[C320-list] Battery Charger

[Jeff Hare]

Ding.   :)  I think my head just popped.  :)

Jeff

Warren Updike <wupdike at hotmail.com> wrote:

>OK, so, I could be wrong. I have been wrong in the past.  I hate the
>taste of crow; but, not as much as I hate being ignorant.  I'm going to
>call on my friend and mentor Nigel Calder...
>OK, Nigel says (3rd edition) "To be safe, anytime a system is designed
>to hold sustained charge rates above 10%-15% of battery capacity, and
>especially if the target is in the 25% or higher range, the voltage
>regulator... must include temperature compensation...sensing at the
>batteries (not at the regulator.)"
>So what happens is that as a battery's temp rises the voltage at which
>the electrolyte will gas (boil off) drops.  Failure to sense battery
>temps results in boil-off at lower temperatures.  The sensor allows the
>charge regulator to cut back the voltage as battery temp rises.  
>One must consider both charge sources: alternator and shore charger. 
>For most of us, the shore charger is not the issue.  For a single 180AH
>4D, 15% is 27A and 25% is 45A.  For a paralleled 4D bank (360AH,) the
>numbers are 54A and 90A, respectively.  A 40A shore charger is not
>likely to raise these battery temps by very much.  Neither is a stock
>50A alternator.  However, with a high output alternator of 100A or
>more, sustained output of 60A to 80A is possible for a heavily
>discharged bank.  What is sustained?  Nigel doesn't say.  Certainly
>more than a few minutes.
>It's not unusual for temps here in Baltimore to reach 90deg. in July
>and Aug.  With batteries sequestered in an enclosed space battery temps
>can easily rise to 100deg or higher when being charged.  Our house bank
>is 2 parallel 4Ds of nearly 400AH.  When discharged to 50-60%, a
>sustained nominal (unregulated) charge voltage over 14V in absorption
>phase is likely.  The gassing voltage at 100deg is about 14V.
>So, I agree with Jeff, temp sensing and/or a timer will likely prevent
>thermal runaway, however, battery temp sensing where sustained charge
>currents are possible will also prevent excess gassing (overcharging.) 
>Admittedly, for most of us, under conditions experienced most of the
>time, overcharging is not much of an issue.  If your charge sources are
>rated less than 15-20% of your bank capacity you might skip battery
>temperature sensing.  
>Since I've replaced two sets of batteries because of excess gassing,
>when replacing my shore charger I opted for the battery temperature
>sensor device.  Better safe than sorry.  BTW, I have battery temp
>sensing on both shore charger and alternator, as well as alternator
>temp sensing.  
>Nothing about battery management is simple or straight forward.
>Jeff, do chime-in.
>
>Warren & Pattie Updike
>1994 C320 #62 "Warr De Mar"
>
>
>-----Original Message-----
>From: Jeff Hare [mailto:catalina at thehares.com] 
>Sent: Wednesday, October 24, 2012 2:44 PM
>To: C320-List at Catalina320.com
>Subject: Re: [C320-list] Battery Charger
>
>Interesting.  I thought that the battery temp sensor was only really
>useful for preventing thermal runaway when charging or equalizing. 
>Especially when the charger is used in situations where they are
>exposed to hi ambient temps (like engine rooms, etc.).
>
>I wouldn't think it would make any difference at all until the
>batteries start seeing > 100 degree F temps due to charging.
>
>I may have to research this some more myself.
>
>Jeff
>
>Warren Updike <wupdike at hotmail.com> wrote:
>
>>I beg to disagree.  I recommend including the battery temp sensor to 
>>insure proper and full charge.  Cost is nominal and benefit is 
>>demonstrated.
>>
>>Warren & Pattie Updike
>>1994 C320 #62 "Warr De Mar"
>>
>>
>>-----Original Message-----
>>From: JJ Morrison [mailto:sail-ability at sympatico.ca]
>>Sent: Tuesday, October 23, 2012 11:56 AM
>>To: Catalina List
>>Subject: Re: [C320-list] Battery Charger
>>
>>
>>I ditched my Pro Mariner last year for the Xantrex  TrueCharge 2,
>40Amp 
>>and I did the same thing on my previous boat. They work great and have
>
>>good features. I would go for the 40amp as 20 amp is not quite up to 
>>the job of charging the 4D batteries on the C320 especially if the
>boat 
>>is used often and the batteries are frequently discharged. If the boat
>
>>is only used on the weekends and has a few days to recharge then the 
>>20amp will probably suffice. If you are using the boat in warm climes
>I 
>>also would not go for the temperature monitor and use the charger at 
>>the default warm setting.
>>I got a really good deal on the charger from Abe's of Maine, cheaper 
>>than Defender Marine.
>>Cheers
>>JohnM
>> 
>>
>>> Date: Tue, 23 Oct 2012 11:36:09 +0000
>>> From: hcreech at comcast.net
>>> To: C320-List at Catalina320.com
>>> Subject: Re: [C320-list] Battery Charger
>>> 
>>> Donald,
>>> Can't go wrong with the Xantrac 20 or 40. Quiet and efficient , I
>>replaced
>>the noisy and inefficient Pro-Mariner with the Xantrac 20. Very easy
>to 
>>install although some modifications were necessary. Went from an 
>>average battery life of 3 years to over 5 years and counting.
>>> 
>>> Herb Creech
>>> Cloud Chaser 606
>>> 
>>> 
>>> 
>>> 
>>> ----- Original Message -----
>>> From: "Donald Poole" <dpoole15@ gmail .com>
>>> To: c320-list at lists.catalina320.com
>>> Sent: Tuesday, October 23, 2012 6:26:58 AM
>>> Subject: [C320-list] Battery Charger
>>> 
>>> My Newmar HDM 50 battery charger just died. Anyone ever replaced on
>>of
>>> these and can advise as to the current Newmar model or an equal by 
>>> another mfg? I have two banks (12V, 6 cell lead acid).
>>