A speaker at a battery conference once said, “The battery is a wild animal and artificial intelligence domesticates it.”

The Intelligent Battery, or Smart Battery, means the battery systems are fully compliant to the Smart Battery System Manager Specification（Revision 1.0  December 15 1998) or other communication protocol, provides outputs from sensors which give the actual status of voltages, currents and temperatures within the battery as well as the state of charge. It can also provide alarm functions indicating out of tolerance conditions.

The Intelligent Battery also contains a memory chip which is programmed by the manufacturer with information about the battery specification such as:-

• Manufacturing data (Name, date, serial number etc)
• Cell chemistry
• Cell capacity
• Mechanical outline code
• Upper and lower voltage limits
• Maximum current limits
• Temperature limits

Once the battery is placed into use, the memory may also record :-

• How many times the battery has been charged and discharged.
• Elapsed time
• The internal impedance of the battery
• The temperature profile to which it has been subjected
• The operation of any forced cooling circuits
• Any instances when limits have been exceeded.

The system also requires devices which may be in either the battery or the charger or both which can interrupt or modify the charging according to a set of rules. Similarly, battery discharge can be controlled by the battery or demand management circuits in the application.

The Intelligent Battery also needs an Intelligent Charger and other devices it can talk to and a language they can speak ,which is referred to as “protocol”.

The charger is programmed to respond to inputs from the battery, to optimize the charging profile, charging at the maximum rate until a preset temperature is reached, then slowing down or stopping the charge and or switching on a cooling fan so as not to exceed the temperature limit and thus avoid permanent damage to the battery. If a deterioration in the battery internal impedance indicates that reconditioning is necessary the charger can also be programmed to reform the battery by subjecting it to several deep charge, discharge cycles. Because the battery contains information about its specification which can be read by the charger, it is possible to build Universal Chargers which can automatically adapt the charging profile to a range of battery chemistries and capacities, so long as they comply with an agreed message protocol.

System Management Bus (SMBus)

The System Management Bus (SMBus) represents a concerted effort to agree on one communications protocol and one set of data. Derived from I2C, the Duracell/Intel smart battery system was standardized in 1995 and consists of two separate lines for data and clock. I2C (Inter-Integrated Circuit) is a multi-master, multi-slave, single-ended, serial computer bus invented by Philips Semiconductor. Figure 1 shows the layout of the two-wire SMBus system.

Figure 1: Two-wire SMBus system.

The SMBus works on a two-wire system using a standardized communications protocol. This system lends itself to standardized state-of-charge and state-of-health measurements.

The philosophy behind the SMBus battery was to remove charge control from the charger and assign it to the battery. With a true SMBus system, the battery becomes the master and the charger the slave that obeys the command of the battery. This enables a universal charger to service present and future battery chemistries by applying correct charge algorithms.

A 50% increase in battery life has been claimed by using such techniques.

State-of-Charge(SoC)

While an ordinary fuel gauge measures in-and-out-flowing liquid from a tank of a known size with minimal losses, a battery fuel gauge has unconfirmed definitions and only reveals the open circuit voltage (OCV), which is a fickle reflection of state-of-charge (SoC). To compound the problem, a battery is a leaky and shrinking vessel that loses energy and takes less content with each charge. As the capacity fades, the specified Ah (ampere-hours) rating no longer holds true. Nor can the fuel gauge assess the capacity by itself; the reading always shows full after recharge even if the capacity has dropped to half the specified Ah.

The simplest method to measure state-of-charge is reading voltage, but this can be inaccurate as load currents pull the voltage down during discharge. The largest challenge is the flat discharge voltage curve on most lithium and nickel-based batteries. Temperature also plays a role; heat raises the voltage and a cold ambient lowers it. Agitation by a previous charge or discharge causes further errors and the battery needs a few hours rest to neutralize.

State-of-charge estimations in a smart battery commonly include coulomb counting, a theory that goes back 250 years when Charles-Augustin de Coulomb first established the “Coulomb Rule.” The principle of coulomb counting, measuring in-and-out flowing energy. One coulomb (1C) per second is one ampere (1A). Discharging a battery at 1A for one hour equates to 3,600C. (Not to be confused with C-rate.)

Are SMART BATTERIES BETTER THAN NON-SMART BATTERIES?

It is important to understand that a SMART battery is simply a better option to an already good design. Whether or not a battery is “smart” has nothing to do with the assurance that the battery is safe, of good quality, is capable of meeting the power requirements of a device or indicate that the battery has no level of intelligence at all. In many cases a non-SMART battery is equipped with very comparable circuitry and processor technology as a SMART battery is, but lacks the communication contacts necessary to interface with host equipment.

Where a SMART battery benefits a user over a non-SMART battery is in its ability to communicate with a user: remaining runtime predictions, remaining useful life, end of discharge/charge warnings, protection modes, and preferred method of charging, etc. Such pieces of information allow a user (via the host equipment) to make better decisions regarding how to best use their battery, especially in situations where the battery is being remotely used.

SMART chargers exist to collaborate with SMART batteries, which typically allow for a faster charge rate, higher operating temperature and early identification of any possible battery faults.

With the above explanation, you maybe have more questions.

For example：

How does a smart battery work?

How long does it take to fully charge a smart battery?

How far can a smart car go with a smart battery?

What is smart battery charger?

How long will a ebike battery use with a smart battery?

PLS contact us and know more about batteries.

Email us at market@kokpower.com