Rainbow Electronics GM862-GPS - Manual (Page 32)

GM862-GPS Hardware User Guide
1vv0300728 Rev. 8 - 20/09/07
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 32 of 73
Last but not least, in some applications it is highly desired that the charging process restarts when the
battery is discharged and its voltage drops below a certain threshold, GM862-GPS internal charger
does it.
As you can see, the charging process is not a trivial task to be done; moreover all these operations
should start only if battery temperature is inside a charging range, usually 5°C - 45°C.
The GM862-GPS measures the temperature of its internal component, in order to satisfy this last
requirement, it's not exactly the same as the battery temperature but in common application the two
temperature should not differ too much and the charging temperature range should be guaranteed.
NOTE: When starting the charger from Module powered off the startup will be in CFUN4; to activate the normal
mode a command AT#CFUN=1 has to be provided.
NOTE: For all the threshold voltages, inside the GM862-GPS all threshold are fixed in order to maximize Li-Ion
battery performances and do not need to be changed.
NOTE: In this application the battery charger input current must be limited to less than 400mA. This can be done by
using a current limited wall adapter as the power source.
NOTE: When starting the charger from Module powered off the startup will be in CFUN4; to activate the
normal mode a command AT+CFUN=1 has to be provided. This is also possible using the POWER ON.
There is also the possibility to activate the normal mode using the
ON_OFF* signal.
In this case, when HW powering off the module with the same line (ON_OFF*) and having the charger still
connected, the module will go back to CFUN4.