It sounds like you have the old-style set up, so the engine will likely start on battery 1, battery 2, or both. The alternator will charge whichever battery the switch is on when you start. Based on the statement from the PO, perhaps he did a workaround to start the engine. You need to figure this out.
It's a good idea to develop a battery management system (how you ordinarily do things) to keep track of which battery you typically use to start the engine, run house DC, etc. The key is to make sure one of your batteries always has enough juice to start the engine. Complicating matters, as someone noted you should not switch to a different battery while the engine is running for fear of blowing your alternator. I've been on two boats where this has happened, so it's not just a myth. Something else to consider as an ultimate backup is a jump starter. I have a NOCO unit onboard for this purpose. Good luck! P.S. If you have the old-style C&C windows, you may want to consider Lewmar opening ports as an upgrade. It made a huge difference on my 34 reducing the heat down below on hot days. -----Original Message----- From: Floersch.net <n...@floersch.net> Sent: Saturday, June 21, 2025 11:12 AM To: Stus-List <cnc-list@cnc-list.com> Cc: Matthew Wolford <wolf...@erie.net>; Stus-List <cnc-list@cnc-list.com> Subject: Re: Stus-List Re: Alternator Question It is not green. We have two batteries and a 1-2-all switch. I’ll try to post some photos the next time I get to the boat. Might be a few days. -Nick Sent from my iPhone > On Jun 21, 2025, at 8:53 AM, Matthew Wolford via CnC-List > <cnc-list@cnc-list.com> wrote: > > I had a 1978 C&C 34 on which I installed a Blue Sea system switch to control > an extra engine-dedicated battery (while leaving the old 1-2-all switch in > place for the house bank). I also installed Lewmar opening ports. Is your > boat green by any chance? > > -----Original Message----- > From: Floersch.net via CnC-List <cnc-list@cnc-list.com> > Sent: Friday, June 20, 2025 11:57 PM > To: Stus-List <cnc-list@cnc-list.com> > Cc: Floersch.net <n...@floersch.net> > Subject: Stus-List Alternator Question > > Hi folks! > > Our CNC ’34 from 1978 … has an Atomic 4 engine. > > Last summer we finally installed solar panels! What a relief! Before that the > only way the battery charged was via the alternator. > > Now our battery is always (basically) getting charged… even if we do not use > the boat for a week. > > Cool. > > So the question is this… the previous owner told us that we MUST turn on > these "various switches" to enable the alternator charger system prior to > using the engine. The vague statement was along the lines of “if you do not > flip on the switches, then the alternator won’t charge the batteries, and > ‘it’ will burn out.” > > We are not sure what “it” is or if this makes any sense. I can understand, > kinda, if the alternator is generating electricity and has no sink to dump it > into… maybe that is bad. But a battery is not an unlimited sink for the > energy, so I can’t imagine how flipping the switches saves from burn-out of > some component. > > Does anyone else have some sort of switch or set of switches that must be > turned on before you start the motor to make sure your alternator is happy? > Or did we misunderstand the previous owner? > > (Yes I realize there is a lot f vagueness to this… but perhaps it will make > sense to someone, so I’m putting it out there to see what you throw back at > me :) > > Nick in Vermont > Your contributions help pay the fees associated with this list and help to > keep it active. Please help by making a small contribution using PayPal at: > https://www.paypal.com/paypalme/stumurray All contributions are greatly > appreciated. > Your contributions help pay the fees associated with this list and help to > keep it active. Please help by making a small contribution using PayPal at: > https://www.paypal.com/paypalme/stumurray All contributions are greatly > appreciated. Your contributions help pay the fees associated with this list and help to keep it active. Please help by making a small contribution using PayPal at: https://www.paypal.com/paypalme/stumurray All contributions are greatly appreciated.
