Hey guys, my PC 680 appears to have gone bad after only 18 months since I replaced it. The other one was about 8 years old before I replaced it. The only reason I replaced it was it seemed that it was not turning the prop as fast during start and I felt it was time to replace it. My charge voltage is about 14.2-14.4 during cruise RPM. At idle its 12.6 to 13, Oddessy recommends 14.4-14.8 volts. I fly about 1-2 times a week usually less than 1 hour each flt. I have a Ducatti VR installed in cockpit. When I take the battery home to charge (I do have the proper charger) it charges up quickly but will run down to 85% after sitting two days. Is there a better battery available that's not so sensitive to having 14.4-14.8 charge volts? Or could it be that I just had an inferior battery?
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Oddessy Battery Replacement
- Thread starter bobg56
- Start date
What do you mean by 85 percent? If after sitting for a few days, the battery
voltage is between 12.5 to 13, I would not worry about it as long as the engine
cranks well. The PC680 is not more sensitive to charging voltage than other
brands. Many Ducati regulators only put out 13.8 volts which is good enough.
Since the Rotax starts so quickly, the battery does not discharge very much.
voltage is between 12.5 to 13, I would not worry about it as long as the engine
cranks well. The PC680 is not more sensitive to charging voltage than other
brands. Many Ducati regulators only put out 13.8 volts which is good enough.
Since the Rotax starts so quickly, the battery does not discharge very much.
N282S
Well Known Member
pc 680s
Hi, Bob. To answer your question, there are alternative batteries. Here is a thread on the PC680 that will give you some light reading while turning your plastic gloves inside out and finding alternative toilet paper (sorry).
My post is #55. http://www.vansairforce.com/community/showthread.php?t=173617&highlight=pc680
And here is another thread on the 680s.
http://www.vansairforce.com/community/showthread.php?t=180078&highlight=pc680
My post is #3. I haven't fully tested the APEX but am happy so far. I currently have three, count 'em 3 PC 680 batteries sitting on my bench that failed in less than a year and a half.
And no, Larry, there is still no parasitic drag.
btw I too know how to figure percentages
Hi, Bob. To answer your question, there are alternative batteries. Here is a thread on the PC680 that will give you some light reading while turning your plastic gloves inside out and finding alternative toilet paper (sorry).
My post is #55. http://www.vansairforce.com/community/showthread.php?t=173617&highlight=pc680
And here is another thread on the 680s.
http://www.vansairforce.com/community/showthread.php?t=180078&highlight=pc680
My post is #3. I haven't fully tested the APEX but am happy so far. I currently have three, count 'em 3 PC 680 batteries sitting on my bench that failed in less than a year and a half.
And no, Larry, there is still no parasitic drag.
btw I too know how to figure percentages
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NinerBikes
Well Known Member
IMHO... because we too went through 2 in 5 months and 3 months, Odd, I see had a QC problem. They seem to have fixed it now. I would submit for warranty work, if you saved your receipt.
Also check your output of your Voltage Regulator, the Ducati brands tend to fail, some make it to up to 200 hours then poop out. Some sooner. Some go a lot longer.
The one thing that we do before shut down is run the motor up to 2500 rpm for 2 or 3 minutes before every shutdown, after a landing. Chopping the throttle to land, with all the lights on, tends to run the battery down, slightly, the rpms are not enough to keep the battery top charged on descent. So we run the motor up to a few minutes and watch the amp charge rate drop down to 1 or 2 amps before shutting down. Radio work on the ground also tends to draw a lot of current, compared to the whole system.
I would top charge that battery with a good charger, once every 6 months, to desulphate the lead in the AGM battery. Same thing people do with their RV's (Recreational Vehicles) when camping in them, off of the grid.
Also check your output of your Voltage Regulator, the Ducati brands tend to fail, some make it to up to 200 hours then poop out. Some sooner. Some go a lot longer.
