Alternator upgrade on Westerbeke 40A

jvoelxen · **Joined:** 21 Oct 2006 15:36 **Posts:** 268

Mainsail-
I agree with what you say but if you choose to have separate banks both of which that need charging you need to sense voltage of the bank being charged. Seems to me the only way to do that is by sensing the voltage at the battery switch's common pole. Am I missing sometjing?

Maine Sail · **Joined:** 16 Oct 2011 13:33 **Posts:** 12

jvoelxen wrote:

Mainsail-
I agree with what you say but if you choose to have separate banks both of which that need charging you need to sense voltage of the bank being charged. Seems to me the only way to do that is by sensing the voltage at the battery switch's common pole. Am I missing sometjing?

Most high performance installations today will utilize an ACR, Echo Charger or Duo Charger type of automatic device to charge a second AUX/Start bank. These devices will work with solar, wind and shore charger as well as the alternator and are fully automatic thus requiring the owner to do less manual "switching" which can lead to errors.....

Even with a 1/2/BOTH switch you can still charge the start battery by using the BOTH position. However if you switch to #2 you would not also be charging #2 if the alt was on HOUSE/#1 unless you had an ACR, Echo or Duo type device...

Running the alt through the battery switch is a compromise that is easy for the factories and works with a self sensed alt. When you get into a high amperage alternator, most installations will feed direct to the house, and remote v-sense the house, then charge the start batt automatically via one of the above mentioned devices.

Tortuga's Lie · **Joined:** 27 Oct 2006 10:32 **Posts:** 827

Many cruisers are now eliminating the starter bank of batteries and increasing the house bank since many have multiple charging sources and the chances of not having enough juice to start the engine is now minimal. I haven't gone this route yet but it would limit the switching issues and maybe reduce weight a little.

On another related note, I was just reading about calibrating the tachometer with the new alternator and this method sounds fairly simple:
http://pages.suddenlink.net/kmielen/C320Docs/Tach.htm

Maine Sail · **Joined:** 16 Oct 2011 13:33 **Posts:** 12

Tortuga's Lie wrote:

Many cruisers are now eliminating the starter bank of batteries and increasing the house bank since many have multiple charging sources and the chances of not having enough juice to start the engine is now minimal. I haven't gone this route yet but it would limit the switching issues and maybe reduce weight a little.

I have a lot of cruising customers and I don't have any that have gone that route yet. Personally its not a method I would choose especially when a single G-24 or 27 can easily start a sailboat AUX motor and power some house loads if necessary...

This is even more true with a series only bank where if you lose one cell the bank is done.. With a parallel bank you could lose one batt, and if competent, figure out which one and isolate it but not so much with a series bank.

Tortuga's Lie wrote:

On another related note, I was just reading about calibrating the tachometer with the new alternator and this method sounds fairly simple:
http://pages.suddenlink.net/kmielen/C320Docs/Tach.htm

Digital photo tachs are now quite inexpensive, about the price of a bottle of booze or wine....

http://www.amazon.com/Digital-Photo-Laser-Tachometer-Contact/dp/B000EUT9ZS

I paid over $200.00 for mine about 20 years ago but in the mean time the Chinese figured it out... Very Happy

I usually leave my customers with a tach deviation card as they are not always spot on throughout the entire range. You get them as close as possible then make a deviation card....

Tartan37.com

Alternator upgrade on Westerbeke 40A

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