Icom A4 battery dead?

[gertcoetzee]

I have an Icom A4, and the past weekend it just went dead. I have left it with the power supply on, and would have thought it had charged.

When I plug the power supply in, with battery attached, it is dead.
When I take the battery off, and plug the power supply in, it works.

When I tested the battery it had 1.2V. Leaving it plugged in does not increase the V.

So I thought I have nothing to loose by attaching the battery (without radio) to a (yes I know, should not - car - ) battery charger, and after a second or two checked the battery again and now the V is up, and connecting it to the radio it now works, but the sign to charge appears on screen.

Why would the battery charge with the battery charger, and not with the power unit?

Disclaimer : know nothing about electricity, can use a defibrillator and change a light bulb (under duress).

[mulderpm]

Your Icom A4 has a Li-Ion battery pack containing two cells each delivering 3.6 volts (7.2 V pack). The charger is a special Li-Ion charger designed to deliver a constant current and constant voltage, specific to the rating of the battery pack that needs to be charged. The charger charges the pack with a constant current until the voltage per cell reaches 4.2 Volts and then continues to charge with a constant voltage (4.2 V) untill the current drops to zero. The battery pack also has an electronic safety circuit built into it, which checks temperature (safety fuse) and over voltage/charging. The reson for this circuit is that if a Li-Ion pack is overcharged or short circuited it can explode. If the cell voltage drops below 2 volts the safety circuit opens up and the batter can no longer be charged....with the dedicated charger.

What you managed to do is to get the safety circuit the close again and thus charge the battery..albeit with the wrong charger.

The battery is actually finished and I would not trust it. Rather replace it. There are a couple of places in Pretoria and the East Rand that can do that for you for a fraction of the cost of the original Icom pack. (R 150).

Oh....One last thing. To extend the life of a Li-Ion battery you should store it at 40% charge and at a low temperature, but not below 0 deg Celcius, and never discharge it fully.

Hope that helped.

[gertcoetzee]

Thanks for the reply.

Would like to buy a replacement....which places in Pta/East Rand?

[ZULU1]

Gert and others, the Icom ICA4 is the same radio as the Icom ICF3 which was a very common security guards radio. They are available from Radio Communications warehouse in Cape Town. Ask for the ICF3 1100mah Nimh battery as thats the most common unit. The ICA4 looks identical. Southern suburbs somewhere.

[mulderpm]

Thanks for the reply.

Would like to buy a replacement....which places in Pta/East Rand?

Gert, in Pretoria I go to S & P Power Units, 012 335 5734 or in Benoni, Specialised Battery Systems, 011 425 3447. In Cape Town you can try International Power Products (IPP) 012 551 4141.