Nikon SB-400 Manuel D'utilisation page 6

Preparation
11 Keep small accessories out of the reach of children to avoid the possibility
of the accessory being swallowed. If an accessory is accidentally swallowed,
immediately consult with a doctor.
12 Use only the batteries specified in this instruction manual.
En
Batteries other than those specified could leak corrosive liquids, explode or catch
on fire or otherwise not perform satisfactorily.
13 Do not mix battery types, brands or old and new batteries, as the batteries
could leak corrosive liquids, explode or catch on fire.
When using more than one battery in a product, always use identical batteries
that were purchased at the same time.
14 Non-rechargeable batteries such as manganese, alkalinemanganese and
lithium batteries should never be charged in a battery charger because
they could leak corrosive liquids, explode or catch on fire.
15 When using standard size (AA, AAA, C, D) or other common rechargeable
batteries such as NiCd and Ni-MH battery types, or when recharging
them, be sure to use only the battery charger specified by the battery
maker and read the instructions thoroughly. Do not recharge these
batteries with their terminals reversed in the charger or before the
batteries have cooled off sufficiently because they could leak corrosive
liquids, explode or catch on fire. The same caution also applies to using the
rechargeable batteries that may be supplied by the photo product's
manufacturer.
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