Posted by news on March 24, 2009, 1:57 pm
On Tue, 24 Mar 2009 05:29:00 -0700 (PDT), Jim Wilkins
Sears sells one similar to the Schumacher, but it shuts off
automatically on the 2 Amp range. I use the 2 Amp range on smaller
lead-acid batteries ( riding mower). Probably around $0-$0.
Posted by Ulysses on March 24, 2009, 6:18 pm
I have an older Schumacher charger with 2, 10 and 50 Amp ranges, on
10A it shuts of at the selectable "Conventional" or "Maintenance Free"
full charge voltage. IIRC the 2A range is always on so it might be
able to equalize a low cell, but I use a modified charger with a
higher output voltage and a current meter for that.
I don't see the point of paying extra for temperature compensation on
a higher-powered charger. You use them to bring the battery back up so
you can start the vehicle, then it's on it's own alternator. Float
chargers can benefit from it unless their output is low enough that
they won't overcharge. I've seen ~ 100mA suggested as safe for lead-
I have (had) an old Schumaker that sounds just like what you described. It
always shut down when the batteries were only about 80% charged. Over time
this ruined the batteries. Maybe something was wrong with mine but I cannot
recommend it to anyone.
I replaced it with a Vector "Smart Charger", 40 amps max. It worked quite
well until the cooling fan quit. It was replaced under warranty (5 years!)
with a Black & Decker 40 amp smart charger. It worked quite well until the
cooling fan quit. I glued a 12 volt brushless cooling fan onto the outside
of the housing and connect it to the battery when needed (anything over 20
amps). This charger also has an equalize setting, will check the voltage
range of alternators, and has a desulfate function. It will also start a
car with a dead battery. Worth the $0, except for the crappy cooling fan.
Unfortunately it will shut down on old, sulfated batteries before I think it
should so in that case I use my old, cheap 4 amp manual charger.
Posted by Jim Wilkins on March 24, 2009, 11:36 pm
For lead-acid batteries in storage I use the automatic charger for
bulk charge and then go up to the voltage and specific gravity on the
www.batteryfaq.com chart with a cheap Lascar power supply. The voltage
control is too coarse to set for a maximum charge on NiMH or lithiums
but it's fine for lead-acid, or lithiums in storage.
Posted by Martin Riddle on March 23, 2009, 8:07 pm
For a standard auto/marine 12 volt battery the Black&decker or the
Vector chargers are pretty good.
I have the vector VEC1097 and it has all the bells and whistles, handles
all the required charge modes, and even has a de-sulfator.
The B&D looks awfully similar
Your battery should be good shape other wise it will over charge and
destroy it. Thatís one thing I donít like about this charger.
They could improve it by adding battery temperature compensation and