Siemens S45 Service Manual page 18

voltage collapses so much that the mobile phone switches off again. In this case
trickle charging starts again with a now raised threshhold voltage of 3.75V instead
of 3.2V, at maximum for 20 minutes.
• A phone with a fully charged Li-Ion battery cannot be supplied in the standby or
talk modus in the beginning because any input current would cause an
increase in the battery voltage above the maximum permissible value. If,
through using the phone, the battery has been run down to the tune of about
95% (estimated value), it can be supplied with current normally and the battery
can be re-charged.
• The phone cannot be operated without a battery.
• The phone would be destroyed if the battery were wrongly poled:
⇒ design-wise it is impossible to wrongly pole the phone. This is
prevented
⇒ electrically, a correctly poled battery is presumed, i.e. correct poling
must be guaranteed by suitable QA measures at the supplier
• If an unsuitable charger is connected, the mobile phone can be destroyed:
⇒ a charger voltage >15V can destroy resistances or capacitors in the current
supply
⇒ a charger voltage >20V can destroy the switch transistor in the current
supply.
If, in so doing, the transistor fails, then the overvoltage switch-off in the ASIC will
cease to function and the ASIC will be destroyed. Then the battery safety switch
will come into play. In the case of voltages smaller than 15V and an inoperative
current restriction, the battery can be permanently damaged. A protection against
grossly negligent use by the customer (e.g. direct connection of the charge
contact to the electricity supply in a motor car) is not foreseen. Customer safety
will not be affected by this restriction.

A v o i d s h o r t i n g t h e b a t t e r y t e r m i n a l s .
Charging
The battery can be charged when it is inserted into the phone. The charging process is
completely controlled by the mobile. Charging can be done with any of the following accessory:
1. Rapid charger
2. Travel charger
3. Car charger
4. Desktop charger
by
If the temperature is too high or too low, there is a high probability
that the battery is not charged. To enable the charging process again,
battery and phone needs to cools down or warm up. Battery
replacement is not required.
mechanical means.