RevMaster charging EarthX Observation

[BRS]

While doing ground runs on the "Tool Shed" I made an interesting discovery.
This is a new RevMaster 2300 powering an ETX680C EarthX battery. A combination some are not too keen on.

My procedure is to start the engine and let the battery charge until the voltage rises to 14.1 and current drops to about 2 amps. But today I managed to confuse the regulator (so it seems). I discovered (happened twice once by accident once intensionally to test) that by starting the engine with the Alternator switch in ON position that the regulator let the battery voltage go clear up to 15+ volts. At that point I turned off the Alternator. After a few seconds I turned it back on and the regulation worked just fine 14.1 and < 2amps.

So, this is just a word of caution. If setup with a Lithium battery and R2300 be sure to start the engine THEN switch on the Alternator.

[onex28]

Do you have your regulators separated? When you did your test we’re you using both regulators when engaging the starter?
I’ve separated my regulators so I can use either separately or both.

[BRS]

Do you have your regulators separated? When you did your test we’re you using both regulators when engaging the starter?
I’ve separated my regulators so I can use either separately or both.

My Regulators are separated and are controlled by independent relays & switches. As it is, I only have one working Alternator as one was DOA from the factory. Yes, only one alternator was engaged at the time of this happening. Anyway, I'll continue to keep an eye on the voltages/amperages. It's nice having an efis with alarms.

The plane is ready to fly except I'm unsure of my high power mixture. I'm only getting ~3000 rpm on static run-up (prince-p, 54X50). What static rpms do you get?

[DJ_Theis]

I discovered (happened twice once by accident once intensionally to test) that by starting the engine with the Alternator switch in ON position that the regulator let the battery voltage go clear up to 15+ volts. At that point I turned off the Alternator. After a few seconds I turned it back on and the regulation worked just fine 14.1 and < 2amps.

So, this is just a word of caution. If setup with a Lithium battery and R2300 be sure to start the engine THEN switch on the Alternator.

I'll try to make this brief, although I need to send an extended email, or better yet a link to a web site my partner an I are putting together to address / document the R2300 alternator issues.

First, the advice regarding the slow charge after starting is (appears to be) a great start towards insuring the are no issues with ANY battery combination but particularly with the Lithium Ion variety.

Second, WRT to R2300 OEM regulator; I've done extensive evaluation of this regulator and although it appears to be a very simple, single phase, half wave regulator, it has a few smarts that apparently can cause a charge setpoint failure. VERY GOOD data point. Thanks Brock!!

The regulator by design will not pass current unless it is first connected to a battery. It has an internal sense circuit that inhibits charging unless there is a complete connection to a battery source. My experience is that complexity opens the door for unexpected failures like this. I can only imagine how this failure can occur but I will run a test and see if I can repeat the failure on the bench (I've set up a full R2300 alternator and charge system to try and figure this darn thing out...). I have little doubt that I will be able repeat this failure mode.

More on this as we learn more but if I have one word of caution to builders regarding the R2300 alternator it is "ventilation." While there are always compromises with any design, and the R2300 has its share, one of the most obvious is limited ventilation. I believe Revmaster is working on a field upgrade to address this issue.

I'll post within a couple days a site location for those interested in more details on the alternator / regulator.

Dan
Sonex 1362

[BRS]

...
I'll post within a couple days a site location for those interested in more details on the alternator / regulator.

Dan
Sonex 1362

Thanks Dan, do keep me updated to what you find. As for the regulation, I might consider installing one of the B&C AVC1 regulators.
eml: brs~at~one.nine.three.zero.one~dotNET

[mike.smith]

The plane is ready to fly except I'm unsure of my high power mixture. I'm only getting ~3000 rpm on static run-up (prince-p, 54X50). What static rpms do you get?

I was never able to get my static RPM on the ground to get up to what I get when flying. Perhaps it's because the prop has no forward motion and the prop is fully digging into non-moving air. If you are getting 3,000 rpm on the ground I expect you will get better in flight. I also got better rpms once the engine began to break in. I'm assuming because it was no longer as tight. Perhaps other have some other anecdotal observations to offer.

[onex28]

Brock, my 2300 manual states the slow aircraft should get 3200 static and faster aircraft should get 2900-3000 rpm. I get 3000 in my Onex with a 54 x 44 propsinc.com propeller.

David