What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Starting a Lycoming with a dead battery

Lycosaurus

Well Known Member
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. :eek: 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:D

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.

Lessons learned?

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. :rolleyes:

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.
IMG_1535.jpg



IMG_1537.jpg


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.
IMG_1536.jpg
 
Last edited:
My master was left on and I hooked up jumpers to the alternator/engine side of the master and launched into the dark some years ago. Of course same thing, no juice to open the switch to/from the battery side.

The alternator stayed up with all the electrics until I switched on the landing light on approach to home base.....everything went black, breaker killed the alternator. I practice lights out landings occasionally and stayed with the approach and landed uneventfully. Same lesson learned.

Tie tail down also.
 
been there done that

Nine times out of ten a small whack on the master contactor will be enough to get it to engage with low voltage, so the alternator will come online.
 
Lessons learned?

A lesson I learned after running down a battery trying to start a chilled engine is to not charge a dead battery with the aircraft's alternator. I saw 49 amps being pumped out of the little 35 amp alternator as it desperately tried to recharge the dead battery while still on the ground with little air flowing through the blast tube. Not surprisingly, the overheated diodes in the alternator died soon after.

Best to charge the battery prior to engine start so the alternator won't be tasked with handling a huge load.

On a related note, the Radio Shack audio transducer I wired across the oil pressure light is doing a fine job of reminding me to turn off the master switch. ;)
 
Last edited:
Back when I had my old Grumman Yankee with the BIG engine and LITTLE battery (mounted behind the baggage area), I occasionally had to jump start in visits to the cold country. It was always a pain - dragging cables through the cockpit, drawing huge arcs if you momentarily shorted to ground trying to clamp on with car cables.....I vowed that any airplane I had thereafter would have an external Aux Power hook-up, good enough to plug in a cable and start from a cart. that's how I built the Val, and I never have to be worried about getting stranded with a dead battery! (Have only needed to use it that way twice in 1000 hours, but it's well worth it when working on electronics...)

Paul
 
I always leave my beacon on or if their is no beacon I leave the nav lights on at all times. This gives me an indication that power is still on when walking away from the airplane, and it has saved me more than once!
 
Back when I had my old Grumman Yankee with the BIG engine and LITTLE battery (mounted behind the baggage area), I occasionally had to jump start in visits to the cold country. It was always a pain - dragging cables through the cockpit, drawing huge arcs if you momentarily shorted to ground trying to clamp on with car cables.....I vowed that any airplane I had thereafter would have an external Aux Power hook-up, good enough to plug in a cable and start from a cart. that's how I built the Val, and I never have to be worried about getting stranded with a dead battery! (Have only needed to use it that way twice in 1000 hours, but it's well worth it when working on electronics...)

Paul


any pix and diagram on that?

TIA
 
I always leave my beacon on or if their is no beacon I leave the nav lights on at all times. This gives me an indication that power is still on when walking away from the airplane, and it has saved me more than once!

I will hang my head in shame and admit that once I left the Master on and left the airplane WITH THE EFIS STILL POWERED UP AND GLOWING!! I'm not even sure that a strobe would have helped me ....:eek:

Bob Knuckoll's has drawings and diagrams, and a great "How to" on the Aeroelectric web site.
 
Lesson learned

I grew up hand propping a J-3 Cub and Piper Colts. One month ago had my RV7A panted and went to pick it up (150 miles from home) and the master had been left on. So we put a battery charger on while we went to lunch and returning only to not have enough to turn the 0-360 over. Had never prop a three bladed prop before so was trying to be careful but it got me on a backfire. Cut three finger on my left hand and broke my right arm. Had about 40 stitches in the three fingers and surgery on right arm. I will heal just fine but will never hand prop a three bladed prop or anything over 100HP. Also I am going to install a plug for jump-starting.
Lesson learned the hard way,
Squeak
 
I have the Bob Nuckols style external power plug wired directly to my battery. I beleive that this is a Piper style plug available at AS. It is mounted to the engine mount via adel clamps right beside the oil dipstick tube. It is easily accessed through the oil door (RV-6).

I keep the male plug handy with two leads on it. Plug that in and hook up a battery charger. No de-cowling. Great for working on avionics and It has saved my bacon already once to quickly charge a near dead battery.
 
I did the master switch thing once and was pretty embarrassed about it. I added a standard 110v female socket just inside the oil door, wired to the battery. I carry a short length of drop cord that can be plugged into the socket and attached to a charger or car battery. The ends are marked + and -. It will bring the battery up to something reasonable in less than half an hour with a charger. It saves pulling the cowl and looking even more like the idiot... When jumping with a car, I would stay with the plane to make sure there isn't any overheating of the wire as there isn't any current limiter. A low amp charger is safer in that regard. It has been used, and it works! I now leave the strobes on to HOPEFULLY prevent leaving the master on. That has worked so far.

Squeak, Sorry to hear about your mishap. Can't wait to see the paint job.

Bob Kelly
 
I will hang my head in shame and admit that once I left the Master on and left the airplane WITH THE EFIS STILL POWERED UP AND GLOWING!! I'm not even sure that a strobe would have helped me ....:eek:

Paul, not only was the EFIS glowing when I shut the hangar door, the big 'ol oil pressure light was on (the one that was supposed to keep me from leaving the master on....)!

