[Rhodes22-list] Batteries

Bob Keller r22yankeeclipper at hotmail.com
Wed Feb 1 22:56:53 EST 2006


Bill,
Forgot to mention that I do have a voltage meter for the batteries.  They 
will show a full charge, but drain much quicker when the batteries are aged.
Bob K


>From: Bill Effros <bill at effros.com>
>Reply-To: The Rhodes 22 mail list <rhodes22-list at rhodes22.org>
>To: The Rhodes 22 mail list <rhodes22-list at rhodes22.org>
>Subject: Re: [Rhodes22-list] Batteries
>Date: Tue, 31 Jan 2006 23:03:44 -0500
>
>Bob,
>
>Yes, this makes perfect sense, and it is easy to understand why it would 
>drain the batteries.
>
>I don't have an autopilot installed yet (I bought it 2 or 3 years ago, but 
>haven't gotten around to installing...) but I would guess that it is the 
>big factor.
>
>The notion of "Amp Hours" works fine if you're not really using your 
>batteries all that much, but it's a distortion in your case.  I'll try to 
>find something on it, but the underlying information is this:
>
>Let's say your batteries each are rated at 125 amp hours, for a total (you 
>would think) of 250 amp hours of use.  If all you attached to the batteries 
>was one of my LED lights, which I will say has a rating of one amp-hour, 
>you would expect that light to burn for 250 hours before the batteries were 
>both "dead" as you used that term in your original posting.
>
>In fact, that light might actually burn continuously for over 1000 hours, 
>and after the batteries seemed "dead" they might subsequently be able to 
>light the light some more without ever being externally recharged.
>
>On the other hand, if you put your 2 batteries into your car on a cold day 
>and cranked your starter motor which we will say has a draw of 25 amps per 
>hour, you would expect that starter motor to be able to crank for 10 solid 
>hours before the batteries were "dead".  But it won't.  Chances are the 
>batteries will be really "dead" in less than an hour.
>
>The available power in the battery varies with the speed it is pulled out 
>of the battery bank, and so is the ability of the batteries to regenerate.
>
>The e-meters will tell you how much time you have left in the battery at 
>varying rates of discharge which it learns over time as you charge and 
>discharge the batteries, and as they age.
>
>You may initially set it for 250 amp hours, and over time it will tell you 
>that even fully charged, those batteries have less power that they did when 
>new, and exactly how much power remains available at all times.
>
>It is interesting stuff to learn, and, in your case, probably would have 
>told you to replace your batteries after 3 years, whereas mine, which 
>withstood only a gradual draw, were perfectly adequate for 6 years.
>
>With regard to identical batteries, in your case I would surely recommend 
>it, while in mine it makes little difference.  I doubt the super sizing 
>will make much difference at all.  They will still need replacement after 3 
>years, and during that 3 year period they will probably never flat line, 
>even with the standard batteries.
>
>The meter is the trick.  If you know what's happening inside those 
>batteries you'll never be surprised, and you won't have to oversize in the 
>hope it will make a difference.  What you will save in more expensive 
>batteries and peace of mind will offset the (high) cost of the meter.  It 
>is easy to set up.
>
>Bill Effros
>
>
>
>Bob Keller wrote:
>
>>The batteries are 4 years old so they have to be replaced. They are 
>>standard Interstate group 27 batteries which I will super-size to a 29 or 
>>31 when I replace them in March.  An important point with batteries 
>>connected in parallel as mine are is that I make sure the batteries are 
>>identical in size and replace them at the same time.
>>
>>Mine are not actually dead now, but they don't hold a charge and will run 
>>out after several hours of sailing using autopilot, stereo, depth finder, 
>>knotmeter & wind instrument.  Can you believe that would drain the 
