[C320-list] New House Batteries

Fri Dec 2 07:23:55 PST 2016

Ah Warren, but you are correct....
This is something that falls into the best 'Best Practices' category as opposed to do this or else...especially for banks with just 2 batteries.

It's not just the resistance of the cables, but internal resistance within the battery cells and it certainly is true that the more batteries in the bank, the larger the resistance. If you look on the Smart Gauge web site, they actually do a good job of showing the math (that pesky Ohms Law again).
Full disclosure, I happen to know that Mainesail wrote that piece for SG if I recall correctly.
The idea is to have the loads/charge come across all the cells as evenly as possible for *optimum* battery performance...

Sent from my iPad

> On Dec 2, 2016, at 9:34 AM, Warren Updike <wupdike at hotmail.com> wrote:
> 
> Well, I stand corrected, or at least better informed. So, the logic is reasonable; but, the value is in question in the typical 320 situation. I'll have to pass this my Maine Sail and see what he says.
> 
> Over the years I have learned a few things about batteries:
> -- like people, no two are the same
> -- a single cell can go dead or short for no apparent reason while the rest look fine
> -- charging is everything: fail to keep them fully charged, charge with old/bad charger, is asking for trouble
> -- treat them as well as you treat your pet; they cost about the same as a trip to the vet
> -- don't swear at them; they don't like to be cursed
> 
> Warren
> 
> -----Original Message-----
> From: Jeff Hare [mailto:Catalina at thehares.com] 
> Sent: Thursday, December 01, 2016 10:05 PM
> To: C320-List at Catalina320.com
> Subject: Re: [C320-list] New House Batteries
> 
> Hi Warren,
> 
> Sorry, not *quite* buying that explanation.  :) :)  I totally get the theory behind it. But the reality is that it doesn't matter IN THIS APPLICATION.
> 
> Drawing from a parallel bank "diagonally"  (ie: 2 parallel batteries with Positive coming off of battery 1 and Negative coming off of battery 2) might have some utility for constant high current situations with undersized cables and a lot of individual batteries, but we are only paralleling 2 batteries with suitably large cables on really short runs, so this really isn't a factor.
> 
> In a large Solar array with 10 or 20 batteries, this is a reasonable wiring choice because of the additive resistance effect of the connectors and the high currents driving inverters.  Think about a dozen batteries in parallel, lined up side by side (all + to + and - to -).  Here it totally makes sense in order to even out that resistance because connecting + and - to the first battery means you could have 10 feet of cable and dozens of connectors to pass through before you get to the last battery.  But even then you'll still have some batteries pulling more than their share just because of slight differences in battery chemistry.
> 
> 2 Batteries in Parallel with properly sized wires and decent connections will draw from each battery proportionally to their capacity and internal resistance.  With the load drawing from the terminals of the first battery will not degrade the first battery more than the second over time. If one of your batteries died in 4 or 5 years it didn't die because of where you connected the load.
> 
> My batteries will be 10 this spring.  They have been hard wired in parallel since they were installed.  The load point was entirely from the aft most battery plates (until last spring when I did some rewiring after the lightning strike).  This is anecdotal but if the theory we're discussing is true, I should have one weak or dead battery and one good one.  Just not the case.
> 
> If you have crappy connections, you'll place a larger load on the battery with the best quality electrical connection regardless of where you tap into the bank.  It's just Ohms law.  That will lead to one battery playing the front person on a bicycle built for 2.
> 
> For typical house loads, there should be a pretty insignificant difference in loading between the batteries because of connector resistance.  There are other chemistry factors that will probably combine to play a bigger role (always assuming you have decent connections).  
> 
> Even if both batteries were installed new at the same time from the same source, they will not be identical.  They'll charge slightly differently and have slightly different internal resistances and overall capacities and they'll contribute differently.
> 
> My suggestion is keep your connections clean and don't sweat a few milliamps.  The Theory is one of precision but unless you consider *all* the factors, you're only fooling yourself.
> 
> That said, you should always go with whatever logic makes you most comfortable.  :)  It's what sailors do!  :)
> 
> Cheers!
> -Jeff Hare
> 
> -----Original Message-----
> From: C320-list [mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of Warren Updike
> Sent: Thursday, December 1, 2016 4:10 PM
