Cruisers Forum

Join CruisersForum Today

Thread Tools Rate Thread Display Modes
Old 17-12-2010, 12:02   #16
Registered User

Join Date: Oct 2007
Location: San Francisco
Boat: N/M 45
Posts: 236
Originally Posted by delmarrey View Post
Normally one does not want to take a battery below 75% anyway making a 100 A alt. fairly useless on a boat with only 2-3 standard automotive batteries. That's why I stated way early, and referring to a different thread "Unless you have a large battery bank (e.g. 1000 Ah) it would be over kill."
I'd take exception to the point above -

it's normal to run a deep cycle lead acid battery down to 50% discharge, then recharge battery to 80-85% of capacity; this keeps the charge rate at it's maximum efficiency (e.g., most power accepted by the battery per unit time). It's also normal to couple a hi-output alternator with an external regulator that is observing battery state (temperature, voltage).

I have used an Ample Power 105AH 12vDC hot-rated alternator controlled by Ample's external regulator, since 1994. I typically see that alternator kicking out 85-90 amps for 90 minutes at a time while recharging a 450AH battery bank (4 x 6v deep cycle golf cart batteries) when passage making I try to charge twice a day, once in the morning and once in the evening.

And yes, that alternator is in the engine room, along with the engine, and it does get hot

- rob/beetle

beetle is offline   Reply With Quote
Old 17-12-2010, 12:25   #17
Senior Cruiser
delmarrey's Avatar

Cruisers Forum Supporter

Join Date: Mar 2003
Location: Now in Blaine, WA
Boat: Modified Choate 40
Posts: 10,735
Images: 122
Here are some posts that might be of interest from an expert to deals in charging systems.

AGM and gel-cell performance notes

How "fast" you can reliably charge your battery.

Evaluating 12vdc Flooded-Cell Batteries

Understanding a model for battery charge acceptance

Faithful are the Wounds of a Friend, but the Kisses of the Enemy are Deceitful! ........
A nation of sheep breeds a government of wolves!

Unprepared boaters, end up as floatsum!.......
delmarrey is offline   Reply With Quote


Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
high output alternator on 3YM30 Yanmar? c.spots Engines and Propulsion Systems 13 01-04-2012 14:53
High Amp Alternator - Dedicated Double Pulley Belt dadidoc Electrical: Batteries, Generators & Solar 48 28-10-2011 05:34
Powered USB Hub vs Powered USB Cables Bryan Kemler Monohull Sailboats 2 20-01-2010 15:24
High Jinks on the High Seas seamjay Off Topic Forum 5 05-12-2008 04:35
Davit pulley turkish6 Auxiliary Equipment & Dinghy 14 28-03-2008 07:25

Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 12:44.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.