Working with the demonstration board

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To properly connect the battery to the slot, It is good practice to start by soldering a

particular slot to this connector and then connect the battery to this slot. You can connect

the battery directly to the connector, but note that improper connection can affect the

accuracy of the analog measurement, which in turn can affect the overall accuracy of the

charge.

The battery terminals are connected to pins 1 and 3. One end of the NTC is connected to

pin 2, while the other end is connected to ground (Figure 8). Additionally, the NTC is placed

close to the battery so as to have an accurate temperature reading of the battery.

4.3

Monitoring the battery charging status

The demonstration board has two LEDs: D8 and D9. The functions of these LEDs are

explained in Table 1 and show the charging status.

Note:

A charging error occurs when:

●

there is a hot or cold condition

●

there is a short-circuit condition

●

the impedance of the battery is very low.

Note:

When the impedance of the battery is very high, the current ceases to flow through the

battery. In this case, charging is stopped and the status LED shows "charging done" (case 3

in Table 1).

Figure 8.

NiMH battery and NTC connection to the 3-pin connector

Table 1.

Charging status LEDs

Case

Charging status

Red LED (D8)

Green LED (D9)

1

Battery not present/idle

OFF

OFF

2

Charging ongoing

ON

OFF

3

Charging done

OFF

ON

4

Charging error

ON

ON