El 11-05-13 12:47, Wimpie escribió:
El 10-05-13 20:30, Tom escribió:

Hello Tom,

Hi Wim
THanks for the response

Yes, great, I will make the measurement on the battery after one hour
of charging (while charging it) at 10amps to see if it measures
greater than 14.8 volts. That may answer my concern.

If it remains under the 14.8v mark should I just keep it charging?

Unless you always need a fully charged battery always, I would not
leave it on the charger, as even at 14.8V there will be some gassing.
The 14.8V is an average value. The exact value for long time charge
maintenance is temperature dependent (high temperature needs lower
voltage, and may vary a bit per battery type). Some batteries I had
stated 14.4V at room temperature.

You may contact the manufacturer regarding the optimum maintenance
charge voltage.

Using a low maximum charge voltage (for example 14.2V) results in
longer time to reach 100%, or you don't reach 100% state of charge at
all.


My
charger is the automatic style that shuts off when it knows the
battery is fully charged. It has the meter on the front and always
starts off near the red then goes through the yellow part of the meter
then when in the green part of the meter it shuts off and the green
light comes on. If left like this the charger will cycle back on after
a while for very short time then off then on, etc etc, does that mean
it is losing its charge just sitting there? Is that ok or the sign of
a dead or dying battery? Recently it just doesn't shut off and stays
charging. I will measure its voltage at this stage.

I will also measure to see if it is holding the voltage after a few
days of nothing. I have a digital volt meter and can measure that
easily.

Thanks

Tom

http://www.energymatters.com.au/rene...-discharge.php

shows state of charge versus open circuit voltage for various lead
batteries.

You may know that if you don't use them, store your batteries at low
temperature (reduces self-discharge, high humidity is fine) and check
the open circuit voltage every few months. That gives you an idea of
how fast they self-dicharge. For Batteries I don't use frequently I
recharge them when state of charge will drop below 50..60% (when they
drop below 12.3V I recharge them).



Hello Tom,

Some charge voltage numbers that I used in the past for standby
charger design (I don't remember the source). This means the battery
is on the charger every day, year after year.
2.26 to 2.31/cell at 20 degr. C, Correct with -2mV/K battery
temperature.

for a 12V battery: 13.56V to 13.86V

I do remember that some batteries didn't reach 100% charge, but for
many standby use applications, service life is more important then
100% state of charge.

For overnight charging (if you want a 100% charged battery for sure in
short time):
2.43 to 2.53/cell at 20 degr. C

for a 12V battery: 14.58V to 15.18V
When you apply such a voltage to the battery, the battery will bubble
(as you noticed) and the battery will lose water and service life.



--
Wim
PA3DJS
www.tetech.nl
Please remove abc first in case of PM