||Good battery connections will significantly improve the reliable
performance of your battery. In contrast, poor battery connections may suddenly
cause your system to act as if your battery was dead!
For example, this terminal was connected in our test
vehicle to a 5 year old battery in poor but functional condition. We allowed
the connection to corrode. This battery started the vehicle just fine with no
problems. That is until one hot day during a sales trip. The vehicle started
and operated fine at the beginning of the trip. But after the vehicle was warmed and
the day became hot, we observed the following symptoms:
We parked the vehicle and made a short visit with a customer. When we returned
and attempted to start the vehicle, nothing happened; no lights, no
cranking! It was as if the battery was not there. We
needed to be at our next appointment and soon! Fortunately, our test
vehicle was equipped with a backup battery and and a BIC-75300A.
We were able to quickly switch "ON" the BIC to combine the batteries,
start the vehicle, and make the remaining appointments throughout the day. After
starting with the backup battery, we returned the "Remote Switch" to the
automatic position. But, with the AC on, and the vehicle RPM reduced to idle, the
engine suddenly died. We concluded that the main battery had been electrically
disconnected. So anytime the vehicle load exceeded the alternator output, the system
voltage dropped below the minimum required to operate the engine. Therefore, we
operated with the "Remote Switch" in the ON position for the remainder of the
When we returned, we were able to closely
analyze the failure mode. We observed that the battery had leaked acid through the
top seal (not the vents!) and from the positive terminal. We observed battery acid
all around the battery and the battery tray was wet (with acid). The corrosion on
the clamp was so hardened that a special tool was needed to keep the clamp from moving
while the screw was broken loose. After the clamp was removed, we took it to the lab
for analysis. As you can see in the photo, we observed a black layer on the lead as
well as the hardened yellowish crystels. Measured with an ohm meter, the clamp
showed no conductivity anywhere on the black layer. This layer must be penetrated in
order to achieve an electrical connection. We determined that the leaking acid over
time and hot conditions caused this insulation layer to crystalize to the point of
breaking the electrical connection.
With this kind of problem, a simple jump start would not have helped! Neither
would a battery saver "disconnect" device. The fact is, this battery was near
full charge! When we replaced the battery clamp, the battery performed as
it always had.
|Tips for reliability!
If you use emergency type of battery clamps, best conductivity is made if you solder the
wire after clamping.
2) Seal your cable wire exposure. For a clamp like in the
photo, use something like "Plasi Dip" from NAPA. If you use a crimp type
of clamp, then use a sealing type of heat shrink or "Plasti Dip".
3) Avoid cheap batteries that are prone to leakage.
4) Use corrosion inhibiting felt washers.
5) Ensure your alternator is regulated at the proper voltage (14.0 to 14.7 volts
depending on temperature.)
6) Use of a sealed AGM type of battery will reduce the probability of corrosion