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**Twins / Re: A65 charging**

« **on:**06 December, 2017, 11:44:14 »

You may have cooked your battery, they do not like being over-charged. (and could cause a fire)

The zener is manufactured to limit the voltage to about 15V-ish.

When the rectified Voltage from the alternator reaches the zener cut-off Voltage, It passes current (Amps) to earth.

It gets hot, hence the heat sink.

This limits the Voltage to the battery.

i.e. say the Voltage output (without zener) is 20V, the zener needs to reduce this Voltage by 5V.

In avalanche mode, the resistance of the diode may be very small. Say 1.0 Ohms.

W (Watts) = E squared (Volts) / R (Ohms) so, 5 x 5 = 25/1.0 = 25 Watts.

W = EI so I = W/E, I = 25W / 8V = 3 1/8 Amps.

The diode plus heatsink must dissipate 25 Watts as heat. It needs a good airflow across it to dissipate this heat.

The zener is manufactured to limit the voltage to about 15V-ish.

When the rectified Voltage from the alternator reaches the zener cut-off Voltage, It passes current (Amps) to earth.

It gets hot, hence the heat sink.

This limits the Voltage to the battery.

i.e. say the Voltage output (without zener) is 20V, the zener needs to reduce this Voltage by 5V.

In avalanche mode, the resistance of the diode may be very small. Say 1.0 Ohms.

W (Watts) = E squared (Volts) / R (Ohms) so, 5 x 5 = 25/1.0 = 25 Watts.

W = EI so I = W/E, I = 25W / 8V = 3 1/8 Amps.

The diode plus heatsink must dissipate 25 Watts as heat. It needs a good airflow across it to dissipate this heat.