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Trouble starting

P

prkaye

Well Known Member
The last couple of flights when starting the cranking has been very sluggish. This morning it was barely turning over, but I got it started. I did a 25 min flight and the EFIS was reporting a steady voltage of 14.6V. No issues in-flight. Immediately after shut-down the EFIS was showing about 12V. I tried starting it again. During cranking the EFIS showed the voltage dropping to between 1V-2V.
Does this sound like a bad battery, or could it by my alternator or starter?
All components including battery, starter and alternator are 6 years old. The battery has been stored at room temperature during the winter (non-flying) months.
 
A fully charged battery should show ~12.5 vdc across the terminals with no load. You discribe a battery ready for recycle. After six years it no longer owes you anything!

Carl
 
Sounds like the battery. Try putting a proper charger on it (see battery MFG site) and let it charge for a day.

While it is charging, look for loose and/or corroded connections. Cables can corrode internally, which won't be visible.
 
Carl Froehlich said:
A fully charged battery should show ~12.5 vdc across the terminals with no load. You discribe a battery ready for recycle. After six years it no longer owes you anything!

Carl
Click to expand...

+1
A failing battery is a match with those symptoms, though apparently you cannot trust what your efis is reporting during cranking. Your starter won't move an inch with 1-2 volts. If you got that reading with the starter not turning, it is believable.

Larry
 
Thanks guys. I guess I just expected the battery to last longer than 6 years. I'll get a new one, and double-check all connections when I install it.
 
prkaye said:
Thanks guys. I guess I just expected the battery to last longer than 6 years. I'll get a new one, and double-check all connections when I install it.
Click to expand...
You may be expecting too much.
I replace one of my two PC-625 batteries every two years. That translate to neither one being more than four years old. This provides some assurance for electrical reserve.
The pulled battery finds another four years or so of service in lawn tractors and such.

Carl
 
one pirep

Phil,
I had a concorde rg-25 for about 6 years, totally abused by only in-flight charging - short hops, and sitting in the plane most winters.
finally just thought I was pushing my luck, and bought a PC-925 which was more crank for the same weight.
I thought this was a good source 2 years ago....ymmv

http://saskbattery.com/

free shipping eh?
 
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Battery

I replace the battery every 3 years. $100 is cheap insurance vs it going tu when needed. I think its likely harder on a battery sitting so much like planes do vs firing up and running daily like cars do. Bad batteries can lead to other issues so i say get a new one and be happy. Just a note that you dont have to order from spruce etc, its a very popular battery and likely a snowmobile or tractor supplier or battery specialty shop has them local and can get you a good price with no hazmat shipping hassles.
 
If you want a reliable battery, get a battery LOAD tester from harbor freight and load test your battery every year. It will tell you when you should replace the battery.

Always fully charge your battery before you load test it the next day.

Bad connections from the battery can mimic a bad battery.

A good volt meter will tell you when your battery is not holding a 12.8 volt charge..... Test at the battery terminals with nothing on.
 
gasman said:
If you want a reliable battery, get a battery LOAD tester from harbor freight and load test your battery every year. It will tell you when you should replace the battery.

Always fully charge your battery before you load test it the next day.

Bad connections from the battery can mimic a bad battery.

A good volt meter will tell you when your battery is not holding a 12.8 volt charge..... Test at the battery terminals with nothing on.
Click to expand...

Excellent advice.

6 years sounds pretty good, but seeing a voltage reading of 1-2 volts while cranking is a strong indicator of bad connections somewhere.

Worth noting is the fact that a bad connection in the right place can result in a system capable of starting the engine, but slowly running the battery down in flight (because charging current can't make the round trip from alt through bat & back).

Charlie
 
Good advice on load testing the battery before you start throwing parts at it. Also the battery should be at 12.6 fully charged but might easily show 12.0 at the efis due the normal voltage drop between the battery and all the relays, switches etc between the two.

Tim Andres
 
just before osh i replaced a 3 year old odyssey 680. got every start possible from it.
IMG_0464%20copy.jpg
 
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