Can you jump a 12V plane battery with a car?

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MountainDude

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MountainDude
If you get stranded somewhere with a dead battery, can you jump it with a car?
This is a 1976 C182 with the 12V system.
 
Yes, if you have an external power plug there are even adapters for jumper cables. At least Pipers have them, I am not sure what Cessna has.
 
Absolutely. I had a Cessna land at the airport not long ago and I used a fueling cart that we have that has a 12v deep cycle battery on board.

The pilot obviously knew he had a problem because he had his jumper cables (no power plug) in the back of the plane ... ;)
 
cowman said:
Yes, if you have an external power plug there are even adapters for jumper cables. At least Pipers have them, I am not sure what Cessna has.
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Oh, that is interesting. Yes, I have an external outlet, but never heard of a plug adapter for jumper cables. Will look. Thank you.
 
Daleandee said:
Absolutely. I had a Cessna land at the airport not long ago and I used a fueling cart that we have that has a 12v deep cycle battery on board.

The pilot obviously knew he had a problem because he had his jumper cables (no power plug) in the back of the plane ... ;)
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Thank you. Did you just connect it to the battery leads and started the plane?
 
MountainDude said:
Thank you. Did you just connect it to the battery leads and started the plane?
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That's exactly what you can do.

You can also use a car jump pack. And I've even seen a 24V plane jumped with two vehicles with the batteries disconnected from the cars and wired in series.
 
Yes, but in my experience AAA will refuse to dispatch assistance with such matters.
 
You can, but it is not a good idea unless you know exactly why your battery is dead like the forgotten master switch or a loose connection. Your dead battery might be the result of a tired generator/alternator not producing enough output for all consumers.
 
:yeahthat:
Or improperly set regulator, old cables, etc. A guy with a PA28 asked me for a jump but still couldn't get it started. "It's like this every winter, and I just replaced the battery!" Things that make you go hmm...
 
aggiepack said:
You can, but it is not a good idea unless you know exactly why your battery is dead like the forgotten master switch or a loose connection. Your dead battery might be the result of a tired generator/alternator not producing enough output for all consumers.
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i agree, a battery dead after a period of disuse makes sense. But after flying for a couple of hours, I would expect the battery to be recharged enough to start the plane.
 
Sure, if you are willing to accept the risk of damage to your car’s electrical system. I don’t jump anything off my vehicles.
 
Depending on the quality and length of your jumper cables, this might be more difficult than you think.
What works a lot better is a Li-ion jumpstarter pack. Lighter than a quality set of jumper cables and able to deliver a good amount of cranking amps. No need for a vehicle.
I've used a Noco GB20 a couple times when my battery decided yo go on strike (one cell went high resistance). Jumper cables couldn't do it.
 
My buddy and I jumped into his arrow Fri night and it wouldn't start from a low battery. It does not get flown enough since he gone working/flying so much.
No we didn't use jumper cables.
I volunteer to try to hand prop his brand new propeller. No fricken way with bare hands as it has some pretty sharp edges. It would have been my first time hand propping since my Cox .049 days. lol

We called AAA...

Joking. Pushed it back into his hangar and he took out the rear panel to get to it. It had a Battery Minder charger lead wired into the battery box. 11.6 volts at the battery master off. I used small jumpers to hook up his auto based 12v charger. Got up to 14.0v
Let it charge over night and he flew it around the pattern for a bit yesterday morning. Said it still grunted when he started it. Last night I checked it and it was down to 11.4 with just the master on, 11.0 with pito heat on.

So I just ordered a new concord battery that'll I'll install for him this week while he is gone working. It get's shipped to my place since he is never home. I am only the laborer and happy to do it.
He has his 50 year AP friend that he has known since he was a kid that he talks to everyday. He decides what battery and everything else. He is in Cleveland Oh now but is retiring this summer and moving his tools to my buddy's hangar next door. And he will live closer also. So we both are looking forward to that!

Can't recommend hand propping ...
 
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I used to jump my plane when the battery was going. Used regular jumper cables and tied the cowling down with a rope so it wouldn’t flap around when the engine started. Didn’t try to detach while it was running, just got it hot and ran it for five minutes or so, and then shut down, buttoned everything up, got the truck out of the way, then started up. Worked like a charm!
 
