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RV-12 Low Voltage

pilotyoung

Well Known Member
I am new the the RV-12 having bought mine 3 months ago. The last couple of flights the voltage has been around 12.9 volts. It used to b e 13.9 volts.

Is this a symptom of the voltage regulator going bad?
 
If it is maintaining the 12.9VDC during the flight and carrying normal amp loads, then most likely yes - a VR issue. To confirm, you could borrow an alternator/regulator tester from your local auto parts store (AutoZone or Napa both loan/rent tools) and do a load test. Most of the modern test units will indicate regulator or alternator.
 
I am new the the RV-12 having bought mine 3 months ago. The last couple of flights the voltage has been around 12.9 volts. It used to b e 13.9 volts.

Is this a symptom of the voltage regulator going bad?

Yes, that is one of the early warning signs. If indeed the VR is failing you may want to cosider replacing it with a more robust unit than the original failure-prone component. I am on my second Ducati, and at my upcoming CI I have decided to premptively replace it with the Silent Hentnik unit from Germany. The SK unit has been discussed in this forum and has received good reviews. It is however quite a bit more expensive, but I am OK with that to get a permanent fix and reduce the possibilty of getting stranded off-site. My SK unit is coming via a motorcycle shop in the UK. They are very accomodating, and in fact volunteered to hand carry my unit across the pond on a pre-planned trip to save shipping costs. If you (or anyone else) is interested in piggy backing on this arrangement there may still be time. I will send you the details on request.
 
I really don't know anything about these voltage regulators. But I have read some remarks about using a John Deer regulator that is available on Amazon.

I would like to hear other people's thoughts and experiences with the John Deer unit?

Thanks.
 
I have the Silent Hektik regulator. It's very stable and electrically quiet, as it certainly should be given its price. The only thing I don't like is that it's designed for Li batteries, and steps the charging voltage up -- slowly -- from 12.7 to full voltage. That takes about 40-45 minutes in my case, so if you make a lot of short flights it may never get above the mid-13V range. I think they may make another version that doesn't step the voltage.

Now, having said that... my PC680 battery is now around 7 years old. I anticipated needing to replace it last year or this year... but it still holds about 12.6 to 12.7 V with no load. When I put it on the smart charger/conditioner, it shows it at 100% and healthy after a few minutes. It's tough to argue with that. I'm going to see about getting it load tested.
I would like to hear other people's thoughts and experiences with the John Deer unit?
The actual John Deere factory part isn't cheap either. Several people, myself included, have used cheap Chinese-produced clones available through Amazon and Fleabay, which appear to be identical to what NAPA sells (but I haven't checked that). Mine worked OK for a few months, then failed rather spectacularly a few minutes after takeoff one day. Like most cheap clone electronic devices, these things aren't the most robust design nor are they of the highest quality. It's a gamble.
 
Just checked my logbook... I replaced Ducati VR at 108TT with John Deere AM101406 bought for $20.00 w/ free shipping. Installed in same location on shelf under cowling. Now have 340TT with no problems. Good trade...

Correct wiring for JD AM101406.
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My JDs seem to have lasted about the same as my Ducattis but are a lot less expensive. The Silent Hektik VRs are a lot more expensive and hard to get. I might opt for one if they were easier to get hold of. I haven't seen any PIREPs on them though ...
 
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