>>batteries?
>>Bob K
>>
>>
>>>From: Bill Effros <bill at effros.com>
>>>Reply-To: The Rhodes 22 mail list <rhodes22-list at rhodes22.org>
>>>To: The Rhodes 22 mail list <rhodes22-list at rhodes22.org>
>>>Subject: [Rhodes22-list] Batteries
>>>Date: Mon, 30 Jan 2006 21:32:36 -0500
>>>
>>>Bob,
>>>
>>>How did you manage to do this?  Was one of the batteries damaged?  Did 
>>>you fail to add water to wet cells?  Wet cells?  Gel?  AGM?
>>>
>>>Link 10. -- Now Xantrex e-meter and this will never happen.  No excuse 
>>>for it.
>>>
>>>I have 2 batteries connected, no switch, solar, elec start motor -- I 
>>>have never, ever, needed a shore power charge, my batteries last for 6 
>>>years, I leave them in the boat summer and winter...been down this road 
>>>before.
>>>
>>>KISS with a meter -- the meter tells you of a problem coming 6 months 
>>>before it happens --BTW, just to add fuel to another fire, I don't 
>>>replace both batteries at the same time, I mix types, (one is AGM, one is 
>>>Wet) I prefer wet cells all round -- I know what the magazines and west 
>>>adviser say, I know the science behind it, but I'm a curious guy so I try 
>>>it out in my boat when it's not critical and what I find is that on our 
>>>boats with their minimal power needs it's really tough to drain well 
>>>maintained batteries.
>>>
>>>How did you do it?
>>>
>>>Bill Effros
>>>
>>>Bob Keller wrote:
>>>
>>>>I paid (overpaid?) someone to run cables from my electric start motor to 
>>>>the battery under the port settee.  Then we connected both batteries 
>>>>together and so now I charge both batteries with the motor, and two 
>>>>solar panels and even have an electric charger on board if needed.  
>>>>Guess what?  My batteries are currently dead...
>>>>
>>>>Anyway, I vote with Chris who used jumper cables.  The cables in my boat 
>>>>are big-but I don't know the size.  Lots of useful information here, 
>>>>isn't there?
>>>>Bob K
>>>>
>>>>
>>>>>From: Michel Meltzer <mjm at michaelmeltzer.com>
>>>>>Reply-To: The Rhodes 22 mail list <rhodes22-list at rhodes22.org>
>>>>>To: 'The Rhodes 22 mail list' <rhodes22-list at rhodes22.org>
>>>>>Subject: RE: [Rhodes22-list] 12 volt wire gauge from OB to Cabin 
>>>>>(10'maxassumed)
>>>>>Date: Sun, 29 Jan 2006 13:33:35 -0500
>>>>>
>>>>>Been their before on the sizing, IIRC my run from the front(under the
>>>>>step) to the mount lungs was 16 feet each way(32 total) and the motor
>>>>>had #8 wire leads for 8 feet each way(meant to go on the battery) for
>>>>>another 16 feet worth, it a good trip,, because the batty is far away
>>>>>the voltage regulator also gets effected on charging(i.e. the voltage
>>>>>drop), after everything was said and done, #4 came out right and I used
>>>>>#2 just to improve performance and all but handle a dead short. NOW #2
>>>>>could be a PITA for getting it passed the bulkhead but I did not have
>>>>>that issue. Using the breaker is just cheap insurance.
>>>>>
>>>>>-MJM
>>>>>
>>>>> > -----Original Message-----
>>>>> > From: rhodes22-list-bounces at rhodes22.org [mailto:rhodes22-list-
>>>>> > bounces at rhodes22.org] On Behalf Of R22RumRunner at aol.com
>>>>> > Sent: Sunday, January 29, 2006 12:47 PM
>>>>> > To: rhodes22-list at rhodes22.org
>>>>> > Subject: Re: [Rhodes22-list] 12 volt wire gauge from OB to Cabin 
>>>>>(10'
>>>>> > maxassumed)
>>>>> >
>>>>> > Bill,
>>>>> > Not necessarily true. Having to large a wire makes for difficult
>>>>>handling,
>>>>> > but also is a waste of money. Sizing the wire to the required 
>>>>>project
>>>>>is
>>>>> > always
>>>>> >  the best way to go.
>>>>> >
>>>>> > Rummy
>>>>> > __________________________________________________
>>>>> > Use Rhodes22-list at rhodes22.org, Help? www.rhodes22.org/list
>>>>>
>>>>>__________________________________________________
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>>>>
>>>>
>>>>
>>>>
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>>
>>
>>
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