Note: Descriptions are shown in the official language in which they were submitted.
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TWO TERMINAL BATTERY
Field of the Invention
The present invention is directed to a two terminal battery, useable
for example in an automobile. The present invention is more particularly
S directed to a two terminal battery including dual batteries within a single
case
having two terminals.
Background of the Invention
The automobile industry is continuously looking for new methods
and systems which will provide an intelligent car battery capable of taking
into
account the activity of the car in order to more efficiently and effectively
provide
power for operating the various systems within the increasingly more
complicated
automobile. Intelligent batteries in general are known in the arc. The
intelligent
batteries typically consist of twin 12-volt batteries, for example, of the
lead acid
variety. Previous designs have three and four external poles requiring
rewiring
of conventional automobile battery systems upon installation. The development
of a two pole intelligent battery system with dual batteries but only two
external
terminals provides several advantages. Clearly the use of two terminals
instead
of three or four obviates the need for wiring harness modifications and
installation costs to conventional battery wiring systems. Improved
performance
and reliability over conventional batteries is thereby easily available.
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Summary of the Invention
The present invention is directed to a two terminal dual battery
system for use in an automobile. The system includes a housing unit which
holds
dual batteries and a micro-processor based controller requiring only two
external
terminals for connection to a typical automobile battery wiring system. The
two
batteries, contained within a single case, share a common negative external
terminal and a single positive external terminal. One of the batteries is
permanently connected to the external terminals and the other battery, while
permanently connected to the negative external terminal, is coupled to the
positive external terminal via a electromechanical latching relay which when
activated connects both batteries in parallel. The operation of the latching
relay
is controlled by a micro-processor operating under a control algorithm. The
micro-processor operates in response to external parameters and sensed
internal
battery parameters. The relay is a pulse operated bi-stable state electro-
mechan-
ical relay. The relay also incorporates a state sensing electrode to give
fully
closed loop logic verification. All relay state transitions are variable time
buffered with the main program containing appropriate degrees of redundancy
and fail safe back-up systems.
One of the battery sections is constructed fot deep cyclic uses.
This battery section is permanently connected to the external terminals and
normally provides power to run auxiliary loads. The second battery section is
constructed to fulfill requirements of low internal resistance and efficient
short
duration high current output. The second section is periodically connected to
the
external positive terminal via the latch relay.
Brief Description of the Drawings
Figure 1 is a top view of the exterior of the battery of one em-
bodiment of the present tnventton.
Figure 2 is a side elevation view of the exterior of the battery of
Figure 1.
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Figure 3 is an isometric view illustrating the interior elements of
Figure 1.
Figure 4 is a simplified electrical diagram of the embodiment of
Figure 1.
Figure 5 is an external top view of the preferred embodiment of
Figure 1, illustrating embedded conductors, a latching relay, and internal
battery
poles.
Figure 6 is a top view of the exterior of a battery of another
embodiment of the present invention.
Figure 7 is a side elevation view of the exterior of the battery of
Figure 6.
Figure 8 is a simplified electrical diagram of the embodiment of
Figure 6.
Figure 9 is an external top view of the preferred embodiment of
Figure 6, illustrating embedded conductors, a latching relay, and internal
battery
poles.
Detailed Description of the Preferred Embodiment
Referring to the drawings, wherein like numerals indicate like
elements, there is shown in Figures 1 and 2 a two terminal dual battery
apparatus
according to a preferred embodiment of the present invention. The battery
includes an external molded battery case 2 and lid 4. Incorporated into the
lid
4 is an integral ventilation system 6. Also integrated into the lid 4 is a
switch
box 8 containing various electronics (discussed below). A first external
terminal
10 serves as the positive terminal and extends from the lid 4. A second
external
terminal 44 acting as the negative terminal also extends from the lid 4.
Figure
3 illustrates the internal elements of the battery including a starter section
20 and
an auxiliary section- 22 adjacent thereto. The starter section 20 includes a
positive pole 14 and a negative pole 24. The starter section 20 has six plate
groups 28 for providing high current duty. The auxiliary section 22 includes a
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positive pole 26 and a negative pole 16. The auxiliary section 22 has six
plate
groups 30 for providing cyclic duty. The individual battery sections 20 and 22
may be lead acid batteries for providing the type of duty described above.
