To the question "Trickle charge current is also mentioned on the spec sheet as being 100ma, not enough to kill a 400ma cell."
If you read the datasheet fully, you find this lines:
#Low Battery voltage VBAT When Battery voltage lower than VBAT £¬the Boost will be shutdown 2.78 2.85 2.92 V
So in between 2.78 and 2.92V (tolerances) the device will stop operating)
#Trickle charge current ITRKL VIN=5V£¬BAT=2.7V 100 mA
#Trickle charge stop voltage VTRKL 3 V
In between 2.7V and 3V (i assume +/- tolerances) the device will Trickle Charge with lower current not to stress the battery at low charge.
So it is not charge keeping tricke charge, but stress reduction .
I assume (not written in datasheet) that below 2.7V of the battery no charging will start (under voltage shut off to prevent safety risk). There is the risk of a burning LiPo battery if a undervoltage battery is charged again. So leaving the device for a long time with 50?A discharge will destroy the battery.
#Target charge voltage VTRGT 4.2 V
#Recharge threshold VRCH 4.1 V
Charging is done up to 4.2V (switch off) and charging starts again with 4.1V (restart)
vy73 de Karsten, DD1KT
