts recommend leaving them in their original packaging.
Is it OK to mix batteries?
Don't mix battery chemistries.
Carbon-zinc, alkaline, lithium, silver-oxide and the other battery chemistry types don't get along. Using batteries of different chemistries to power a product can cause damage to your device from electrolyte leakage and over-discharge of the lower capacity batteries.
Is it safe to tape batteries together?
Tape your terminals
If battery terminals touch, they can spark and catch fire. To prevent this, tape the terminals of used batteries. Always use clear sticky tape. Different batteries have terminals in different places.
Is it okay to mix old batteries with new ones?
The performance of a battery-operated product is limited by the weakest of all the batteries in the device. One old or weak battery can cause poor product performance, even if all the others are new or fully charged.