A simplified electrical diagram of the preferred embodiment of the
present invention is illustrated in Figure 4. The starter section 20 and the
auxiliary section 22 are electrically coupled in parallel between external
positive
terminal 10 and external negative terminal 44. A latching electro-meCti~r<ical
relay (L/R) 32 is connected between the starter section positive pole 14 and
the
auxiliary section positive pole 26. The L/R 32 is also electrically connected
to
a micro-processor and a control electronics section 34. The micro-processor
and
control electronics section 34 is electrically connected to the starter
section
positive pole 14, the auxiliary section positive pole 26, the starter section
negative pole 24, and the auxiliary section negative pole 16. In response to
input
signals, the micro-processor and control electronics section 34 opens and
closes
the L/R 32. When the LlR 32 is opened, only the auxiliary section 22 is
connected to the external battery terminals 10, 44. When L/R 32 is closed,
both
the starter section 20 and the auxiliary section 22 are connected in parallel
across
the external battery terminals 10, 44.
The conductor connections linking the internal-poles of the starter
and auxiliary sections to the external poles are illustrated in Figure 5. The
starter
section positive pole 14 is linked to L/R 32 by a conductor 42. Another
conductor 40 links the auxiliary section positive pole 26 to the external
positive
terminal 10 and the L/R 32. Yet another conductor 46 links the starter section
negative pole 24 to the external negative terminal 44. The external negative
terminal 44 is positioned above the auxiliary section negative pole 16 and is
coupled thereto.
In another preferred embodiment, illustrated in Figures 6-9, the
present invention includes an optional external negative pole link 18. As
shown
in Figure 9, the pole link 18 couples the auxiliary section negative pole 16
to yet
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another conductor 38 which is coupled the external negative terminal 44 and to
the starter section negative pole 24.
The micro-processor and control section 34 (hereinafter referred
to as "the ~.P") monitors and detects various operating conditions of the
battery.
S Based upon these conditions the ~cP 34 controls the L/R operation.
The IcP 34 continuously monitors the following parameters: the
,;.
auxiliary (AUX) section voltage (V,), the starter ( STA) section
voltage~(=Vs), a
vibration sensor output, the AUX section current, a contact state of the L/R,
a
condition of various state flags and various timers.
When necessary, signals input to the ~,P 34 are preconditioned in
various conventional ways, for example, R-C filtering. For example, in the
case
of vibration detection, a raw signal is filtered for frequency response,
rectified
and combined in the uP 34 with a 30 second backward looking time signal to
establish a valid Detected VIBration state and set DVIB=True.
Upon detecting parameter inputs which match pre-programmed
conditions, the IcP 34 sends a signal to a L/R drive circuit to change the
state of
the L/R. The ~cP 34 then verifies the result of the change of state,::. The.
L/R
drive circuit may comprise, for example a FET in series with a L/R coil. The
source of the FET is connected to the negative power rail. The relay coil is
connected between the drain of the FET and the positive STA section terminal
14. A protective diode is connected in reverse bias and parallel with the coil
to
suppress inductive fly-back voltages.
To activate the L/R 32, the IcP 34 applies a voltage signal to the
gate of the FET. The voltage signal activates the FET thereby allowing current
to flow. The current activates the coil which in turn closes the L/R 32. To
open
the L/R 32 the ~P 34 discontinues the voltage signal to the gate of the FET.
In order to enable the ~.P 34 to monitor the state of the L/R 32 a
verify contact is included in the L/R housing. The verify contact is connected
to the ~cP 34. When the L/R 32 is closed the potential on the contacts of the
L/R
32 is also present on the verify contact. 'fhe ~cP 34 determines that the L/R
32
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is closed or open based upon the potential at the verify contact. If the L/R
32 is
to be closed, the ~cP 34 sends a voltage to the FET. The ~P 34 then monitors
the
verify contact. If the ~P 34 does not detect a potential at the verify contact
it will
pulse the FET again. It will repeat the pulse up to l5,times or until the L/R
32
S closes. If the L/R 32 is not verified as having closed after 15 attempts,
the ~cP
34 takes no further action until receipt of a valid instruction to open the
LIR 32
from an "assumed closed" state. Re-verification takes place after cessation
ot'the
"opening" current pulse has been applied to the L/R 32 and an verification
attempts register is reset to zero.
