Warm day, rain ended, tested charger.
No pen or paper, voltages are approximate.
On 2 amp setting was about 11.5 volts but after connnected to the
battery for a couple minutes, and then disconnected, up to 12.6 or
13.6, I forget.
After reconnected, up to 14.2. !!!! It works.
2 amp setting charges at about 3 amps, 10 amp setting charges at about
twice that, 6 amps.
Now, no reason to take apart the charger, but peeking in the slots
does show what is probably a circuit board about the size of half a
Nabisco graham cracker. It's covered by a sheet of metal. I assumed
no slots on the other side but I should have looked. So I don't know
what was in there.
This one was made in January 1997, but the same model, 87102, but with
a suffix C, is still sold! No indication on the charger or in the
Lowes, Home Depot, Amazon advertising or even the maker's website that
is any smarter than stupid, even though it looks like it must be (but
*). In fact they make a point to call it "manual".
"Easy-to-use manual controls."
*In the 10amp setting " The meter will
read up to 15 amps and taper down to 6 or 7 as the
battery reaches full charge. When the battery is fully
charged you must shut off the charger within 2 hours or
overcharging will occur." So it's semi-smart. (In the 6volt setting,
it doesn't taper down) It doesn't have a warning l ike this for the
2 amp setting!
The model with the next higher number, on 10 amps, says it tapers down
to 1 amp and you have to disconnecte within 24 hours. That's better
It also says "Note:
Do not use this battery charger to charge batteries
larger than those typically found in boats,
passenger cars, or light trucks"
Why would that be???
About a charger that is 3 levels fancier than mine, it says
"Preactivation of a Discharged Battery
The instructions will bore you but here they are:
Preactivation will raise the voltage in a 12 volt battery to a
level high enough to allow the charger to operate in the
automatic mode. This step is required if you have been
attempting to charge a low or dead battery and the battery
has not been accepting any charge.
Select the START position on the SELECT
Select the highest charging position on the SELECT
SETTING switch. (Not the Start setting.)
Charge the 12 volt battery for 515 minutes
Select the CHARGE position on the SELECT
The battery should now accept the charge and the
amperage meter should indicate 615 amps. If not, the
battery should be professionally tested. If battery is okay,
call Technical Service at (866) 236-0044"