If the Radio Shack transducer screaming at me doesn't work...........:eek:

I've never been a fan of keyed master switches, but my hangar-mate reminds me about how his RV key is on his car key ring......
 
Another alternative

I recently started carrying a light-weight cigarette lighter "jumper" system: Simple Start

If I should ever be caught with a dead battery, this should allow me to get charge it from any available car or an airplane with a cigarette light socket. I haven't needed it yet but that's the theory. I weighs a lot less than regular jumper cables and I don't have to worry about how to get the large clamps/cable onto my battery.
 
I recently started carrying a light-weight cigarette lighter "jumper" system: Simple Start

If I should ever be caught with a dead battery, this should allow me to get charge it from any available car or an airplane with a cigarette light socket. I haven't needed it yet but that's the theory. I weighs a lot less than regular jumper cables and I don't have to worry about how to get the large clamps/cable onto my battery.

Do a test run with this and a dead battery............ I think you will find that it will take a lot longer than you are willing to wait for your battery to get to the point where it will start your A/C. I did look at the web site, no useful information there. How long do they say it will take before you can start the motor?
 
Cig lighters in cars usually have fuses rated between 5 and 20 amps. Figure they designed the thing not to blow fueses on most cars and it probably doesn't charge at more than 4 amps. That will take quite a long time to re-charge a batter. Even at a charge rate of 20 amps it will take a significant amount of time.

good luck
 
dead batt

I've been guilty of leaving the master on more than once but always got going again. One time however the FBO left master on after some minor maintenance and then kindly came out to jump our Lance. Engine started easily but I didn't turn on alternator switch until after jumper cables were disonnected. Then compounded it by failing to notice there was no charging going on, took off, and then had to land with light signals when batt went totally flat. Lesson learned. Might this be another reason to leave alternator switch on full time? I will wire a lighter socket directly to the battery and hope it will be easy to energize the alternator through this and also trickle charge the battery. Any negatives beside the obvious of leaving some load plugged in and inadvertently draining the battery?
 
If you read Bob Nuckoll's ideas on batteries, he states that "jumping" a battery and immediately going flying is a pretty bad idea. Much better to charge the battery first, then go flying.

If you go flying immediately, you have no battery reserve to power anything with should the alternator fail.

I would never jump a battery and then launch into IMC:eek:
 
... I will wire a lighter socket directly to the battery and hope it will be easy to energize the alternator through this and also trickle charge the battery. Any negatives beside the obvious of leaving some load plugged in and inadvertently draining the battery?
Bill,

I did exactly that. I used 14 AWG wire and a 7.5A breaker wired to the always hot buss. No down side from what I've seen. However, I would suggest you modify a lighter plug so it has staggered pigtails so you can use the charger at any FBO. Stagger the ends to minimize the risk of shorting out the clamps on the charger.

As mentioned earlier, it does take some time to charge your battery with a trickle charger.

My charger came with multiple adapters and one of those allows you to put wires on your batter terminals and a molex connector on the other end. Some builders have put this on their battery and zip-tied the molex connector close to the oil door. Not a bad way to go.
 
I'm with Sam!

A lesson I learned after running down a battery trying to start a chilled engine is to not charge a dead battery with the aircraft's alternator. I saw 49 amps being pumped out of the little 35 amp alternator as it desperately tried to recharge the dead battery while still on the ground with little air flowing through the blast tube. Not surprisingly, the overheated diodes in the alternator died soon after.

Best to charge the battery prior to engine start so the alternator won't be tasked with handling a huge load.

On a related note, the Radio Shack audio transducer I wired across the oil pressure light is doing a fine job of reminding me to turn off the master switch. ;)

Listers,
Sam offers great advice in his post above. Those 35/40 amp super small Nippon Denso alternators are great units and save weight. However, as Sam found out, the rectifier diodes often won't hold up to a full/over rated load charge for more than a matter of seconds. The voltage regulator controls just that, the charging voltage. If the battery's charge is low enough, that can cause the alternator to attempt to charge that battery above it's rated output.
When using one of these units, ALWAYS charge up a flat battery before committing aviation. If you plan on any high draw items in your RV [heated seats or clothing, heated pitot], a 60 amp ND would be a better choice.
Charlie Kuss
 
PS. This is the $30 charger I use. The good news is it is approved for our PC680 batteries:


(click for details)
 
Hand Proping

I wired up the idiot light connections on my alternator. So now like a car it glows if the master is on and it alternator is not running. I have thought of a buzzer as well, but that would be too annoying if working on the electrics. Its saved me a couple of times.

I assume it would begin to glow dimly if the alternator began to fail, as I have seen the lights do in cars.

Joe Hine
RV4 C-FYTQ
 
Battery condition

The Odyssey PC-680 battery was basically left flat for a 12 hour period. After partial recharge on the ground, and a total of 1 hour flight, it would seem that the battery has recovered well.

5 days after the above flight, the battery voltage is measured at 12.97V. That's an indication of a fully charged battery. Tough little battery.

As for capacity, I am presently performing an annual inspection. Will check capacity by applying a timed load and then measuring subsequent residual voltage. Hopefully it will still have enough 'oomph' left to start the engine when at 50% capacity.
 
Last edited:
Back
Top