[C38] House Batteries

[Rich West]

Be careful if you equalize your batteries as some electronics can't stand
the over-voltage condition.  Even if they are turned off, some electronics
are still at risk when equalizing as the on/off switch on most modern
electronics doesn't actually disconnect the power.  For sensitive devices,
you need to turn off the breaker, remove the fuse, or disconnect a wire when
equalizing.

Rich West
Legacy, #360 

-----Original Message-----
From: listserve-bounces at catalina38.org
[mailto:listserve-bounces at catalina38.org] On Behalf Of Les
Sent: Saturday, July 21, 2007 8:40 AM
To: Catalina 38 Listserve
Subject: Re: [C38] House Batteries

Hi, Phil,
	All wetcell batteries tend to develope some sulfation over time.
The battery then has higher internal resistance and will not charge as
deeply thus shows low capacity.  Many marine battery chargers offer an
Equalizing charge capability.  To do this, they run the voltage up a bit
(about 15.6 to 16v typically) and apply about 10% of battery capacity as the
charge current.  This causes the plates to heat a bit, expanding them, and
drops the calcification into the bottom of the battery.  Good deep cycle
batteries, like your Trojans have a deep tray in the bottom to "capture"
this calcification and keep it from shorting the battery plates out.  If you
keep a charger on the batteries all the time, this accelerates the
calcification slightly, but typically once a quarter, equalizing them will
keep their life up.  Also that deep discharge with the 100A shunt will also
heat the plates and drop some of the calcification off, but is not as
effective as the two hour equalizing charge.  Some chargers can even be set
to do this automatically, but I wouldn't recommend it.  The leads and
batteries do get hot, and fire though unlikely, could result.  If the
charger has a temp sensor that helps mitigate the risk.

	If your charger doesn't provide an equalizing charge, perhaps you
can take the batteries to a good battery shop and have them put them on an
equalizing charge while you have a long lunch?  It might help, and couldn't
hurt.  But check your charger's manual.  Many marine chargers are capable of
this and only need to have it triggered somehow.

Regards,
Les H
On Wed, 2007-07-18 at 21:44 +0000, eyriepg at comcast.net wrote:
> Two and a half years ago I installed a pair of  Trojan 6V golf cart 
> batteries in my boat.  The have never been abused but it seems like 
> they discharge significantly quicker than they used to.  I doubt that
> they have been dischared below 12.0 volts more than 5 times.   I
> hauled them out of the boat and had them checked at my battery store.
> The checker put a 100 amp load on them for a few seconds and 
> pronounced them good.  Is this a good test for the capacity of a deep 
> cycle battery?  How do you know when it is time to replace your house 
> batteries?  I am thinking that I should install an amp-hr meter.
>  
> Phil Gay
> C38 094 Que Linda
> Everett, WA
> _______________________________________________
> Listserve mailing list
> Listserve at catalina38.org
> http://catalina38.org/mailman/listinfo/listserve_catalina38.org


_______________________________________________
Listserve mailing list
Listserve at catalina38.org
http://catalina38.org/mailman/listinfo/listserve_catalina38.org