Alternator Sense Wire

[larmistead]

Hi all,

I'm upgrading a Beneteau 331 electrical system per the generally "accepted wisdom" here. I now have a house bank with two 4Ds in parallel and a separate start battery. I've installed a battery monitor and a Xantrix echo charger. I've run a new cable from the alternator to the start battery bank. All seems to be well. For now, I'm retaining the stock alternator, an Arco 86050 50 amp. It's hard to see the back of it but it appears to be a "one wire" unit with connections to the starter switch panel, tach and battery. I'm thinking the regulator's sense wire is internal and inaccessible to connect it to the house bank. Can someone tell me if this is true?

Can I get by with this until I get the gumption (and $) to upgrade the alternator. I read that there are problems doing this with the Westerbeke 30. Comments???

Thanks,
Leigh

[goboatingnow]

Originally Posted by larmistead

Hi all,

I'm upgrading a Beneteau 331 electrical system per the generally "accepted wisdom" here. I now have a house bank with two 4Ds in parallel and a separate start battery. I've installed a battery monitor and a Xantrix echo charger. I've run a new cable from the alternator to the start battery bank. All seems to be well. For now, I'm retaining the stock alternator, an Arco 86050 50 amp. It's hard to see the back of it but it appears to be a "one wire" unit with connections to the starter switch panel, tach and battery. I'm thinking the regulator's sense wire is internal and inaccessible to connect it to the house bank. Can someone tell me if this is true?

Can I get by with this until I get the gumption (and $) to upgrade the alternator. I read that there are problems doing this with the Westerbeke 30. Comments???

Thanks,
Leigh

Yes , its "internally or machine sensed", thats the most common sense system.

Given the system you have , just transfer the alternator charge supply to the domestic bank, and let teh echo charge take care of the starter battery.

Battery sensing is only a "nice to have", unless you have diode splitters or whatnot in the circuit , which you dont have.

Make sure your batteries share a common negative, The field excite , which is fed via the start switch , can still come from the starter battery, its not a big deal.

dave

[hellosailor]

Dave-
"Battery sensing is only a "nice to have", unless"
Without battery sensing, all you can have is a bulk charge, no?

[goboatingnow]

Originally Posted by hellosailor

Dave-
"Battery sensing is only a "nice to have", unless"
Without battery sensing, all you can have is a bulk charge, no?

No, battery sensing , just means that the voltage the regulator measures is at the battery terminal , rather then at the output of the alternator. Hence it can compensate for voltage drops in the transmission path from alt to battery.

How your alternator regulates battery charging has nothing to do with that.

Most alternators have just an upper voltage limit , they bulk charge , then absorption charge to that voltage limit, It can be anywhere from about 13.5V to over 14 on some alternators.

dave