How does one charge the battery in a twin?
The logical idea seems to have the battery connected to the bus, and
both alternators supplying current (and thus power) to the bus. However
alternators have a regulator, mostly built-in, that regulates the field
so as to produce a constant voltage even if load and rpm vary. But it
would be impossible to have both alternators controlled to produce
exactly the same voltage; and as soon as there is a difference, the
greater part of curent will come from one alternator, causing higher
load and premature wear.
Is this a theoretical concern only? Does one need to install TWO
batteries, with buses normally separated, as apparently is done in (at
least some) biz-jets?
Sorry if the point is moot, or the question silly, I was just wondering.
Not that I'll be be building a twin anywhere soon...

"jan olieslagers" > wrote in message
...
> How does one charge the battery in a twin?
> The logical idea seems to have the battery connected to the bus, and both
> alternators supplying current (and thus power) to the bus. However
> alternators have a regulator, mostly built-in, that regulates the field so
> as to produce a constant voltage even if load and rpm vary. But it would
> be impossible to have both alternators controlled to produce exactly the
> same voltage; and as soon as there is a difference, the greater part of
> curent will come from one alternator, causing higher load and premature
> wear.
> Is this a theoretical concern only? Does one need to install TWO
> batteries, with buses normally separated, as apparently is done in (at
> least some) biz-jets?
> Sorry if the point is moot, or the question silly, I was just wondering.
> Not that I'll be be building a twin anywhere soon...

The light twins that I've seen, as well as the King Air, use one
battery--even tough is is sometimes a pair of 12 volt batteries stacked in
series to make a single 24 volt battery.

I've been away from that field too long and no longer recall whether you
could find sufficient information in a POH to understand the method used; or
whether you would require a service manual.

Perhaps one of the A&Es on the forum will shed some light.

Peter

Peter Dohm schreef:
>
> Perhaps one of the A&Es on the forum will shed some light.

Thanks for your kind reply, Peter. But I am a bit disappointed in the
silence that followed...