User's Manual

Page 16 of 83

A Carrier Corp. Company

PART NUMBER T82002163

REV A

• Fully discharged cells are automatically trickle charged at 10% of the programmed current until

the cell voltage exceeds 2.5V/cell.

• Charging terminates if the low-battery condition persists for more than 25% of the total charge

time.

• The LTC4006 includes a thermistor sensor input that suspends charging if an unsafe temperature

condition is detected and automatically resumes charging when the battery temperature returns to

within safe limits.

• The LTC4006 charges a 7.4VDC/6A battery pack.

• The battery pack contains 6 Li-ION cells (2S3P topology).

• The battery pack internally contains a Li-ION protection circuit.

Design Note:

Note during prototype testing, we supplied 15VDC input to the TSII and the L105 inductor on the

LTC4006 Charger Circuit reaches approximately 60-62C during charging (in open air). We will look

into adding a passive heat sink to dissipate some of the heat. This was also the case when we supplied

24VDC input to the TSII.

After charge is complete, the L105 inductor will reach 29-30 degrees C (in open air). An NTC

Thermistor was used to measure the temperature of the L105 inductor.

3. LM339 Low Power Low Offset Voltage Quad Comparator. (Low-battery detection):

• The circuit is comprised of two Compartors. If the Vin(+) terminal is Low and the Vin(-) terminal

is High, then the output is Low (current will flow). However if the Vin(+) terminal is High and the

Vin(-) terminal is Low, then the output is High (current will not flow).

Therefore, If the Load in the variable input (5 – 27VDC) is <= 6.5VDC, then the Low Batt LED will be

ON. However, if the variable input is >6.8VDC, then the Low Batt LED is OFF. The other input VB =

3.3VDC, which is a fixed voltage input.

4. Battery Pack Protection Circuit (model: 033A-BXA)

• Function: Over charge detection, Over discharge detection, Over current detection, Short

detection.

• ELECTRIC CHARACTERISTICS (@ 25C)

1) Over charge detection voltage: 8.5V +/- 50mV

2) Over charge release voltage: 8.1V +/- 100mV

3) Over discharge detection voltage: 4.8V +/- 160mV

4) Over current detection: 4.00A ~ 7.00A

5) Over charge detection delay time: 0.55S~2.06S

6) Over discharge detection delay time: 67~141ms

7) Over current detection delay time: 6.3~14.7ms

8) Consumption current

– Operating mode : Max 14.2 µA

– Power - saving mode : Max0.2µA.