[C320-list] Battery Isolation
Kirk McCullough
kirk.mccullough at telus.net
Sat Apr 25 10:59:51 PDT 2009
He did mention something but it didn't stick with me. At the time it seemed
a little bit strange to me that the wings nuts had to go. I think it had
something to do with the potential for them to work loose, maybe if the
wings get caught on something. It was something like that. Hex nuts maybe
make a little more sense.
Kirk
#124
-----Original Message-----
From: c320-list-bounces at lists.catalina320.com
[mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of
bruceheyman at cox.net
Sent: 23 April 2009 16:12
To: C320-List at Catalina320.com
Subject: Re: [C320-list] Battery Isolation
Kirk,
Did he say what the issue with the wing nuts are?
Bruce
Somerset 671 SoCal
Sent via BlackBerry by AT&T
-----Original Message-----
From: "Kirk McCullough" <kirk.mccullough at telus.net>
Date: Thu, 23 Apr 2009 15:15:23
To: <C320-List at Catalina320.com>
Subject: Re: [C320-list] Battery Isolation
Warren
The only thing the surveyor noted in his report regarding the DC systems
were the wing nuts used on the battery posts. Wing nuts are no longer
acceptable under the newer code. He was happy with the rest including the
wiring of the house and starter banks.
I don't mind the brain exercise I get when deciding on which bank to
charge.... should I do the house bank or maybe I should do the starting
bank? The link 20 system tells me the state of each and simplifies the
decision, although as I mentioned below, the starting battery is normally
fully charged, since it gets little use.
The only other thing that taxes my mind to these levels is when to get into
the dinghy and check the crab pots. :)
Kirk
#124
-----Original Message-----
From: c320-list-bounces at lists.catalina320.com
[mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of warren updike
Sent: 22 April 2009 14:40
To: C320-List at Catalina320.com
Subject: Re: [C320-list] Battery Isolation
I believe one of the recommended approaches cited on the C320 web site is
just exactly that: to connect the starting bank on 2, and the house bank on
1. I can't imagine a surveyor having an issue with any such approach as long
as the proper sized wires are used, solid connections, conduit, fusing, etc.
The difference is merely one of ease and convenience. With my dual circuit
switch my power is either on or off. Shore charger and alternator charge the
house bank and the combiner manages the starting bank. I don't ever think
about it. Turn it on when I arrive. Turn it off when I leave. No thinking
about whether to switch between 1 or 2 or Both as I transition from power to
sail to dockside. On or Off. I can handle that.
Incidentally, I also installed a battery monitor. Acts like a fuel gage to
let me know how much capacity remains in the house bank and sounds an alarm
should it get too low. It's a very sophisticated device; but, it simplifies
the power management. It's either at 100%, 50% or somewhere in between.
I don't like to think too much when I'm having fun. On or Off. No thought.
Warren & Pattie Updike
Catalina 320, #62, "Warr De Mar"
Middle River, Chesapeake Bay
-----Original Message-----
From: Jeff Church [mailto:jc387 at att.net]
Sent: Tuesday, April 21, 2009 4:00 PM
To: C320-List at Catalina320.com
Subject: Re: [C320-list] Battery Isolation
Kirk,
I'm not sure. I'd have to ask that picky surveyor.
I guess the question arises in my mind because everyone I asked
suggested that I use either a combiner or isolator. No one even hinted
that I should just use the switch to control charging. I'm not saying
that your solution is wrong, I just wonder what the "experts" or a
surveyor would have to say about it.
JeffC
Kirk McCullough wrote:
> Jeff
>
> I just had a survey in February for insurance reasons. The surveyor
checked
> out all electrics mainly from a safety angle and gave me a clean report.
>
> What would be the concern with this arrangement?
>
> Kirk
> #124
>
> -----Original Message-----
> From: c320-list-bounces at lists.catalina320.com
> [mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of Jeff Church
> Sent: 18 April 2009 18:41
> To: C320-List at Catalina320.com
> Subject: Re: [C320-list] Battery Isolation
>
>
> Kirk,
>
> Catalina installs the optional starting battery that way on the 387.
> They just parallel the house batteries and connect the starting battery
> to #2 on the battery switch, without using an isolator or combiner. I'm
> not sure what a picky surveyor would say about that.
>
> JeffC
>
>
> Kirk McCullough wrote:
>
>> Is it not just about as easy to leave the house and starting batteries
>> un-combined or un-isolated and just select which one to charge with
>> the 1-2-both switch? That's what I do and the starting battery is
>> always good to go. I don't use it for anything but starting and even
>> then if I happen to be on house while at anchor I often just use them
>> to start the engine.