Generally, the battery operates in five states recognized by the ~eP
34: (A) idle or open-circuit, where little or no discharging or charging
occurs:
10.8V < V, < 13V, (B) starting, high current, low voltage, short time period
discharge, (C) charging 13V < V, < 14V for less than 40 minutes, (D)
overcharging V,> 14V and V«s > V~ > 13.2V, where V«s is the voltage of a
system regulator and V~ is the voltage across the STA section 20 and the AUX
section 22 in parallel (E) deep discharging: V, <_ 10.8V for an extended
periof
of time with or without vibration present.
The present invention operates in the following manner. As a
starting condition the battery is in state A. Both the starter-section 20 and
the
auxiliary section 22 of the battery are fully charged (normal state) and the
L/R
is in an open state. In this state, only the auxiliary section 22 is connected
to a
vehicle wiring system coupled to the battery via the external terminals 10,
44.
The vehicle includes a vibration sensor (not shown) connected to
the ~cP 34. The vibration sensor may be a piezo electric vibration detector
circuit, for example. When the vehicle is entered, the vibration associated
with
opening the door or other disturbances will be detected by the vibration
sensor.
In turn, the ~eP 34 sets a "vibration detected" flag (DVIB) to true.
The ~.P 34 checks V,. Since the ~.P 34 will find V, > 10.8V, the
present battery configuration will be maintained, i.e., only the AUX section
connected to a starter motor. A key is set-to a start position engaging a
starter
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solenoid to turn the starter motor. The high current drawn by the starter
motor
will cause the AUX section voltage V, to decrease. The ~cP 34 monitors V,. If
V, remains above a first trigger point (10.8V for example) then the car will
most
likely start. If the car starts the uP 34 will not close the L/R 32. Once the
S vehicle starts and the starter motor load is removed, an alternator charges
the
AUX section, raising V,.
If, however, V, drops below 10.8V, the ~,P 34 will close tie L;/R
32, thereby combining the AUX section 22 and the STA 20 section in parallel
for
a greater combined voltage V~. The combination of DVIB=True and V, <
10.8V monitored by the ~.P 34 causes the ~.P 34 to close the L/R 32. The
starter
motor is now driven by the combined voltage V~. Once the vehicle starts, the
alternator will charge both the STA section 20 and the AUX section 22 in
parallel.
In the situation wherein one enters a vehicle (DVIB=True)
attempts to start the vehicle, and the ~cP 34 finds V, is initially less than
10.8V,
the ~.P 34 will automatically close the L/R 32 thereby combining the AUX
section 22 and the STA section 20 before the starter solenoid is engaged:
'lihis
will ensure the best condition for starting the engine.
As stated above, when the vibration sensor senses a vibration, the
uP 34 sets DVIB=True. The ~P 34 also sets a counter to count to 30 seconds
once the vehicle has started. If the L/R 32 has been closed (due either to
initial
finding of V,< 10.8 V or V, dropping below 10.8V as a result of start
attempts)
and no additional vibration is sensed during the 30 second period, DVIB will
be
set to false. If charging parameters, discussed below, do not require keeping
the
L/R closed, the /cP 34 will open the L/R 32 and disconnect the STA section 20
from the AUX section 22.
Under certain circumstances the vibration sensor will not register
an entry to the vehicle, e.g., sensor inoperable, entry vibration
insignificant, etc.
or 30 seconds may elapse between entry and a start up attempt. In either case,
DVIB will be set to false. Therefore, an initial condition DVIB=True necessary
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for engine starting will not be present. If V, < I0.8V, both battery sections
are
necessary to start the engine. However, because DVIB=False, the L/R 32 will
not close. An additional back-up circuit, connected to V, and the ~,P 34
addresses this circumstance. The ~P 34, through the back-up circuit, monitors
S V, rate of fall (dV,/dt) and V,. If dV,/dt exceeds a preselected value and
V, falls
below a preselected value, the ~P 34 will close the L/R 32. At this point,
closure of the L/R 32 is not dependent on the status of DVIB.
