Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.1 6/24/83; site alice.UUCP
Path: utzoo!linus!decvax!harpo!eagle!alice!wookie
From: wookie@alice.UUCP
Newsgroups: net.auto,net.rec.boat
Subject: Re: Marine batteries
Message-ID: <2065@alice.UUCP>
Date: Mon, 25-Jul-83 16:54:56 EDT
Article-I.D.: alice.2065
Posted: Mon Jul 25 16:54:56 1983
Date-Received: Mon, 25-Jul-83 23:44:38 EDT
References: <339@hou5f.UUCP>
Organization: Bell Labs, Murray Hill
Lines: 29

I think we had better find a battery expert here at Murray Hill for this
battery question.  It is my understanding that a lead acid battery is best
kept fully charged at all times.  From time to time if it is unused it
should be trickle charged at a very low current (<1 amp?) every couple of
weeks.  A lead acid battery left at some discharged level will build up
hard sulfate on the plates which is not easily converted back to lead
peroxide and lead and thus the capacity is reduced.

My experience with nickle cadmium batteries however indicates that they are
best stored in a discharged state (this info came directly from engineers
at General Electric) and that they should be fully cycled from complete
charge to complete discharge.  Ni-cads exhibit a memory for the amount they
are used.  If you use you battery grass trimmers for 20 minutes and then
leave it on the charger the rest of the week, eventually they will only
run for 20 minutes and then die completely.  They also tend to crystalize
if left on the charger all the time and will not work at all unless you
zap them with a very high current for a short period of time (seconds)
to break down the crystals.  WARNING: This is a dangerous practice as
the battery can explode throwing potassium hydroxide all over the place!

Anyway in conclusion from what I have read it is best to keep a lead acid
battery fully charged at all times and the less you cycle it the longer it
will last.  A Ni-cad should be fully and deeply cycled or stored in a
discharged state.

Any experts out there on this subject??

					Keith Bauer
					White Tiger Racing