>>
>> I didn't see or maybe didn't properly understand the benefit of the
>> ACR when it was explained to me recently, so I just bought a new Blue
>> Sea 1-2-Both switch when I bought new 4D deep cycle batteries last
>> fall, just to be sure I wasn't getting any leakage across my old
>> original Guest 1-2-Both I replaced it. All is good.
>>
>> Kirk
>> #124
>>
>> ----- Original Message ----- From: "Jeff Church" <jc387 at att.net>
>> To: <C320-List at Catalina320.com>
>> Sent: Friday, April 17, 2009 7:35 PM
>> Subject: Re: [C320-list] Battery Isolation
>>
>>
>>
>>> Bob,
>>>
>>> Me too. That's why I thought as soon as the combiner closes, current
>>> from both the charger and starting battery would flow through the
>>> house batteries until the resistance of the house bank increased.
>>>
>>> What would happen if there was a shorted cell in the house bank? With
>>> a combiner couldn't the starting battery discharge thru the shorted
>>> house battery?
>>>
>>> I was also told by the guys at Charles that since the discharged
>>> house batteries present the least resistance, most of the bulk and
>>> absorption charge will flow thru them, so the smaller starting
>>> battery will not over charge.
>>>
>>> Jeff
>>>
>>>
>>> Robert Seastream wrote:
>>>
>>>> I thought a discharged battery has an extremely low resistance, thus
>>>> presenting a near short to any charging source.
>>>>
>>>> Bob Seastream
>>>>
>>>>
>>>> On Apr 17, 2009, at 10:00 AM, <crashley at gte.net> wrote:
>>>>
>>>>
>>>>> At the risk of offending Orlando again, I'll take a crack at this.
>>>>> When you
>>>>> turn the charger on into an open circuited or discharged house
>>>>> battery, it
>>>>> takes a little while (several seconds) for the battery voltage to
>>>>> climb up
>>>>> to the initial charging voltage which should be about 14.4V. This
>>>>> delay is
>>>>> because the battery looks like a large capacitor. The ACR has a
>>>>> time delay
>>>>> in it so when it senses that the house battery voltage is 13.5V (or
>>>>> higher)
>>>>> the timer starts and 30 seconds or so later the relay closes. At
>>>>> this point
>>>>> the house battery is at 14.4V and the starting battery is at 12.7V
>>>>> (open
>>>>> circuit voltage) so it will start charging too. I think the only
>>>>> possible
>>>>> issue here is that if the house battery is a lot larger than the
>>>>> starter
>>>>> battery, which is normally the case, the starter battery will see a
>>>>> longer
>>>>> "absorb" charge time than it needs, but I don't think this is a big
>>>>> problem.
>>>>>
>>>>> Long live space junk!
>>>>>
>>>>> CR Ashley
>>>>> Rosebud C320 Hull #882
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> -----Original Message-----
>>>>> From: c320-list-bounces at lists.catalina320.com
>>>>> [mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of Jeff
>>>>> Church
>>>>> Sent: Wednesday, April 15, 2009 10:57 AM
>>>>> To: C320-List at Catalina320.com
>>>>> Subject: Re: [C320-list] Battery Isolation
>>>>>
>>>>> Chris,
>>>>>
>>>>> Like I said, maybe I didn't totally understand what the guys at
>>>>> Charles and
>>>>> PS (2 independent sources) told me.
>>>>>
>>>>> Why wouldn't the ACR sense 14 volts, or more, the moment that the
>>>>> charger
>>>>> switches on? My battery monitor does. I know that there will be
>>>>> some voltage
>>>>> drop due to the discharged house, but the charger output is
>>>>> 15 or 16 volts initially.
>>>>> .
>>>>> Jeff
>>>>>
>>>>>
>>>>>
>>>>> crashley at gte.net wrote:
>>>>>
>>>>>> I disagree. It doesn't surprise me that the guys who make the
>>>>>> expensive MOSFET devices will tell you what they did. The ACR will
>>>>>> not
>>>>>> close until the battery being charged reaches 13.5V. The starter
>>>>>> battery should be sitting at around 12.7V before that so it will not
>>>>>> discharge into the higher voltage battery, it will actually start
>>>>>> receiving charge current as well. I agree that the ACR will allow
>>>>>> current to go in either direction, but in this case it should not.
>>>>>> The
>>>>>> only time this might occur is if the charging source goes away in
>>>>>> which case the ACR will open when the house battery drops to
>>>>>> 12.7V, so
>>>>>> it should not allow the starter battery to discharge too much into
>>>>>> the
>>>>>>
>>>>> house battery since 12.7V is a fully charged state for lead acid
>>>>> batteries.