Clip4 said:
Sure, if you are willing to accept the risk of damage to your car’s electrical system. I don’t jump anything off my vehicles.
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I have jumpstarted vehicles, tractors, and the occasional airplane hundreds of times. Never damaged anything.
Gary Ward said:
I volunteer to try to hand prop his brand new propeller. No fricken way with bare hands as it has some pretty sharp edges. It would have been my first time hand propping since my Cox .049 days. lol
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Hand propping is a really bad idea if you've never done it before. But if you know what you're doing, it's usually the easiest and best way to start a plane with a dead battery, as long as an unsuccessful start attempt hasn't left the starter pinion engaged. Though if the battery is completely dead, the alternator may not come on line. It can be awkward on a nosedragger, though.

The small jumpstarter battery packs work well, too, if you have a place to attach it. On my plane the master relay is easily accessible inside the cockpit and provides a convenient place to clip the cables to.
 
I've jumped my plane with regular jumper cables. It does take two people. The battery is inside the baggage compartment (behind the wing). You take the cover off and jump it like a car. After it starts, put the cover back on, close the baggage door and back away.

The one thing to note about many APU plugs is that they often connect AFTER the battery contactor. I your battery is completely flat, you'll get the plane started, but the battery won't be connected and hence won't charge.
 
Justin M said:
Our club 182 has the jumper cables with an adapter on the side of the front cowling. When I plug in the jump box, I can hear the gyro spinning up.
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On my 1980 N 172 the power plug is to power your main buss and does not provide amps directly to the battery to help "jump" start it.
Since all my electric stuff is under my cowl with no access door, I feel it would be impossible to jump start it with cables?
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MountainDude said:
If you get stranded somewhere with a dead battery, can you jump it with a car?
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To add to the above:

1) Be sure to make an effort to know the reason for the dead/low battery. If it is unexpected, take the time to look over the electrical system to make sure there is no obvious fault. Adding a fresh inrush of current to a simple fault can lead to a greater fault.
2) If your aircraft is not set up to accept an external power plug (EPU), then install one if you want this capability. Jumping direct to the aircraft battery is not the preferred method and can cause other issues with some systems.
3) If your aircraft does have an EPU plug verify it is wired to provide start assist. Also keep in mind if your battery is completely dead it may not have enough left to pull the master relay closed once started unless the aircraft system is wired to accomplish this via the EPU voltage.
4) Its best to remove the battery from the vehicle to jump the aircraft. Not only will this keep the vehicle away from the aircraft but also reduce the chance of the vehicle hitting the aircraft as it pulls away. Trust me.
5) Do not even think about a jump if you need to remove the engine cowling to access the battery.
6) And with the availability of reasonably priced jump packs for vehicles, better option is to buy one for your truck and plane and make/purchase adapter to plug into the aircraft EPU plug.
 
Bell206 said:
To add to the above:
4) Its best to remove the battery from the vehicle to jump the aircraft. Not only will this keep the vehicle away from the aircraft but also reduce the chance of the vehicle hitting the aircraft as it pulls away. Trust me.
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Good advice.

Once I was jump starting my Sky Arrow from my Honda Element. Did not use my Engine Start checklist (rare for me), so I did not remember to set the parking brake.

On engine start, plane started rolling forward. Reflexively pushing on the toe brakes did nothing - my plane doesn't have toe brakes. I got to the finger brakes just in time to avoid contact with my car. Whew!

At the very least be very, very careful when jumping a plane from a car - seems straightforward but lots can go wrong.
 
Bell206 said:
To add to the above:

1) Be sure to make an effort to know the reason for the dead/low battery. If it is unexpected, take the time to look over the electrical system to make sure there is no obvious fault. Adding a fresh inrush of current to a simple fault can lead to a greater fault.
2) If your aircraft is not set up to accept an external power plug (EPU), then install one if you want this capability. Jumping direct to the aircraft battery is not the preferred method and can cause other issues with some systems.
3) If your aircraft does have an EPU plug verify it is wired to provide start assist. Also keep in mind if your battery is completely dead it may not have enough left to pull the master relay closed once started unless the aircraft system is wired to accomplish this via the EPU voltage.
4) Its best to remove the battery from the vehicle to jump the aircraft. Not only will this keep the vehicle away from the aircraft but also reduce the chance of the vehicle hitting the aircraft as it pulls away. Trust me.
5) Do not even think about a jump if you need to remove the engine cowling to access the battery.
6) And with the availability of reasonably priced jump packs for vehicles, better option is to buy one for your truck and plane and make/purchase adapter to plug into the aircraft EPU plug.
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Thank you.
My understanding is that if you start the plane via the external APU plug (which I have), but the battery is dead, the alternator may not charge the battery, because some battery power is required to flip a switch that connects the battery and the alternator. If this is the case, it would be better to jump the battery, correct?
 
