Page 1 of 7   1 2 3 > last >>
Bookmark this page: Feed Icon Feed Icon Feed Icon Feed Icon Feed Icon Feed Icon
  •  
  • Subject
  • Author
  • Date
If you were  Registered and logged in, you could reply and use other advanced thread options
Posted by JosephKK on June 9, 2009, 8:03 am

>My car battery is oversized for the car. The battery is a bit old=20
>but usually works fine. The battery is flat (I left the lights=20
>on). =20
>My fancy new modern charger senses a poor battery and only puts in=20
>very little charge.
>I used to use a really old charger to charge this battery=20
>successfully. I opened up the old charger and saw it was only a=20
>transformer and a big rectifier. That's it. No soothing.
>Is this ok for a car battery or is it way too crude?

It is actually better than you might expect. It turns out that for
battery and plating type reactions pulsed DC actually works better in
most cases. It has something to do solution kinetics. And as other
posters have noted, you gotta monitor that old thing, and about 4
hours max per session, preferably not more than 1 to 2 hours per
session.

Posted by Grimly Curmudgeon on June 15, 2009, 9:14 am
We were somewhere around Barstow, on the edge of the desert, when the
saying something like:

> And as other
>posters have noted, you gotta monitor that old thing, and about 4
>hours max per session, preferably not more than 1 to 2 hours per
>session.

That's a perfectly ordinary home-use 4A charger, of which millions were
made. As charging state rose, the current fell and it took ages for the
battery to start bubbling, usually a day or so.
Still best to have it on a timer, I would agree, but 4 hours per session
is nonsense.

Posted by geoff on June 15, 2009, 2:21 pm
>We were somewhere around Barstow, on the edge of the desert, when the
>saying something like:
>> And as other
>>posters have noted, you gotta monitor that old thing, and about 4
>>hours max per session, preferably not more than 1 to 2 hours per
>>session.
>That's a perfectly ordinary home-use 4A charger, of which millions were
>made. As charging state rose, the current fell and it took ages for the
>battery to start bubbling, usually a day or so.
>Still best to have it on a timer, I would agree, but 4 hours per session
>is nonsense.


|Septics, eh ?

--
geoff

Posted by JosephKK on June 18, 2009, 10:35 pm
On Mon, 15 Jun 2009 14:14:29 +0100, Grimly Curmudgeon

>We were somewhere around Barstow, on the edge of the desert, when the
>saying something like:
>> And as other
>>posters have noted, you gotta monitor that old thing, and about 4
>>hours max per session, preferably not more than 1 to 2 hours per
>>session.
>That's a perfectly ordinary home-use 4A charger, of which millions were
>made. As charging state rose, the current fell and it took ages for the
>battery to start bubbling, usually a day or so.
>Still best to have it on a timer, I would agree, but 4 hours per session
>is nonsense.

By the time the battery is visibly bubbling you have damaged
irreparably.

Posted by Dave Platt on June 19, 2009, 12:17 am

>>made. As charging state rose, the current fell and it took ages for the
>>battery to start bubbling, usually a day or so.
>>Still best to have it on a timer, I would agree, but 4 hours per session
>>is nonsense.

>By the time the battery is visibly bubbling you have damaged
>irreparably.

I believe that this depends on the specific battery type.

As I understand it, classic lead-acid flooded storage cells are often
deliberately given a periodic "equalizing charge", at a voltage high
enough to cause electrolysis and bubbling. This mixes up the
electrolyte, reversing the stratification of water and acid which can
occur in these cells. One then adds some water to replace what was
lost in gas form due to the electrolysis. Done properly this doesn't
seem to damage batteries designed for it.

This shouldn't be done to gel cells (or AGM cells, I imagine)... I
believe it *will* damage those.

I'm not sure how tolerant modern "no-maintenance" grid-plate car
batteries are to this sort of overcharge.

--
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

Page 1 of 7   1 2 3 > last >>
  • Subject
  • Date