Chuck I was charging two 31s with my 35 amp alternator. When I had problems with my system I put in a 50 amp instead. Non OEM alternators are cheap. I'd rather have 2 house batteries than risk killing one at a time.
Joel 35/3 Annapolis On Wed, Apr 6, 2016 at 4:11 PM, Chuck Gilchrest via CnC-List < cnc-list@cnc-list.com> wrote: > Bruce, > > My boatyard says it puts a very heavy load on the alternator to charge > both house and starter batteries at the same time using the diesel. Same > if you have two house batteries hooked up in parallel. If you’ve installed > a high output alternator on your diesel or have alternate charging methods > (shore power battery charger, solar panel, etc.) there’s less issue, > although I’m of the understanding that batteries being charged together > should be the same capacity and relative age. > > > > On my “new boat”, it came with 2 group 31 (house) and one group 24 > starter. It has a Promarine charger that runs off 110 current. The PO > spent most of the time hooked up to shore power and even had a Tenma 12v > power source that he could run the 12v circuit when he had access to 110v > shore power. I’m going to be on a mooring and I’m being told that unless > I can somehow upgrade my charging system, It is a bad idea for me to have > two Group 31 batteries in parallel as it will burn out the stock 35A > alternator on the Yanmar 3HM. I’m buying new batteries so now is the time > for a decision. Will probably go with one Group 31 for the house and one > Group 24 for the starter. There’s a two battery switch on the bulkhead so > I can assume the second Group 31 was wired in parallel on the same switch. > > > > I’m trying to avoid turning my lovely Landfall 35 into a Beverly > Hillbillies looking stern (my wife insisted we buy davits) by adding wind > generators, solar panels along with all the other “essential” debris that > clutters up a cruising boat. The boat has 12V refrigeration (OEM Waaco > Cold Machine) that would be wonderful to turn on occasionally to keep a few > things cold while cruising. Does anyone out there charge a pair of Group > 31 batteries using the lower output alternator? > > Chuck Gilchrest > > Half Magic > > 1983 LF 35 > > Padanaram, MA > > > > *From:* CnC-List [mailto:cnc-list-boun...@cnc-list.com] *On Behalf Of *Bruce > Pope via CnC-List > *Sent:* Wednesday, April 6, 2016 3:44 PM > *To:* cnc-list@cnc-list.com > *Cc:* Bruce Pope <brucep...@live.ca> > *Subject:* Re: Stus-List Automatic Charging Relay > > > > > > Is it safe to switch between 1-BOTH-2 while the engine is running? I have > gotten mixed messages about that. Haven't tried and am starting/charging > in the BOTH position assuming therefore that banks are in parallel and both > are charging. But, read somewhere that it is bad form to charge different > types of batteries (starter/deep cycle house) this way. > ------------------------------ > > *From:* CnC-List <cnc-list-boun...@cnc-list.com> on behalf of Josh > Muckley via CnC-List <cnc-list@cnc-list.com> > *Sent:* Tuesday, April 5, 2016 7:58 PM > *To:* C&C List > *Cc:* Josh Muckley > *Subject:* Re: Stus-List Automatic Charging Relay > > > > It's not "smart" it always starts charging the "primary" bank first. Once > the primary battery is full (ish) it combines the second battery. > > Josh > > On Apr 5, 2016 9:50 PM, "John Pennie via CnC-List" <cnc-list@cnc-list.com> > wrote: > > Thanks Gary. I get that and I suppose it certainly simplifies the wiring > - you essentially have one bank for charging purposes. No opinion at this > point although I do feel silly having spent the last year dutifully > switching between 1-both -2. I assume it’s just a relay that connects the > circuit at a set voltage. Not sure how it can be smart enough to determine > which bank to charge first but perhaps they are more than just a relay. > > > > John > > > > On Apr 5, 2016, at 9:13 PM, Gary Russell via CnC-List < > cnc-list@cnc-list.com> wrote: > > > > Hi John, > > I've had ACRs on my boats for the last 15 years and I think they are > one of the best upgrades you can do. When I bought "Kaylarah" (formerly > "High Maintenance",adding and ACR was one of my first upgrades. They are > usually wired to charge the house bank first, then the start bank. If your > start bank was very low, you could could still use a combine switch to get > the engine started. I have never had a problem with the ACRs and I can't > say the same about a 1-BOTH-2 switch. All you have to do is forget to > switch to 1 or 2 after you shut the engine off and you can kill both > batteries while sitting on a hook. That won't happen with and ACR. I > think you will come to like them. > > > > Fair winds, > > Gary > > S/V Kaylarah > > '90 C&C 37+ > > East Greenwich, RI, USA > > > ~~~~~~~_/)~~~~~~ > > > > On Tue, Apr 5, 2016 at 8:38 PM, John Pennie via CnC-List < > cnc-list@cnc-list.com> wrote: > > So while connecting batteries today i discovered, to my surprise, that > Paws has an automatic charging relay between the two battery banks. Yes, > I’m still learning this boat. So as I understand it, once voltage hits > 13.6 volts (or 13.0 for 2 minutes) the relay will automatically combine the > two banks to share the changing source. Not sure how I feel about that. > > On the plus side, I guess it’s great that I don’t have to worry about > moving a battery selector switch while the engine is running. On the down > side - > > How does a battery charger monitoring two banks handle this? I just seems > it has to screw up the logic on the charger. > Essentially there is no way to isolate charging? So if I know I only have > limited time to charge and want to concentrate on one bank I have no choice? > > What I missing? > > John > > > _______________________________________________ > > This list is supported by the generous donations of our members. If you > like what we do, please help us pay for our costs by donating. All > Contributions are greatly appreciated! > > > > _______________________________________________ > > This list is supported by the generous donations of our members. If you > like what we do, please help us pay for our costs by donating. All > Contributions are greatly appreciated! > > > > > _______________________________________________ > > This list is supported by the generous donations of our members. If you > like what we do, please help us pay for our costs by donating. All > Contributions are greatly appreciated! > > > _______________________________________________ > > This list is supported by the generous donations of our members. If you > like what we do, please help us pay for our costs by donating. All > Contributions are greatly appreciated! > > -- Joel 301 541 8551
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