Once the vehicle is started, the ~P 34 begins to monitor charging
parameters. As discussed above, the L/R 32 may or may not be closed once the
vehicle is started, depending upon the value of V,. The ~P 34 monitors V,. If
V, rises above 13V through recharging by the alternator charging system, the
~.P 34 will check the status of the L/R 32. If it is closed, it will remain
closed
and if it is open, the ~cP 34 will signal it to close. Once the L/R is closed,
the
charging system will charge both the AUX section 22 and the STA section 20,
1S restoring both sections to their normal state of charge raising V~ to a
maximum
value, as set by an external vehicle voltage regulator.
If the L/R 32 is closed and the engine continues runn~~ngy; both
battery sections are charged with the voltage ultimately reaching a constant
value,
as determined by the vehicle's voltage regulator, for example, 14.2-14.7
volts.
Under these conditions, excessive and prolonged charging of the STA section 20
may cause positive grid corrosion. To address this effect, the ~,P 34
implements
a charge protection voltage (CPV) function. If V~ exceeds 14V, the ~,P 34 sets
a timer for a preselected period T1, for example, 40 minutes. If V~ remains
greater than 14V for the period T1 the ~.P 34 opens the L/R 32. Once the STA
2S section 20 is disconnected by opening the L/R 34, VS naturally decays to an
equilibrium potential, for example, 13.2 volts. When the ~P 34 detects VS has
reached the equilibrium potential, the ~.P 34 closes the L/R 32 and sets a
timer
for a preselected period T2, for example, S minutes. During this period the
STA
section 20 and the AUX section 22 charge in parallel. At the end of the period
T2, the ~cP 34 will open the L/R 32 again allowing the STA section voltage VS
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to decay. Once VS falls below 13.2 volts the ~.P 34 will set the timer to
period
T2 again. The T2 period cycle will continue indefinitely until parameters
require
otherwise. For example, if V, falls below 12.8V the L/R 32 will be forced open
for charging the AUX section 22 alone or if the engine,is turned off, the L/R
will
S be forced open. If V~ falls below 13.2V during either period T1 or T2, the
timer
will be reset to zero so that the next counter implemented will be the one
that is
reset.
When the vehicle becomes idle, the voltages of both battery
sections 20, 22 decay towards their normal open circuit values. When the AUX
section voltage V, falls to the top end of this range, the L/R 32 is pulsed to
the
open state thus isolating the STA section 20 from any standing auxiliary loads
that may be present.
It is preferred that the AUX section 22 provide current to auxiliary
loads that are not or can not be supported by the charging system. If the
vehicle
is idle and an auxiliary load is present and the L/R 32 is open, then the AUX
section 22 alone drives the load. Under this circumstance the STA section 20
is
isolated and V, will steadily decrease with time. In a vibration-free
sit~iatiori; the
AUX section 22 can be fully discharged. However, if V, falls below a trigger
point, for example, 10.8 volts and a vibration is sensed by the vibration
sensor,
e.g., person entry, loud noises, etc. DVIB will be set to true and the L/R 32
will
be closed. The AUX section 22 and the STA section 20 will be placed in
parallel
providing a common voltage V~ (which is greater than 10.8V) to the auxiliary
loads. The ~.P 34 monitors the vibration sensor for further vibrations. If no
vibration is sensed for 30 seconds DVIB is set to false and the L/R 32 is
opened.
The ~eP 34 continuously monitors the vibration sensor. The process is repeated
as called for by the vibration sensor.
This condition can occur, for example, if the vehicle is in use and
there is a charging system failure or long term overburden. If no external
input
is detected when the auxiliary voltage V, falls below the trigger point, then
the
LIR 32 will remain in the open state an$ the AUX section 22 is allowed to
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discharge to completion. This condition typically occurs if the vehicle is
idle and
some accessory, e.g., lights, is left on.
The electronic circuits are dual supplied with current from both
the STA section 20 and the AUX section 22. In the event voltage of both
S sections of the battery falls below 5 volts, then the ~.P 34 will enter a
"sleep"
mode. When the battery is placed on charge and voltage of the AUX section 22
alone or both sections together rises above a preset value, then the ~,P 34
~ill'put
the battery into an "awake" state by a reset and reinitialization circuit to
resume
normal operation.
The present invention may be embodied in other specific forms
without departing from the spirit or essential attributes thereof and,
accordingly,
reference should be made to the appended claims, rather than to the foregoing
specification, as indicating the scope of the invention.