>>>>>
>>>>>> PS: I am an EE and have been designing battery chargers and
>>>>>> dischargers for spacecraft for 28 years. Talk about $$$$!
>>>>>>
>>>>>> CR Ashley
>>>>>> Rosebud C320 Hull #882
>>>>>>
>>>>>>
>>>>>> -----Original Message-----
>>>>>> From: c320-list-bounces at lists.catalina320.com
>>>>>> [mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of Jeff
>>>>>> Church
>>>>>> Sent: Tuesday, April 14, 2009 10:53 PM
>>>>>> To: C320-List at Catalina320.com
>>>>>> Subject: Re: [C320-list] Battery Isolation
>>>>>>
>>>>>> When I was designing my setup I spoke at length to several engineers.
>>>>>> The techs at Charles and Perfect Switch (PS makes MOSFET isolators
>>>>>> ($$$$) for the military and NASA) told me about this particular
>>>>>> problem.
>>>>>>
>>>>>> My understanding is that when the charger comes ON, the ACR senses
>>>>>> the
>>>>>> voltage and the switch closes. At that point current flows from any
>>>>>> available source towards the path of least resistance. In this case
>>>>>> the house batteries are the path of least resistance and current will
>>>>>> flow from both the charger and the starting battery to the house
>>>>>> batteries until the resistance in the house and starting batteries
>>>>>>
>>>>> equalizes.
>>>>>
>>>>>> An isolator does not allow any current to pass from one battery bank
>>>>>> to the other.
>>>>>>
>>>>>> I'm not an EE so maybe I got it wrong.
>>>>>>
>>>>>> JeffC
>>>>>>
>>>>>>
>>>>>>
>>>>>> crashley at gte.net wrote:
>>>>>>
>>>>>>
>>>>>>> JeffC,
>>>>>>>
>>>>>>> The Blue Sea Systems battery combiner relay (ACR 7600) has a voltage
>>>>>>> sensor so it will not close until the house battery is being charged
>>>>>>> at 13.5V so the starter battery should never discharge into the
>>>>>>> house
>>>>>>>
>>>>>>>
>>>>>> battery.
>>>>>>
>>>>>>
>>>>>>> CR Ashley
>>>>>>> Rosebud C320 Hull #882
>>>>>>>
>>>>>>>
>>>>>>> -----Original Message-----
>>>>>>> From: c320-list-bounces at lists.catalina320.com
>>>>>>> [mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of Jeff
>>>>>>> Church
>>>>>>> Sent: Wednesday, April 08, 2009 5:59 PM
>>>>>>> To: C320-List at Catalina320.com
>>>>>>> Subject: Re: [C320-list] Battery Isolation
>>>>>>>
>>>>>>> Good info. I looked all over for a Schottky diode isolator and
>>>>>>> didn't
>>>>>>> find out that Guest made one. It also didn't occur to me that
>>>>>>> relay-type devices could create RF noise. I just found the Guest
>>>>>>> unit
>>>>>>> (#2530) at Pyacht.com for about $140.
>>>>>>>
>>>>>>> I recently installed a Sure Power Schottky-diode isolator when I
>>>>>>> installed a starting battery on my 387. According to several
>>>>>>> sources,
>>>>>>> using an isolator is a better approach than using any of the
>>>>>>> combiners or other relay-type devices. The biggest problem with a
>>>>>>> combiner/relay is that when the charging device initially starts and
>>>>>>> the combiner closes, the depleted house bank can immediately draw a
>>>>>>> lot of current from the starting battery. Some of the devices like
>>>>>>> the Echo Charger might not operate that way, but you should check on
>>>>>>> that before buying one. The advantage of the combiner is that it is
>>>>>>> easier to install and
>>>>>>>
>>>>>>>
>>>>>> less wire ($$) is required.
>>>>>>
>>>>>>
>>>>>>> In order to install an isolator you will need to remove the wire
>>>>>>> that
>>>>>>> connects the alternator to the starter motor, and run a #6 wire from
>>>>>>> the alternator to the input terminal on the isolator. Then from the
>>>>>>> #1 and
>>>>>>> #2 output terminals on the isolator you run wires to the battery
>>>>>>> switch
>>>>>>> #1 and #2 terminals, or directly to the house and starting
>>>>>>> batteries.
>>>>>>>
>>>>>>> Good luck.
>>>>>>>
>>>>>>> JeffC
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> jelliott at landspring.net wrote:
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>> I'm learning more... These are relay-based devices; Blue Sea tech
>>>>>>>> support says they may induce RF noise if installed at the panel vs.
>>>>>>>> at the battery (not desirable in my case). Have you experienced
>>>>>>>> this?
