Wynn Wynn

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NormanB

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Interesting You Tube video from the Wynns’ on their electrical system and in particular their issues keeping their batteries charged.

For those who can afford 17 minutes watching this and are of a technical disposition, you may be able to help them identify the real issue.

Link to Wynn’s YT Video
 
What issue? I didn't see one other than the fact they tested their alternator by idling the engine for a while then revving it up in neutral, which it probably won't like. They certainly aren't short of power, but they do use a fair amount.

Wasn't the video taken while in Panama, where it's cloudy almost 100% of the time.
 
The issue is their engine driven alternator which I believe is an 80A unit, is only providing 27 A charge at the batteries (with the engine at 2000rpm) whereas their generator (many more KW capacity) is providing 100 A charge to the batteries.
 
Yes that did seem poor. Isn't alternator output specified at a certain RPM. I doubt both alternators are bad. It's probably either dodgy cables (I found one of mine almost worn through :eek:), or a bad setup
 
NormanB said:
The issue is their engine driven alternator which I believe is an 80A unit, is only providing 27 A charge at the batteries (with the engine at 2000rpm) whereas their generator (many more KW capacity) is providing 100 A charge to the batteries.
Click to expand...

The alternator should be capable of supplying more current at that speed, however the actual charging current into the batteries depends entirely on the voltage reaching the batteries, which wasn't mentioned. As there are twin alternators, it's possible there may be diode isolators dropping the voltage too.
 
pvb said:
The alternator should be capable of supplying more current at that speed, however the actual charging current into the batteries depends entirely on the voltage reaching the batteries, which wasn't mentioned. As there are twin alternators, it's possible there may be diode isolators dropping the voltage too.
Click to expand...

as is common with all this sort of stuff there is insufficient facts to really pin anything down in a sort of 'Gotcha' and they do not go into detail on the 'charging controller' if it is common taking inputs from the main engine alternators or the generator unit, OR if there is a dedicated charge controller for each source. If there is only one charge controller which allows 100 A to pass to the batteries then it should, all things being equal, allow almost 80 A from an engine alternator or 100 A when both engines are running from two alternators.
 
Since I have a shinny new clamp meter I've been playing around and found that my alternator will kick out roughly 50 amps right from low down in the rev range. There is a tiny loss from the alternator controller but nothing much.

Of course it will only kick out that much current if it is required. Once the batteries are charged it drops to about 3 amps or less.

Engine is a Yanmar 3GM30 with what I thought was I was 50 amp alternator unit.
 
Mikedefieslife said:
Since I have a shinny new clamp meter I've been playing around and found that my alternator will kick out roughly 50 amps right from low down in the rev range. There is a tiny loss from the alternator controller but nothing much.

Of course it will only kick out that much current if it is required. Once the batteries are charged it drops to about 3 amps or less.

Engine is a Yanmar 3GM30 with what I thought was I was 50 amp alternator unit.
Click to expand...

I have a Yanmar 3GM30F with the standard alternator. Early in the morning when solar energy has not begun and the fridge has been on all night the voltage in my bank of 3 x 120 Ah batteries is typically 12.3 - 12.4. On starting the engine the charging current will briefly be 55 amps, rapidly reducing within well under a minute to maybe 20+ amps and down to less than 10 amps in an hour.
 
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