Re: Unsmoothed car battery charger - is it crap?

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.

Reply to
JosephKK
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We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "JosephKK" saying something like:

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.

Reply to
Grimly Curmudgeon

In message , Grimly Curmudgeon writes

|Septics, eh ?

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geoff
Reply to
geoff

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

Reply to
JosephKK

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.

--
Dave Platt                                    AE6EO
Friends of Jade Warrior home page:  http://www.radagast.org/jade-warrior
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Reply to
Dave Platt

ALL lead acid batteries (not gel cells) bubble while charging. That is the normal process. That is why you keep sparks away from charging batteries. It is a normal process.

Reply to
Chieftain of the Carpet Crawle

Where did you get that nonsense? One of the benefits of equalizer charging is that it will form bubbles of gas that helps to stir the electrolyte and mix it to a more uniform concentration.

We deliberately do this to a lot of different lead acid batteries.

What *really* hurts a battery is overheating it or discharging it so low that you reverse one or more cells. But charging to the point of gassing is not a serious problem.

daestrom (former submarine battery-charging electrician)

Reply to
daestrom

I used to rock my batteries several times before a charge session.

Let's have the "placing a lead acid battery on a concrete floor will discharge it" discussion.

Maybe we should submit that one to Myth Busters.

Reply to
Chieftain of the Carpet Crawle

| I used to rock my batteries several times before a charge session. | | Let's have the "placing a lead acid battery on a concrete floor will | discharge it" discussion. | | Maybe we should submit that one to Myth Busters.

I wanna see some batteries explode! Can they get 1000000 amps through it?

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| Phil Howard KA9WGN       | http://linuxhomepage.com/      http://ham.org/ |
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Reply to
phil-news-nospam

Maybe we can get them to go after the world record for size of a Tesla coil.

They'd probably have to have a sub-station put in.

Reply to
Chieftain of the Carpet Crawle

I remember my parents always opening the fillers on the top of the battery to let the gas out. (why I don't know, they vent when you charge them on the car anyway)

Then they got one of those fancy auto vent batteries with the lift up vent cover.. they decided that they needed to lift that when charging it. Came back to a floor covered in battery acid as lifting the strip closed the vents, really intelligent design that.

So gassing can do a lot of harm if the user expects different behaviour to what happens.

>
Reply to
dennis

Gassing doesn't do harm. Dumb users do harm. Just like with guns.

Reply to
Chieftain of the Carpet Crawle

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "JosephKK" saying something like:

Umm.. lemme see. How many years have I been involved with automotive batteries? Many.

How many batteries have I wrecked by overcharging them? None.

How many batteries have I seen bubbling? Quite a few.

Note that I don't particlarly recommend leaving the battery on a charger until it's bubbling vigorously, like a deep-fat frier, but if it happens it happens and so far it's not damaged any flooded lead-acid cells I've had. Anyway, that's why I have them on a timer.

Reply to
Grimly Curmudgeon

The only time I've ever seen a battery damaged by overcharging was when the voltage regulator failed on a friend's car in a way that the output was much higher than it should be, and it boiled almost all the water out.

Reply to
James Sweet

I was very close to that once I reckon, with a motorcycle battery, when I neglected to remove the vent plug before charging. The whole case was bulging ominously by the time I noticed.

--
Roger Hunt
Reply to
Roger Hunt

Every low maintenance wet battery I've seen has a vent to stop this happening. Often with a plastic tube attached to vent the fumes out of harm's way. Genuine SLA have a vent too - but no 'vent plug'

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*TEAMWORK...means never having to take all the blame yourself *

    Dave Plowman        dave@davenoise.co.uk           London SW
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Reply to
Dave Plowman (News)

In article , Dave Plowman (News) writes

This was a small (easy to overcharge and froth) basic liquid lead/acid battery, a Yuasa YB3L, IIRC. All cells breathe to a vent at the side, then a plastic tube downwards. When it is supplied wet, this vent is plugged for obvious reasons, and it is easy to forget to remove it before the initial trickle charge I used to give them.

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Roger Hunt
Reply to
Roger Hunt

the

session

That is not the style, action, or purpose of an equalizing charge. No bubbling is involved in anything i have found on equalizing charging.

Reply to
JosephKK

"JosephKK"

were

the

session

charging=20

and=20

=20

gassing is=20

The bubbling is mainly released hydrogen. This results in an unwanted excess of sulfate ions. You should be able to figure it out from there.

Reply to
JosephKK

Interesting - thanks. I've seen articles posted which assert that the equalizing and de-stratification does involve some amount of gassing... and now that I look, I see other references which either don't mention gassing during equalization charge or which state that a proper equalizing charge should be prolonged, slow, and should definitely _not_ cause gassing.

--
Dave Platt                                    AE6EO
Friends of Jade Warrior home page:  http://www.radagast.org/jade-warrior
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Reply to
Dave Platt

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