Flew for family Thanksgiving dinner to a town only 1/2 hour flight from home (normally takes us 2:20 hrs to get there by car). Shut down engine, magnetos off, turn off electrical switches .... forget to turn off master!
Ok, so you know where this post is going ....
Next day found a dead battery.
Should not be too much of a problem, since I have magnetos and can start the engine by hand propping. Took a while until I figured out the right amount of throttle primes (... you see, the electric prime system and electric fuel pump were obviously not operational), throttle position etc. Kept a fire extinguisher nearby ... finally fired up the engine. Woohoo
Hmmm.... electricals are still dead, no voltage.... of course! No voltage for the alternator
field, therefore the battery will not be charging. Had to remove the top cowl and use booster cables (another trip to the airport, since we did not have any on-hand). There's not much to grab onto the battery post of the Odyssey battery with those big booster clips. Managed to clip it on, and not short to ground around it. Let the car idle for about 20 minutes so the battery would hold some sort of charge.
Removed booster cables, cowled it all up, and hand propped it again (wasn't sure I had enough charge in the battery for an electric start). Engine starts and battery is being charged at ...> 50 amps by the PlanePower alternator
. This at idle speed. Let it charge for a little while on the ground, testing electrical operation such as flaps etc., then went for a 20 minute flight around the patch until charge current came down to a close to normal level.
Later that afternoon, was able to start the engine normally, and fly back home.
On shutdown, now I plan to just turn off the magneto key switch and master switch (one after the other). I will position the other switches as necessary before next engine start. Yeah, a checklist for that portion of the shutdown could be useful as well.
I have a 12V socket fused at 20 amps in the cockpit. I'll make a "slow" (may need a high wattage series resistor to limit current) booster cable set so I can quickly charge the battery from a nearby vehicle. This will be safer than the car booster cable, and I will not have to remove the top cowl. Not that I plan for this to happen again.
Even though we have mags, a dead battery means you won't be able to fly out after just hand propping the engine, since the battery won't recharge on its own. I have passive instruments for backup (steam gauges and such), however engine and fuel monitoring equipment would be inop.
P.S. In our case, the airplane was tied-down when hand propping the engine.
Battery being charged. Moved the truck away before hand propping the engine.
In the photo below, you can see that there is not much to grab on to. Easy to short the cable to ground ... could have used some insulator like duct tape. Connected the Positive lead first, then once I was assured it was solid, connected the ground and left it alone to charge over a good 20 minutes to 1/2 hour. I plan to make some sort of booster connector attached to the battery post so this will be a little safer to do.