The one thing that we do before shut down is run the motor up to 2500 rpm for 2 or 3 minutes before every shutdown, after a landing. Chopping the throttle to land, with all the lights on, tends to run the battery down, slightly, the rpms are not enough to keep the battery top charged on descent. So we run the motor up to a few minutes and watch the amp charge rate drop down to 1 or 2 amps before shutting down. Radio work on the ground also tends to draw a lot of current, compared to the whole system.
I would top charge that battery with a good charger, once every 6 months, to desulphate the lead in the AGM battery. Same thing people do with their RV's (Recreational Vehicles) when camping in them, off of the grid.
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NinerBikes
Well Known Member
Be sure to check and make sure your electric fuel pump fuse didn't pop or blow when you got the engine starter clicks. Both times the battery died, we blew the fuel pump fuses, too.
Bob Martin
Well Known Member
From ODYSSEY? Battery Technical Manual:
All ODYSSEY batteries can be quickly charged. Figure 7
on the next page shows their exceptional fast charge
characteristics at a constant 14.7V for three levels of inrush
current. These current levels are similar to the output
currents of modern automotive alternators. Table 6 and
Figure 7 show the capacity returned as a function of the
magnitude of the inrush3 current.
Standard internal combustion engine alternators with an
output voltage of 14.2V can also charge these batteries.
The inrush current does not need to be limited under
constant voltage charge. However, because the typical
alternator voltage is only 14.2V instead of 14.7V, the
charge times will be longer than those shown in Table 5.
The above may explain it somewhat...
Our alternators are putting out 14.2 or so and our typical GA flight is an hour or less.....we may be slowing discharging our batteries.
Walt
Well Known Member
For those lucky enough to have installed the B&C alternator, the output voltage is adjustable. I have mine set to 14.7v
Sam Buchanan
been here awhile
Is there a B&C alternator for the RV-12?
RFSchaller
Well Known Member
Have you tried lifting the positive lead and checking charge state after a few days? If it internally discharges it will be flat. If it?s a trickle discharge in your wiring it should remain charged.
Bob Martin
Well Known Member
Walt, I didn't mean to hijack a thread but I was interested in the Odyssey 680 issue bc I have several on the bench as well. Having a tired original auto conversion from Vans...I elected to go the B&C route with a seperate VR so it could be adjusted for this very reason.
While I was ordering over the phone from B&C I asked about this very topic. They consulted with the electrical staff engineer and called me back the next day to say it should be a non issue for the Alt to charge a few tenths of a volt less. Example was the current loss from the length of the main cable to the battery. In some planes it is a very short run and others it is in the rear of the plane. Should be a non issue.
Yet it remains.
In studying the Odyssey technical manual as I quoted above they actuall say it takes longer to charge up the Oydssey, thinking deep cycle AGM type battery, with less voltage....so combine that with short hops around the patch (1 hour) and we have a recipe for PC680 issues.
I too will be adjusting the B&C VR up to 14.7v
My .02
PC680
Mine work all the time. I have one that?s been in the 6 for 4 years. Judie won it at Petit Jean. I have one that?s been on a chicken coop door for two years and one on a 16 foot gate with solar chargers. They work every time unless there are several days of cloudy weather. 3 times in 2 years.
Mine work all the time. I have one that?s been in the 6 for 4 years. Judie won it at Petit Jean. I have one that?s been on a chicken coop door for two years and one on a 16 foot gate with solar chargers. They work every time unless there are several days of cloudy weather. 3 times in 2 years.
Piper J3
Well Known Member
Walt
Well Known Member
Oops, forgot this was the RV12 thread. Although I think I have seen an option for installing an optional alt somewhere.
I have the battery sitting on my work bench and each day the voltage has been dropping. The battery is bad no doubt but how did this happen? It could be that this one was poorly made, the other I replaced was about 8 years old. I have another on order and will see how long this one goes, I don't think I'd have this problem with a good old lead acid battery but I also don't want to deal with the corrosion issues with one. Once I get a hanger I will charge it every now and then, maybe that will extend the life.
RFSchaller
Well Known Member
Sounds like a warranty claim is in order.
