T-Pain Is On A Boat: Re: [Electric Boats] When good batteries go bad

Friday, July 17, 2009

Re: [Electric Boats] When good batteries go bad

> > > From: Tad G <tad@>
> > > Reply-To: <electricboats@yahoogroups.com>
> > > Date: Thu, 16 Jul 2009 18:00:07 -0400 (EDT)
> > > To: <electricboats@yahoogroups.com>
> > > Subject: Re: [Electric Boats] When good batteries go bad
> > >
> > > One of the reasons to not do that is that you end up with the good battery
> > > charging the bad one, the worse case scenario in terms of losses. As soon as
> > > the charger isn't keeping the bad one topped off the good one will start do to
> > > so, but obviously it won't be able to and they will both loose charge until
> > > they are depleted. --- In electricboats@yahoogroups.com, "aweekdaysailor" <aweekdaysailor@...> wrote:

No. this is a very popular myth. If the "good" one for example loses 1AH per day and the bad one 10AH they will still do that when paralleled together . If two batteries are unequally charged and then they are joined together current will flow between them only until the charge is shared . You can see this most easilly if you connect a large capacity say a 200Ah in parallel with a small one ,say 20AH . the large one does not "swamp" the small one . it is like two buckets of water connected by a pipe .as long as the top of the buckets is the same, water only flows until the level is the same in each bucket ( even different sized buckets). Equivalent in the battery case to settling to the same voltage.

Chris S