Charging battery in the round plug

[ComBE]

Hi, we placed a new concorde battery 3 years ago but then the plane went under serious work for 3 years. Now we are having problems keeping the battery running normal. We replaced it with a new battery because not using a battery for 3 years isn't a good plan. (RG-35AXC)

My question is, we tried to charge the battery overnight by putting 12V into the left round piper plug. But in the morning we werent able to start the engines, the guy who I bought the new battery from told me that you cannot charge a battery from the 'external' starter plug. Is this correct ? So the only way is to directly connect the battery on top to charge it ?

If you jumpstart, would you takeoff with an empty battery then ? If no, then we would need to be able to use a system to charge the battery before takeoff ?

thanks

[AlanBreen]

He is correct.

On many installations there is no need to even turn on the Battery Master to get the external plug to power up the aircraft.

Either way, without the battery master switch on and the battery solenoid operated the battery is not connected to the aircraft electrical system. Plugging power into the external socket does not automatically connect to the battery.

For any power to get to the battery from the external power the battery master needs to be on, however you are now powering up the whole electrical system which is a bit pointless just to charge the battery.

If the battery is completely flat there will not be enough energy from the battery to pull in the battery solenoid to start with so there will be no power going to the battery with the external power connected. This is a common problem when the external power is used to start an aircraft with a dead battery. The external power provides power for the start and probably excitation current for the alternator/s which may be able to power the aircraft systems for the flight but at the end of the flight that battery is still dead.

The best way is to charge the battery is to disconnect it and put it on charge.

[SPNA]

[steen]

[AlanBreen]

[Alan Cheak]