"Too_Many_Tools" wrote in message
...
On Oct 12, 5:43 am, "RogerN" wrote:
"Too_Many_Tools" wrote in message

...
On Oct 11, 9:52 pm, "RogerN" wrote:
Snip

I've also been disappointed with some of the smart chargers and that is
at
least part of the reason for my post here, thought maybe someone here
found
one to recommend. I'm not sure I understand the difficulty a "Smart"
charger would have with batteries. Seems my auto voltage regulators keep
my
batteries happy for years on the car I drive daily. So, maybe if I had a
charger that automatically started charging when the power was on, I
could
set a time to charge the battery for maybe an hour a day, to simulate
driving the car an hour a day.

RogerN

/
/
/Smart chargers are based on a chip that have the lead acid charge/
/decay curves telling it how to act. I suspect it monitors the voltage
/of the battery and if that info is faulty then the charger works
/erractically.
/
/I too am a believer in settng chargers up on a timer.
/
/How long to charge? Good question. I just do it a hour a day with 2
/amp chargers and it seems to work. YMMV
/
/TMT

That gives me an idea, if I use a 2 amp charger that starts when
connected,
wired the output through relays and use a spare PLC, I can use one charger
and automatically switch it to each battery for 1 hour a day. I can
separate the long runs and run 120VAC to an on board charger.

RogerN
/
/Good idea.
/
/I would just avoid running extra long leads on the low voltage side
/whenever possible...it is just too easy for voltage loss to cause you
/problems especially now with smart chargers monitoring the battery's
/voltage.

Some of the chargers description described as charging and then monitoring
the voltage, when it falls below a certain point it charges again. This had
me thinking that it monitors voltage with almost no current flow. I'd guess
it also monitors voltage during charge with current flow. I thought if I
were brewing my own, I would use shielded 4 conductor, 2 wires for charge
and 2 others for measuring voltage.

/I have found that I need a "dumb" charger to start batteries who have
/been seriously discharged and then allowing the smart charger to
/finish...again that little chip in the smart charger being a bit too
/"smart".

Occasionaly I have to use a good battery in parallel with the discharged
battery to get my "smart" charger to work.

/Idealy you should monitor your batteries with a hydrometer to
/determine the acid/water ratio to know when you are charging at the
/optimal rate and time.
/
/TMT

I would think that would be the best way to get the ultimate charge without
overcharging.

I've played with an adjustable regulator circuit in Electronics Workbench
simulator. I used the typical voltage divider circuit to set the open
circuit voltage and used an inline resistor so that the voltage goes down as
the current goes up. I got an open circuit voltage of 14.201V, .19A at 14V,
2A at 13V.

RogerN