"Ignoramus29935" wrote in
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On 2012-05-12, Jim Wilkins wrote:

"Ignoramus8579" wrote in
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The stacker comes with a weakened battery, and without a battery
charger. The previous owner charger it with a "car charger". I am
wondering, what should one get to charge this one. It has a 12v
Deka battery that weights, perhaps, 300 lbs.
i

My automatic charger fails on older batteries that require
increased
voltage to equalize one or more weak cells. I use a home-made
manual
charger with a current meter and a Variac that efficiently adjusts
output voltage. Sometimes "12V" batteries need as much as 16V-17V
to
fully charge all cells.

jsw



I have a variable voltage source (military battery charger)

http://igor.chudov.com/projects/PP-1...-Power-Supply/

So, what you are suggesting, is kind of like this

1) Charge it at 14.3 volts until current falls off.
2) At the end of the charge, increase the voltage to 16v and charge
some more, like 30 min.

Right?

i

I follow these general rules:
http://batteryuniversity.com/learn/a...d_acid_battery

and the temperature compensation chart he
http://www.batteryfaq.org/

If the cell caps come off I charge until all are bubbling, which may
take 14.8V. Higher voltages force current into weak high-impedance
cells and sometimes restore or "equalize" them, sometimes not. I added
three more years to the life of the dead battery that came with my
tractor that way.

Battery makers don't quite agree on the details but I don't think a
tenth of a volt difference matters much for short-term charging.

What do you think of the skill level the manual assumes for the Army
repairman? That was the sort of equipment I was expected to fix
without ever having seen it before, along with trucks, Teletypes,
modems and IBM card readers.

jsw