Edd, I don’t want to start a discussion on how to charge the batteries (as this would be off topic), but starting from the ALL position has some major disadvantages. One is that you might be hiding a problem with your starting battery; two is that if one battery is weak, you would be charging that weak battery from the strong one (you risk that if one is nearly dead, the other would not start the engine, either, but instead would discharge to equalise the voltage with the weak one).
No question (in my mind), the best way is to start from the starting battery (hence the name) and have the echo charger making sure that both batteries are charged properly. Some advocate to have the batteries split into “main” and “spare”. Many good marine batteries can be used as dual purpose. If you design your system this way, you start on the “main”, it gets charged by the alternator and the echo charger maintains the “spare”. If I remember correctly, you have a solar system, as well. Many charge controllers have a dual battery option and they can be setup to charge the “main” battery first and then charge the “spare” (mine has a selectable 50/50 or 90/10 split). If you are interested, you can check some of Main Sail’s articles on that topic at Sailboat Owners or at his web site (http://www.pbase.com/mainecruising/). Marek (in Ottawa) PS. Would “may the Force (May the 4th) be with you” apply, even if it is a day late? I know it is mixing the references... From: Edd Schillay via CnC-List Sent: Monday, May 05, 2014 10:58 AM To: [email protected] Subject: Re: Stus-List Mixed batteries Rich, Please do send around a diagram. I’m planning to do something similar — a 27 starting battery (as battery #2) and a 31 house bank (as battery#1). When I want to start and run the engine, I will do so on ALL. That way the alternator will charge both batteries. When sailing and “hanging out”, I would switch to 1 only. I have a solar panel and a dual battery regulator, which would connect to both. Two weeks to launch and still much to do….. All the best, Edd Edd M. Schillay Starship Enterprise C&C 37+ | Sail No: NCC-1701-B City Island, NY Starship Enterprise's Captain's Log On May 5, 2014, at 10:38 AM, Rich Knowles via CnC-List <[email protected]> wrote: The best method I have found and the least problematic from all points of view is to have a dedicated starting battery that does nothing else but start the engine, and a house battery that can be several batteries in parallel. Ideally the house batteries will all be identical. I feed the alternator directly to the house battery and use a device such as a Xantrex EchoCharge, a small regulator, to keep the start battery charged. A simple 1/both/2 off switch feeds the house load from either battery and acts as a combiner switch if needed. I have a diagram I can send you if you wish. I have wired many boats this way with no complaints or incidents. Rich Knowles Indigo. LF38 Halifax. NS On May 5, 2014, at 10:47, via CnC-List <[email protected]> wrote: In a pinch, I recently bought a 'starting' battery (Group 27) per my earlier post (no marine stores open after 6 on Saturdays) Then I decided to get a replacement for my dead Lifeline AGM battery. Of course, Murphy lurking about, I realized that my Zantrex Truecharge 40 wants all the batteries it charges to be the same since its charging schemes apply to all three outputs to the batteries. Before I pull the 'rope-a-dope' of returning the starting battery, I need some list advice: A lot of sailors suggest using a 'starting' battery exclusively for starting and using the house batteries for the house. I am aware that an AGM can be used for starting as well. However, if a 'starting' battery is better for this job (CCA, etc.) and the AGM is better for its job, how does one use a single charger like mine to satisfy different charging schemes? 2 chargers, a smarter charger that has outputs for different battery characteristics, or 'forgetaboutit" and charge both batteries as though the were both AGMs? Charlie Nelson Water Phantom C&C 36 XL/kcb [email protected] _______________________________________________ This List is provided by the C&C Photo Album http://www.cncphotoalbum.com [email protected] _______________________________________________ This List is provided by the C&C Photo Album http://www.cncphotoalbum.com [email protected] -------------------------------------------------------------------------------- _______________________________________________ This List is provided by the C&C Photo Album http://www.cncphotoalbum.com [email protected]
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