>>>>>>>>
>>>>>>>> The Guest isolators use Schottkey diodes, which induce a load (and
>>>>>>>> corresponding heat), but don't suffer the potential RF problem.
>>>>>>>>
>>>>>>>> As usual, there is a tradeoff...
>>>>>>>>
>>>>>>>> Julian
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>> The Yandina is the one I used (mine is a WM re-label of this
>>>>>>>>> product.) It's as simple as described. The Blue Seas Relay will
>>>>>>>>> definitely do the trick as well...
>>>>>>>>>
>>>>>>>>> Regards,
>>>>>>>>>
>>>>>>>>> Jon Vez
>>>>>>>>> Solstice #582
>>>>>>>>>
>>>>>>>>> -----Original Message-----
>>>>>>>>> From: c320-list-bounces at lists.catalina320.com
>>>>>>>>> [mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of
>>>>>>>>> jelliott at landspring.net
>>>>>>>>> Sent: Wednesday, April 08, 2009 4:09 PM
>>>>>>>>> To: C320-List at Catalina320.com
>>>>>>>>> Subject: Re: [C320-list] Battery Isolation
>>>>>>>>>
>>>>>>>>> John,
>>>>>>>>>
>>>>>>>>> I see WM has a Blue Sea Systems Starting Isolation Charging Relay
>>>>>>>>> which seems to do the trick. Is that what you installed?
>>>>>>>>>
>>>>>>>>> Also seen similar items from Guest and from a company called
>>>>>>>>> Yandina (http://www.yandina.com/NewCatalog.htm).
>>>>>>>>>
>>>>>>>>> Looks like this fits the bill with a fairly straightforward
>>>>>>>>>
>>>>>>>>>
>>>>>> installation.
>>>>>>
>>>>>>
>>>>>>>>> Almost too simple to be real...
>>>>>>>>>
>>>>>>>>> Julian
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>> Julian,
>>>>>>>>>>
>>>>>>>>>> I have the exact setup you describe. I used a battery combiner
>>>>>>>>>> from West Marine. It's a simple device that you simply wire to
>>>>>>>>>> each pole on the back of your current switch--one wire to the '1'
>>>>>>>>>> and the other to the '2'.
>>>>>>>>>> It's
>>>>>>>>>> about the size of a match box and takes a couple of minutes to
>>>>>>>>>>
>>>>> install.
>>>>>
>>>>>>>>>> It
>>>>>>>>>> will combine the batteries when motoring via the alternator and
>>>>>>>>>> isolate them when not receiving a charge. Is the 'easy' solution
>>>>>>>>>> to this problem....
>>>>>>>>>>
>>>>>>>>>> Regards,
>>>>>>>>>>
>>>>>>>>>> Jon Vez
>>>>>>>>>> Solstice #582
>>>>>>>>>>
>>>>>>>>>> -----Original Message-----
>>>>>>>>>> From: c320-list-bounces at lists.catalina320.com
>>>>>>>>>> [mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of
>>>>>>>>>> jelliott at landspring.net
>>>>>>>>>> Sent: Wednesday, April 08, 2009 10:59 AM
>>>>>>>>>> To: C320-List at catalina320.com
>>>>>>>>>> Subject: [C320-list] Battery Isolation
>>>>>>>>>>
>>>>>>>>>> I am in the process of modifying my electrical system, and am
>>>>>>>>>> curious as to how others electrically isolate the house bank from
>>>>>>>>>> the starting battery.
>>>>>>>>>>
>>>>>>>>>> I have two 4D's under the settee paralleled as my house bank, and
>>>>>>>>>> a separate starting battery located in the port lazarrette.
>>>>>>>>>> Both are
>>>>>>>>>> connected to independent channels of a Xantrax Truecharge
>>>>>>>>>> 20. The
>>>>>>>>>> house
>>>>>>>>>> bank is monitored with a Link 10.
>>>>>>>>>>
>>>>>>>>>> The banks are still not electrically isolated; I assume this is a
>>>>>>>>>> result of a common connection to the alternator? How do others
>>>>>>>>>> handled
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>> this?
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>>> I
>>>>>>>>>> understand there are battery isolators that do this? Any advice
>>>>>>>>>> on how to "break" this return circuit (if that's the cause) would
>>>>>>>>>> be appreciated.
>>>>>>>>>> I
>>>>>>>>>> am not very interested in adding a second switch which I know
>>>>>>>>>> some
>>>>>>>>>> have done.
>>>>>>>>>>
>>>>>>>>>> Thanks,
>>>>>>>>>>
>>>>>>>>>> Julian
>>>>>>>>>> Polaris #340
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>
>>
>
>
>
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