Could my regulator be faulty.

[nickjaxe]

Hi guys,

My 503 is electric start and I coupled up my digital volt meter with the starter
battery today when I test ran my engine 503 Ducati electronic ignition SC,

I wanted to check what reg volts (std rotax reg alloy finned unit) I wanted to
see what volts it was putting into my battery, anyway started the engine and ran
it at 2500rpm, and for about 2 mins the voltage was upto 17.5v

Then all of a sudden as I was watching the rev counter it dropped a few hundred
rpm with NO drop in engine note and at the same time the battery volts went back
to what I would think as normal 13.9v steady,

I just dont want to harm my battery with high charging volts and am not sure if
what my charging system was doing was normal what do you think guys,

I leave my battery with coupled to a battery condition float charger 24/7, but
17.5v scares me, when the engine is running,

What do you think guys.

Nick.

[German]

Much too high!

[nickjaxe]

Even if its only at startup then after 1-2 mins its where it should be at 13.9v.

Nick.

[Morph]

100% your rectifier is gone. Don't run your plane like that too long, it cooks the battery.

There is a Zener Diode that is supposed to hold the voltage down to 13.9 V. That is no longer working.

[nickjaxe]

Hi Morph the voltage soon drops to 13.9v well when I tested it it was between 1 to 2 mins and it suddenly dropped to 13.9v, do you think that short a time will do damage.

Nick.

[Duck Rogers]

Nick.....if your battery is flat, or flattish, then the 1 minute or so at high voltage will do no harm, but in your case the battery should not be flat as you've said it's on trickle charge 24/7. Hitting the battery with this high voltage is the same as giving it a fast charge, for a short while.
If it continues doing it, then I would suggest you have the battery checked.

ps. I'm in the country and will be up North next weekend

[Morph]

Watch it carefully. This is symptomatic of a regulator failure, or in the process of failing. 2min now, 5 min next. I had mine go on a 2 hour flight. We started smelling fumes within the first hour, the end of the second the battery was beyond redemption. The battery will start overheating, the electrolyte will boil off, even in sealed batteries and the battery will begin to swell.

[nickjaxe]

Thanks for the advise guys I am going to look into it further,

Hi Duck the WX is terrible at the moment, its not stopped raining for the best part of a month with the worst rain in history in the Lake District sweeping away many road bridges, with a bit of luck it will all be gone by the time you get here.

Nick.

[Duck Rogers]

Thanks for the advise guys I am going to look into it further,

Hi Duck the WX is terrible at the moment, its not stopped raining for the best part of a month with the worst rain in history in the Lake District sweeping away many road bridges, with a bit of luck it will all be gone by the time you get here.

Nick.

In Edinburgh at the moment. Seen what Cockermouth looks like. Scary. From what I've seen so far, it doesn't look like clearing up........but then again, this is Britain. Clear now, rain later, cold, hot, overcast, snow......all in a day

Morph has a point....check the regulator as well. The point I was making is that if the battery is not full to start with, the regulator will give it as much as it wants on start-up till the battery is at the right level, then the regulator keeps it there where it's supposed to be. Switch it off and leave it for a couple of days, and the voltage drops on the battery and upon start-up the voltage from the regulator will be momentarily high again until the battery swallows up the difference it need to get back to full.

[nickjaxe]

Hi Duck no you have not picked a nice time to be over here but I hope you enjoy your stay, not been up to Scotland for many years, I must make the effort and you around the Scottish highlands beautiful.

As soon as the wx clears I will take another look with my tester.

Nick.

[SOUT (RIP)]

Hi ALL
I trust you are all in good health.

I was a witness of a sealed battery that burst open on the side because of a regulator / rectifier malfunction. .

regards
Sout
"there is no parking space for repairs above 1 foot off the ground"

[nickjaxe]

Been having a look at my reg today as its stopped raining in my part of the Uk at last, I did think I had sorted my overcharging prob when I found the earth for the reg was not as secure as it could be, sorted that ran the engine all seemed ok 13.9v,

I then gave the reg a tap with a spanner engine running and the voltage jumped to between 17-18volts so I still have a problem,

What am I best replacing the reg with, I have heard good things about Key West regs or stick with the Rotax unit, my 503 is the Ducati ignition version with electric start.

Nick.

[Duck Rogers]

Key West or Rotax.......same thing, works equally well, quality equally same. The one's just a little cheaper than the other, not by much if I recall correctly, though.

[Morph]

Sounds like a dry joint. As you start and it heat sup, expansion results in the contact being made and the voltage drops to normal. Pity the damn things are filled with resin. Now if someone has a clever way of removing the resin, a simple re solder would be an easy job.

[nickjaxe]

A very nice man has suggested a good idea to me, ie to do away with my battery
charging system altogether as my 14ah battery is only used for my electric
engine starter nothing else so there would be no drain on it after start-up, my trike is kept at home and is permanently
connected to a maintenance charger so its always fully charged,

So what would I need to do to do away with my charging system apart from
removing the Regulator, I am thinking about the yellow wires that carry the AC
current that run generator to the reg and not want to harm the generator its
self,

I would think my battery would be plenty man enough to start my engine several times in a day without problem before dropping to much in power,

The motor is a 503 with Ducati ignition,

What do you think guys.

Nick.