> To: C320-List at Catalina320.com
> Subject: Re: [C320-list] New House Batteries
> 
> I can't find the source of the information; but, here is my understanding. Think of it like flows of water. In a parallel connection, if you have the load pos and neg on the same battery #1, then the flow of least resistance is in and out of the same battery #1. As the charge degrades on that battery, makeup current flows from the connections with the other battery #2, to balance the charge across both batteries. This is different than connecting the pos load to battery #1, and the neg load to battery #2, which causes the load to flow smoothly through all 12 cells. 
> 
> The difference between the two banks seems trivial; but, according to what I read, from a reliable source I can't remember, the first example results in a greater load on the cells in battery #1, causing that battery to degrade sooner. We certainly don't want that.
> 
> I welcome any challenges or support for this theory.
> 
> Warren and Pattie Updike
> 1994 C320 "Warr de Mar" #62
> Middle River, Chesapeake Bay
> 
> -----Original Message-----
> From: Scott Thompson [mailto:surprise at thompson87.com]
> Sent: Thursday, December 01, 2016 6:47 AM
> To: C320-List at Catalina320.com
> Subject: Re: [C320-list] New House Batteries
> 
> Warren, the logic of that escapes me. If the batteries are connected in parallel then the positive terminals are tied together as are the negative terminals. Assuming the cables and connections are all good, it shouldn't matter which of the tied terminals also has the connection to loads or charge source.
> 
> Scott Thompson
> 
> 
>> On 11/30/2016 5:07 PM, Warren Updike wrote:
>> Jim, re fact that one batt goes first, here is a thought. If they are connected in parallel, the pos and neg cables should be attached to different batteries. This forces the load to pass through all 12 cells. If you have the original wiring with each battery separate, forget I said this.
>> Warren
>> 
>> -----Original Message-----
>> From: jbrown5093 at yahoo.com [mailto:jbrown5093 at yahoo.com]
>> Sent: Tuesday, November 29, 2016 8:35 AM
>> To: C320-List at Catalina320.com
>> Subject: Re: [C320-list] New House Batteries
>> 
>> Just replaced my second set of flooded 4Ds after 6 years. Interestingly it was battery 2 after 6 years on both sets that went first. I was happy with the flooded cells but the local boat yard (getting to old to muscle this set out) said that flooded cells are no longer considered acceptable by ABYC standards if they are housed in the salon or berths without separate ventilation-probably because of potential problems like Greg's. if true that might be a consideration if you need a survey for insurance or sale purposes in the next few years.
>> 
>> On their recommendation I went to AGM Lifeline batteries. I had the Charles charger that did not support AGMs. Called Charles and they will convert the charger to AGM compatable for $75.  Great people to work with-much like Garhauer.
>> 
>> Jim Brown
>> Desafinado 973
>> 
>> 
>> 
>> Sent from my iPad
>> 
>>> On Nov 29, 2016, at 5:42 AM, Scott Westwood <scottwestwood at bellsouth.net> wrote:
>>> 
>>>  John,
>>> Do you have any pics on where you mounted your solar equip?  That may be our next large purchase.
>>> Thanks,
>>> Scott Westwood scottwestwood at bellsouth.net H (919)-362-8538    C (919)-618-7185
>>> 
>>>      From: John Morrison <sail-ability at sympatico.ca>
>>> To: "C320-List at Catalina320.com" <C320-List at Catalina320.com>
>>> Sent: Monday, November 28, 2016 8:45 PM
>>> Subject: Re: [C320-list] New House Batteries
>>> 
>>> Conventional wisdom of this group has been recommending the deep cycle Interstate battery. I purchased 2 several years ago and they R performing well.  My boat has a 55amp alternator and rather than upgrade it I installed a 185W solar panel. I highly recommend this upgrade haven't plugged into shore pwr in 2 seasons.
>>> JohnM 1999#574
>>> 
>>> Sent from my iPhone
>>> 
>>>> On Nov 28, 2016, at 8:32 PM, Dean Agee <dagee at iserv.net> wrote:
>>>> 
>>>> Our recently purchased 2002 - 320 came with 4 ½ year old batteries 
>>>> which I discovered to be 4D PowerSource Industrial/Tractor Batteries.
>>>> 
>>>> 
>>>> 
>>>> A recent overnight trip convinced me that they are heading towards 
>>>> the end of their life.  Identical replacement batteries are $164 
>>>> each.  The Marine equivalents run around $600-$700.
>>>> 
>>>> 
>>>> 
>>>> Does anyone have thoughts on battery replacement?  I don’t mind 
>>>> spending the extra money – but would like to know what I’m getting for the money.
>>>> 
>>>> 
>>>> 
>>>> Also, in another post, the owner of an early series boat – in the 
>>>> #160s – said that the Catalina supplied alternator was “undersized”.  
>>>> Does anyone know if Catalina upgrade the alternator in later boats?
>>>> 
>>>> 
>>>> Thanks!
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>>> Dean Agee
>>>> 
>>>> 
>>>> 
>>>> AhSeaHola #912
>>>> 
>>> 
>> 
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