Switchable Keep Alive

[skysailor]

I am concerned about keeping the internal batteries charged in the D180 I plan to install in the aircraft I am building. I know the current advice is to leave out the Keep Alive wire due to problems I have read here. Does the Keep Alive circuit charge the internal battery? If so, if it were switched such that Keep Alive is only powered when the aircraft is in the hangar, would there be any detrimental effects on the D180? The obvious and certainly more fun way to charge the battery is to fly but I need to be confident the backup battery will function even if the plane has not flown in a week or two. I keep my present aircraft on a battery conditioner while in the hangar to keep the main battery in the best condition. I am reluctant to leave the D180 powered up for the entire time the plane is parked as there is no air circulation and at some point the screen will "burn in".

 

[dynonsupport]

The keep alive circuit does charge and keep the internal battery charged. You are welcome to hook up keep alive if you really want to.

The internal battery, when charged, lasts well over a year in an EFIS. The only load on it is the clock in the EFIS, not all the little, random loads in a plane that the main battery needs to deal with. So if you go flying once every 4 weeks, the battery is only down about 10% and would still give you well over an hour of backup time.

We don't even start re-charging the battery until it's down 10%, so if you fly every 2 weeks, chances are that keep alive won't even get used.