Renata SA Soldering - Manual

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the swiss power source
46
Soldering
Hand soldering
Never solder directly to the cell surface. Use cells
with tabs only (see related section of our Products
Line). Do not allow the soldering iron to get
directly in contact with the battery body. Do not
apply heat any longer than necessary to achieve a
safe solder connection (max. 350°C
for 5s in the soldering area of the tab).
Wave soldering
During passage of the battery terminals through
the solder wave, the battery is short-circuited. As
this usually takes less than 5 seconds, the loss of
capacity is negligible. Subsequent to a short-
circuit the battery voltage will recover to a value
above 2.5 V almost immediately. Full recovery to
the initial voltage may take hours or even days.
Please note this effect in case electrical
characteristics are measured while the battery
voltage is recovering. The battery may appear to
be defective, but it is not. Temperature at the
battery needs to be controlled below 85°C.
No reflow soldering with batteries
Never use reflow soldering on batteries! Lithium
batteries are not suitable for reflow soldering
processes. The high temperatures required for
this soldering method would deform the gasket,
causing electrolyte leakage, deterioration of the
battery performance and possible rupture or
ignition.
Reflow soldering of SMTU holders
If assembly by reflow soldering is requested, it is
possible is to solder a Renata battery holder of the
SMTU series but place the battery into the holder
after the soldering process. The peak temperature
of the reflow soldering profile is recommended to
not be above 270°C for 40 s (245°C for another
40 s).