Peter Donofrio:
Am I allowed to replace the battery in my ’76 Sundowner myself, and if
yes, what should I watch out for?
Willis Cooke:
Yes, you are allowed.
Some would say that you need instruction and sign off from an A&P.
Be sure that you take the negative lead off first and put it back last to
avoid major arcs that will happen if your wrench connects the positive post
to the battery box while the negative lead is connected.
Check that the vent and drain hoses are in good condition and connected.
Check that the battery box is not corroded or that you have cleaned,
repaired and painted it with acid proof paint.
Be sure that the charging system is working and putting out 13.8 to 14.0
volts when the engine is running.
Be sure the cable ends are clean. Clean them if they are not and paint
them with corrosion protective paint.
Be sure that the new battery is full of water if it is not sealed.
Be sure that the hold down pads in the battery box are good and that the
battery is securely held when the box is closed.
If you can do all that in 15 minutes you might have the making of an A&P
so that you can get right making $12 or so an hour.
Editor’s Note-
Be sure that the battery has been fully charged prior to installation. You should not perform high-current charging with the battery in the plane. You also should not subject the charging system to the high loads created by the aircraft’s electrical demands, along with restoring a partially drained battery. Normal recharging (after a start) only takes a few minutes, but a low battery will take much longer to “get full”.