MountainDude said:
If this is the case, it would be better to jump the battery, correct?
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Not really. Some aircraft are wired in a manner that even with a dead battery, the EPU connection will power the battery relay/contactor and get system working and charging. Look in your POH Chapter 7 or check a wire diagram to see how yours is wired. If not wired that way its relatively easy to add that capability as a minor alt.
 
Have used the lithium battery jump packs. $120 on Amazon. 182 battery is right behind the baggage panel. Hooked up directly to the battery terminals. I started the the plane, buddy who is an A&P disconnected the pack, shut the baggage door, and I was on my way.

It was a 5 year old battery that sat out in cold weather for 2 nights.
 
Our cables are long enough that the car remains behind the wing and the propeller and wing will not hit the car if it rolls forward.

I also chock the pilot-side main before jump-starting.
 
So, I don't know how Cessnas are set up(consult your POH) but on both Pipers I've owned when you apply power to the external power plug a relay clicks and your airplane is entirely powered from whatever that plug is connected to. As in even with the master off, everything turns on and you can crank the starter. Most of the plane's electrical system is bypassed including the battery and alternator/charging system. You can(and the POH supports this) turn on the master for "additional cranking power if needed". As long as one doesn't make any mistakes... like say connecting the battery backwards or putting 24v into a 12v system I'm not sure what the risk is. People jump start cars all the time without issue.

The bigger danger IMO is the ground ops around this depending on where your power plug is. On my Lance the external power is on the pilot's side behind the engine... basically meaning the person outside the plane has to be standing inbetween the spinning prop and wing to unplug after the engine starts. Makes me uncomfortable, and last time I had to have it done I pointed it out to the line guy and asked if he was comfortable with that. His response was that there are far worse setups on different aircraft they deal with all the time and he wasn't worried about it. I'd still want to drill into anyone helping me with such a thing to hug the wing until clear of the aircraft(or some other safe method of egress).
 
not ashamed to admit picking airplanes based on 12V electrical system for AOG considerations. I did make use of that allowance twice in the 13 years I was active in the ownership thing. Finding a 24V source would have been an unwanted overnight.
 
cowman said:
So, I don't know how Cessnas are set up(consult your POH) but on both Pipers I've owned when you apply power to the external power plug a relay clicks and your airplane is entirely powered from whatever that plug is connected to. As in even with the master off, everything turns on and you can crank the starter.
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That is how the 182 is set up as well. When I plug into the port on the side, there’s an audible click, the voltage indicates, the gyro spins.
cowman said:
The bigger danger IMO is the ground ops around this depending on where your power plug is. On my Lance the external power is on the pilot's side behind the engine... basically meaning the person outside the plane has to be standing inbetween the spinning prop and wing to unplug after the engine starts.
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Snip
cowman said:
I'd still want to drill into anyone helping me with such a thing to hug the wing until clear of the aircraft(or some other safe method of egress).
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Yeah so if I ever have help, I ask the helper to stand on the brakes once the plane is started while I disconnect cables and move the vehicle away. I instruct them how to pull the mixture in case of an emergency.

Once I had an FBO help me, but other than that, I don’t put anyone else at risk if I can avoid it.
 
On Mooneys the click is the aux power relay which connects to the battery which of course is unconnected till the master is switched on.
So for me I would charge the battery for 30-45 minutes, then disconnect and then start the engine.
Also, there’s the new lithium powered starter batteries that you can use, no car needed.
 
Clip4 said:
Sure, if you are willing to accept the risk of damage to your car’s electrical system. I don’t jump anything off my vehicles.
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The risk is eliminated or at least minimized if the good vehicle is NOT running during the jump. Yes, I know this is contrary to the instructions provided by "experts".
The problem is due to a phenomenon known as "load dump". When the dead vehicle is cranking, its starter is probably drawing 200 amps or so. The good vehicle's alternator will of course be "full fielded" to maintained output voltage with this very heavy load. When the cranking stops, all of a sudden the load on the good vehicle's alternator drops from 200 amps to something much lower. This causes a spike in the alternator output voltage for tens or even hundreds of milliseconds until the regulator reduces the field current to an appropriate value.
I will offer a jump from my vehicle, but it will NOT be running during the jump. This may provide a "weaker" jump but is much safer for my vehicle.
 
Short answer....yes, if you are Evel Knievel. If you are Napoleon Dynamite...ehhh...NO!

 
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