Hi Josh,
I don't use a 1-all-2 battery switch. I hate them. I use a
Blue Sea Systems Dual Battery Bank Management Panel
http://www.defender.com/product.jsp?path=-1|328|2290000|2290006&id=151145
with an ACR. The Blue Sea Battery Panel has separate switches for both
banks and a switch to combine the batteries.
Gary
~~~~~~~_/)~~~~~~
On Wed, Mar 22, 2017 at 4:38 PM, Josh Muckley via CnC-List <
cnc-list@cnc-list.com> wrote:
> Gary,
>
> How do anticipate switching the house to start...and not having that
> option in reverse? With the typical OEM 1,All,2 switches we're stuck with
> batteries in parallel. With the Don Casey method either battery can be
> disconnected and the loads cross-tied.
>
> I think I recall the reason for putting the house as primary. During the
> bulk charge phase the ACR or echo-charge are disconnected which means that
> the full charge current is applied to the primary battery. If you had a
> larger house and a tiny start battery and your alternator or other charge
> source was sized for the larger house capacity to minimize charge duration
> then you would be able to exceed the max charge current of your start
> battery (if it was setup as the primary) until it was up to 13 and the ACR
> closed in. With a sufficiently large difference in size and a
> significantly discharged house battery after the ACR closed in you could
> create a situation where the start battery voltage would be pulled down
> enough to immediately reopen the ACR. None of this is an issue in Bruce's
> case since both batteries are the same size. He will also probably find
> that his alternator is attached to the Off, 1,All,2 switch such that the
> alternator simply goes to whichever battery is selected.
>
> Josh
>
>
> On Wed, Mar 22, 2017, 3:46 PM Gary Russell via CnC-List <
> cnc-list@cnc-list.com> wrote:
>
>> Hi Josh,
>> I had read that the Primary battery should be the House battery but
>> I don't recall the article describing why. However, with the House battery
>> as primary, you can always switch to it to start the engine should the
>> Start battery fail. If the Start battery is Primary and fails, the ACR may
>> not be able to charge the House battery and you are out of options to start
>> the engine.
>>
>> Gary
>> S/V Kaylarah
>> '90 C&C 37+
>> East Greenwich, RI, USA
>>
>> ~~~~~~~_/)~~~~~~
>>
>>
>> On Wed, Mar 22, 2017 at 2:02 PM, Josh Muckley via CnC-List <
>> cnc-list@cnc-list.com> wrote:
>>
>> You have two different load requirements. First and most important is
>> when the boat is on the mooring. You'll want the bilge pump to work
>> automatically. That's all. You're not running any other loads when you're
>> not there. 50w is sufficient to keep the batteries topped up and handle the
>> occasional bilge pump. Be aware that 50w panels make ~4.2amps at 12v under
>> perfect conditions. Aim the panel, clean, no shade, high noon, at the
>> equator, no atmospheric blockages. My 100w panels rarely make more than
>> 6amps but are not meeting hardly any of the perfect conditions. If we
>> assume that your 50w will produce 3amps and the batteries are in good
>> condition and the bilge only needs occasionally pumped (no major mast,
>> deck, or shaft seal leaks) then 3 amps will keep up... with little margin.
>> The solar may create current for more than 8 hours and it may exceed 3amps,
>> but for estimating sake lets assume 24 Ah and then round down to 20Ah per
>> day.
>>
>> Your second load requirement is while sailing/cruising. That's all the
>> rest of the electronics and navigation lights. 50w is a completely
>> insufficient. But... While you're "using" the boat you are also running
>> the engine to get in and out of port (or on and off the hook). The
>> alternator is making up for the used energy at a minimum of 30amps. This
>> is usually very sufficient. Your house battery is ~100Ah and you'll want
>> to avoid discharging it more than 50% (50Ah). Less than 80% full is the
>> only condition in which the alternator will charge at full current so
>> basically 30Ah (50% to 80%) or 1 hour of engine operation, which between
>> coming in and going out is not hard to imagine.
>>
>> The controller you've selected is larger than necessary. Your 50w panel
>> is NEVER going to produce more than 5 amps. The BlueSolar is 3x larger
>> than needed. I would suggest looking a Genasun gv-4. It is appropriately
>> sized for your panel. https://genasun.com/all-products/solar-charge-
>> controllers/for-lead/gv-4-pb-4a-solar-charge-controller/
>>
>> Genasun has a design heritage from MIT's solar car competition. The gv-4
>> doesn't use electrolitic capacitors and is built to be marine grade. This
>> makes it ultra reliable.
>>
>> Many of the listers like the echo-charge. I'm sure it is a fine product
>> but I prefer an ACR. The echo-charge is only capable of charging at 15amps
>> max. An ACR will charge at full charge current. The solar, ACR,
>> alternator, and battery charger should all be attached to the starting
>> battery. Once the starting battery has reached its 80% full or greater
>> voltage (~13.3v) the ACR will CONNECT the house battery in parallel with
>> the start battery and continue to charge. This ensures that the most
>> important battery gets charged first and then they both get topped up and
>> maintained equally. The only caveat to the ACR being a "better" option is
>> if you are using different battery chemistries for start and house. But if
>> that was the case then you'd also have to have special charge controllers
>> for your alternator, solar and battery charger. Based on your description
>> I have assumed that you are using standard lead-acid batteries.
