Posted by mike on August 22, 2009, 11:05 pm
I have a Battery Minder Plus unit.
The manual makes the following mention and am having a hard time to figure out
Positive(+) terminal is grounded or the Negative(-) terminal as both terminals
several wires running to different directions.
Clearly the manual is suggesting NOT to connect the clips simply to the + and -
This is from pg.5 at
Connecting the BatteryMINDer when Batteries are Installed in the
Follow these instructions when battery is installed in equipment (vehicle, PWC,
boat, tractor, etc.). A spark near battery may cause battery to explode. To
risk of a spark near battery:
1. Position DC output cord to reduce risk of damage by hood, door, covers, or
moving engine parts.
2. Stay clear of fan blades, belts, pulleys, and other parts that can cause
3. Check polarity of battery posts. The POSITIVE (POS, P, +) battery post usually
has a larger diameter than the NEGATIVE (NEG, N, -) post.
4. Determine which post of battery is grounded (connected) to the chassis of
equipment. If the negative post is grounded, see Item N. If the positive post is
grounded, see Item P.
N. For negative grounded equipment, connect the POSITIVE (RED) clip from
the charger to the POSITIVE (POS, P, +) ungrounded post of the battery.
Connect the NEGATIVE (BLACK) clip to the vehicle chassis or the engine
block away from the battery. Do not connect the clip to carburetor, fuel lines,
or metal body parts.
P. For positive ground equipment, connect the NEGATIVE (BLACK) clip from
the charger to the NEGATIVE (NEG, N, -) UNGROUNDED post of the battery.
Connect the POSITIVE (RED) clip to chassis or engine block away from the
battery. Do not connect the clip to carburetor, fuel lines, or sheet metal body
parts. Connect to heavy gauge metal part of the frame or engine.
5. When disconnecting the charger, disconnect it from the AC outlet, and then
remove the clips from the vehicle chassis, and the battery posts.
Connecting the BatteryMINDer when Batteries are Outside of
Follow these steps when battery is outside of vehicle or equipment. A spark near
the battery may cause battery explosion. To reduce risk of a spark near battery:
1. Check the polarity of battery posts. The POSITIVE (POS,P,+) battery post
has a larger diameter than the NEGATIVE (NEG, N, -) battery post.
2. Attach at least a 24 inch long 6-gauge (AG) insulated battery cable to the
NEGATIVE (NEG -) battery post.
3. Connect the (RED) charger clip to (POS+) the post of the battery.
4. Position yourself and free end of cable as far away from battery as possible,
and then connect the NEGATIVE (BLACK) charger clip to free end of the
5. Do not face battery when making final connections.
Posted by Ralph Mowery on August 23, 2009, 12:04 am
What are you hooking the battery minder to ? Most modern cars will have the
negative terminal grounded to the frame. Also most other common equipment
will also such as riding lawnmowers.
Posted by Bruce Richmond on August 23, 2009, 12:38 am
Nearly all cars, motorcycles,ATVs etc are negative ground today. To
be sure just look at the connections. The ground cable will go
straight from the battery to the engine block or frame. The other
cable goes to a post on the starter with a smaller wire going to
provide power to everything else.
Really all you need to know is which terminal is which and they should
be marked right on the battery.
What they are doing is having you make the connections in the way that
is least likely to cause a spark near the battery.
With the charger not plugged in connect the charger wire to the post
that is not grounded. Since the other post is connected to ground you
can connect to most any bare metal you see and it will be the same as
if you had connected to the ground post on the battery. By choosing a
spot away from the battery you don't have to worry about there being a
small spark that could set off hydrogen produced in the battery.
Keep in mind this has all been written with lawsuits in mind. In
practice there is little if any spark when making connections with the
charger not plugged in. Hydrogen is produced when the battery is
charged, so the time you most need to worry about it is when
disconnecting the charger. If the caps are on the cells and you
allowed any hydrogen produced to dissapate there is nothing to worry
about. IMO the most danger due to hydrogen (or gasoline fumes) would
be one a boat.
On many battery tenders for motorcycles there are wires, about the
same weight as those on the charger, that can be attached to the
battery and allow a remote connection without lifting the seat to get
at the battery. One of these would also move any possible spark away
from the battery. (They don't need to be 6-gauge, about as thick as
your little finger, as suggested in the directions. We are talking
about a 1 amp charger here.)
Posted by hls on August 23, 2009, 12:39 am
Find your battery + terminal. The battery is normally marked (+) and (-).
The + is often red and the - is often black.. But not always.
Follow the cables from the battery and see which one is connected to the
chassis. That will tell you which terminal is grounded, NOT which is +
Now, positive (+) is positive no matter whether it is grounded or not.
Same for negative (-).
Posted by Richardson on August 23, 2009, 6:50 pm