What is a Smart Battery Charger?

S. Gonzales

A smart battery charger is another name for a microprocessor-controlled charger. These chargers are designed to work only with smart batteries from the same manufacturer. This is because the smart batteries contain special microchips that are programmed to communicate with a charger of the same brand.

A smart battery charger will only work with smart batteries from the same manufacturer.
A smart battery charger will only work with smart batteries from the same manufacturer.

Smart batteries are typically understood to be batteries that are capable of complex functioning. The microchips in them help inform the user of its current state of charge (SoC) and state of health (SoH). They are popularly used in medical equipment, computer devices, video and digital cameras and military tools. As SoC and SoH are important to their functionality, smart batteries are natural matches for these devices. It's important to note that batteries that simply inform a charger to recharge the battery to a certain level are not typically considered to be smart batteries.

Smart batteries, such as a wet cell, may have to be researched before deciding on a specific charger to purchase.
Smart batteries, such as a wet cell, may have to be researched before deciding on a specific charger to purchase.

A smart battery charger is built to make charging precise and because of this, it is unlikely to suffer from overcharging, and trickle charges can be successfully maintained. Smart batteries are equipped with microchips that work with a specific and corresponding charging unit. To make sure that smart batteries are not damaged, consumers should always charge their batteries with the same manufacturer's battery charger. Charging the battery with a foreign charger may result in the nullification of any free or purchased warranties that the consumer has on the battery.

Several types of smart batteries may exist and some consumers may have to research their batteries before deciding on a specific charger to purchase. Maintenance-free, Wet Cell (flooded), Absorbed Glass Mat (AGM), Gel Cell and Valve Regulated Lead Acid (VRLA) are some of the different types of smart batteries that a consumer may have purchased. Documentation to these batteries should be studied before investing in a charger. Business owners who sell battery chargers may often advise customers that one type of smart battery charger can work well with many different types of smart batteries. However, mixing and matching smart batteries and chargers may result in damage.

For consumers who are interested in charging batteries and minimizing expenses, other options exist besides purchasing chargers. Those who are electronically-inclined may also consider building a smart battery charger on their own. Some knowledge of circuitry may be required to achieve this and building should not be attempted by the novice electrician or consumer. Charging batteries this way may also result in voiding warranties or damaging the battery.

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Discussion Comments


@hanley79 - Huh...interesting point you have, there. I guess since they have a circuit, a tiny database, and can communicate and "talk" to other devices like a laptop if the smart battery is a laptop battery, you could consider a smart battery to be a micro computer.

It's not a "usable" type of computer with the ability to apply input through peripherals like a PC or anything, of course, and nothing so complex as a full size computer either, but it's comparable to your calculator example. A smart battery is a very simple, one-task kind of computer.


@Hawthorne - Well, there is something that a smart battery charger does that a regular battery charger doesn't, so that's not entirely accurate.

While the functionality of a smart battery charger is pretty much identical to any other charger, as the article says, smart chargers are designed with a microchip inside that specifically matches the microchips in that kind of smart battery.

This means that you can't mix and match your smart batteries with different brands of smart charger -- the chips will be able to tell that they don't match, and the charger might not even charge the batteries. This means that AA size smart batteries of one brand won't charge in an AA smart charger of another brand, even though they're both AA size and even the same kind of battery.

The microchip matching thing might be a disadvantage for people who like to mix and match their batteries and chargers in case they can't keep track of which kind of battery they're using, but I think it's pretty important as far as quality goes. Mixing batteries and charger types isn't really safe, anyway -- as aishia said in her comment, some batteries in the wrong chargers can explode!

The easy fix for me is to only buy and use one brand of battery and charger. Then there's no chance of mismatching, and the batteries will be working at their best.


@aishia - LOL, no, most chargers these days will tell you whether the batteries are done charging or not. If your AA battery charger has a display for how charged the batteries are in addition to a "done" or "still charging" LED (typically red for charging and green for done), it's fancier than some other types of charger, but that's not what makes it "smart".

See, a smart charger is only called "smart" because it charges the the kind of batteries called smart batteries. The charger does much the same thing that a normal battery charger does, but the smart batteries themselves have little bars on the sides that display how much of a charge they have left in them.

This way you can check to see how much of a charge your batteries still have left in them without actually putting them in the charger -- pretty neat, huh?


So since these smart chargers have microchips inside, does that technically make them micro computers? Even a calculator is a very simple computer; technically things that use microchips are computers, especially ones with so-called "higher functioning".

it seems to me that if you make an auto battery charger that can tell you how charged the batteries are, the charger is the computer. However, the articles says that the batteries themselves report their state of charge and state of health.

I'll assume this is something similar to those AA batteries I bought once that had a little charge reader strip along one side that showed how much juice they had left if I pressed on both ends of the battery. If those have microchips in them, that means the batteries themselves are microcomputers.

How weird is that? Cool, but weird...I wonder if someday we'll have microcomputer batteries that can put themselves inside electronics and get back out again to climb into their chargers automatically whenever they run out of juice.


Oh, so is this kind of like my smart AA battery charger that would show what level of charge the batteries had and change the LED color when they were done charging? I loved that thing, because unlike my old charger, it didn't have the risk of overcharging the batteries.

Apparently with batteries in some not so smart chargers, if you just leave the batteries sit charging for too long, they can overcharge and explode or leak battery acid. Scary thought!

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