>>
>> All of this leaves the DC system vulnerable to a failure of the starting
>> battery. Under this setup there is no way to charge the house without the
>> starting battery and there is probably not already a good way of cross
>> connecting the house and start. The "All" position of Off,1,All,2 switches
>> just connects both batteries together. In a failed battery situation this
>> will draw down and possibly drain the house battery. Don Casey makes a
>> good argument for eliminating the Off,1,All,2 switches which are so
>> popular. He suggests single pole, single throw disconnect switches
>> arranged to separate each battery from their "bus" individually. Then you
>> would use another disconnect switch to cross-tie the busses.
>> https://www.amazon.com/dp/B00445KFZ2/ref=cm_sw_r_cp_apa_eoQ0ybTYDYCR2
>> In the event of a failure of either your house or starting battery you
>> could use the switches to align your batteries to the appropriate loads.
>> IMO, In this setup you would want your ACR, alternator, charger, and solar
>> all attached to the starting battery BUS instead of the battery itself.
>> Because of the switch setup when/if your start battery failed you would
>> open the start battery disconnect and close the cross tie. All of the
>> charging circuits would now be connected to the house battery with no need
>> to consider how it would be charged.
>>
>> There is some disagreement about which battery should be the "primary"
>> and which should be "secondary". Primary being where all the charging
>> sources come in, secondary being the battery which gets charged by the
>> echo-charge or ACR. Above all, I want my starting battery to get charged.
>> In my mind it is always first. In the attached picture, Don Casey has
>> drawn what I described. The picture I attached shows the starting battery
>> as the secondary and the alternator being directly tied to the house
>> battery - not on a switch. This avoids blowing the alternator diodes
>> should a switch be inadvertently opened during engine operation but doesn't
>> solve the reliability problem in the case of a primary battery failure.
>>
>> I'm not sure that it significantly matters but hopefully someone will
>> chime in on the merits of having the house battery as the "primary" and
>> hopefully also the merits of having the alternator directly connected.
>>
>> Good luck,
>> Josh Muckley
>> S/V Sea Hawk
>> 1989 C&C 37+
>> Solomons, MD
>>
>>
>> On Mar 22, 2017 11:23 AM, "Bruce Whitmore via CnC-List" <
>> cnc-list@cnc-list.com> wrote:
>>
>> On our 27 MKIII we mounted a semi flexible pane that could be walked on
>> to the sliding hatch and tied in a small charge controller and battery
>> combiner. We kept 2 series 24s and a series 27 charged on a mooring in
>> Chicago for 10 years this way. It kept the panel out of the way and we
>> just tied the boom off to one side when we left the boat.
>>
>> Kindest Regards,
>>
>> Bruce
>> 847.404.5092 <(847)%20404-5092>
>>
>> Please forgive any typos as this was sent from my iPhone.
>>
>> On Mar 22, 2017, at 10:37 AM, Edd Schillay via CnC-List <
>> cnc-list@cnc-list.com> wrote:
>>
>> Tom,
>>
>> Sounds like a good system. The only different thing I have in my setup is
>> a Blue Seas ACR instead of the Echo charger. See:
>> https://www.bluesea.com/products/7610/SI-ACR_
>> Automatic_Charging_Relay_-_12_24V_DC_120A
>>
>> Works VERY well.
>>
>> Another factor is the placement of the solar panel. A shadow from a boom
>> will give you a significant drop in volts.
>>
>> Smith sailing to Snow Goose! Rest in Peace Artie Karpf.
>>
>> 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 <http://enterpriseb.blogspot.com/>
>>
>>
>>
>>
>>
>>
>>
>>
>> On Mar 22, 2017, at 10:27 AM, Thomas Delaney via CnC-List <
>> cnc-list@cnc-list.com> wrote:
>>
>> Hi Listers,
>>
>> Snow Goose spent the last 20 years docked in a slip with shore power, and
>> I'm moving her to a mooring. I plan on adding a solar system to recharge my
>> batteries during the week.
>>
>> The boat will primarily be raced/daysailed, and occasionally overnighted,
>> on the weekends. My power draws are an automatic bilge pump, sailing
>> instruments, a chart plotter, and the freshwater tank pressure pump. I have
>> two 79AH Group 24 AGM batteries onboard, one in each bank, wired to a 4 way
>> selector switch.
>>
>> My plan is to install a 50W 12V Monocrystalline Solar Panel connected to
>> a BlueSolar MPPT 75/15 controller, and connect them to the house battery. I
>> am planning on installing a Xantrex Echo Charger between the house battery
>> and the starter battery.
>>
>> Does this system make sense? I've read mixed reviews about the Echo
>> Charger, but I can't find a better way of charging two batteries from a
>> single panel/MPPT controller. Is there a different setup that makes more
>> sense?
>>
>> Thanks and best,
>> Tom
>>
>> ---
>> Snow Goose
>> C&C 35 Mk I
>> City Island, NY
>>
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>> This list is supported by the generous donations of our members. If you
>> wish to make a contribution to offset our costs, please go to:
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>> This list is supported by the generous donations of our members. If you
>> wish to make a contribution to offset our costs, please go to:
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>
> _______________________________________________
>
> This list is supported by the generous donations of our members. If you
> wish to make a contribution to offset our costs, please go to:
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> All Contributions are greatly appreciated!
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_______________________________________________
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make a contribution to offset our costs, please go to:
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